Category: Tuberculosis

Introduction

The article discussed the relationship that exists between HIV-infected people and tuberculosis (TB). The article indicates that there exists a biological synergy between HIV and TB. HIV infection lowers the immunity of a person that makes the person become more vulnerable to TB infection. In the U.S., more than 60% of TB cases originate from foreigners who suffer from latent TB infections before migrating to the United States. In 2010, about 8% of active TB cases happened to patients who suffered from HIV. TB infection remains an important aspect of HIV clinicians in the United States of America. However, the United States of America has recorded a great decline in TB infections in the last decade. The article indicated a decrease of approximately 3% of TB infections in 2010. The clinician put a lot of emphasis on TB because the disease is highly infectious, as well as difficult to diagnose. Moreover, TB is a sensitive illness because the improper medication is dangerous as it can result in the illness becoming resistant to drugs to both the patient and the person to who the patient transmits the infection. Even though there are other factors that increase the risks of TB infection, such as diabetes, malnutrition, immunosuppressive drugs, HIV infection remains the prime factor in TB infection.

What the article is about

TB is an illness caused by the Mycobacterium tuberculosis complex, which are organisms that grow gradually and only recognized with special staining techniques. TB mainly attacks the lungs causing chronic pneumonia. However, TB can also affect other body organs such as bones, liver, and spleen. Transmission of TB occurs when healthy persons come- in contact with the sputum of TB patients who suffer from active TB. Patients with positive-smear sputum are highly infectious. In most individuals, the initial TB infection is controllable by an effective immune response. However, in many cases, the infection leads to latent TB, which may turn reactive and result in active TB later in life. TB infection occurs in two phases. The first infection attacks the lungs and is mainly controllable by the immune system. However, before the immune system makes it inert, it spreads to other organs such as lymph and bones. Then, the immune system contains it from spreading further. It remains in that start until the individual gets a further infection when it reactivates into active TB.

Those people who suffer from HIV are more likely to develop active TB after the initial TB infection because of their immunosuppressant. Primary progressive TB cause chronic pulmonary disease and can cause meningitis. Those individuals who suffer from latent TB and develop immunodeficiency because of HIV-infection are at a high risk of developing active TB (Ahuja, King & Munsiff, 2012).

Claims about Treatment

The article gives important claims about the treatment of TB. For instance, the article posits that TB treatment should commence once a proper specimen that guarantees the identification of TB infection has been established. A person who suspects suffering from TB should take a smear TB test. The doctors should confirm the smear results through NAA testing before commencing medication. The article notes that ART decreases mortality in HIV-infected individuals having active TB, irrespective of the number of initial CD4 cell count. This calls for effective ART initiation for anyone with TB/HIV co-infection. Once the treatment of TB starts, adherence to the treatment is fundamental for the successful treatment of TB.

TB patients should seek treatment mainly in public health institutions where there is patients enhancement to adherence to medication through Direct Observed Therapy (DOT), where every dose taken by the patient is documentable. The documentation is important in enhancing adherence, as well as decreasing the mortality rate of HIV-infected TB patients. The TB patients who suffer from HIV are encouraged to visit government medical institution in order for the HIV clinicians to coordinate their HIV management accordingly with the health department. This is imperative for the proper management of HIV patients to avoid drug reactivity (Dean, Edwards, Ives, 2000; Narita Ashkin, Hollender, 1998).

In conclusion

The article was very important in educating about how TB occurs. TB infection occurs in two phases. The initial infection occurs when an individual suffers from TB when he/she come into contact with the sputum of a patient suffering from active TB. In most cases, the infection is containable by the immunity system. However, this is not the case for those people who suffer from HIV-infection, as they suffer immune-suppression. Therefore, when HIV-infected people come in-contact with TB, causing organisms from the sputum of TB patients, after the initial infection, the TB infection progresses to active TB. The article highlighted the importance of starting TB medication after properly diagnosing the presence of TB specimens through NAA testing. Once the medication commences, the patient should ensure adherence to medication to avoid TB becoming resistant to drugs. TB patients are encouraged to seek medication from government hospitals. Seeking TB medications from government health care facilities is important in making sure that there is appropriate coordination between HIV clinicians and health care to enhance the HIV management process.

Reference List

Ahuja, S, King, L & Munsiff, S. (2012). TB and HIV Coinfection: Current Trends, Diagnosis and Treatment Update. Web.

Dean GL, Edwards SG, Ives NJ. (2000).Treatment of tuberculosis in HIV-infected persons in the era of highly active antiretroviral therapy. AIDS.16, 5, 75-83.

Narita M, Ashkin D, Hollender ES. (1998).Paradoxical worsening of tuberculosis following antiretroviral therapy in patients with AIDS. Am J Respir Crit Care Med. 158, 45,157-161.

Introduction

It has been changing for years, making it difficult to have a single method of curing the disease. In recent years, tuberculosis has been associated with multiple deaths worldwide, with developing countries facing a significant problem in handling the disease. The United States has several infections, and the Center for Control and Prevention (CDC) has been identifying various ways of handling the infection. This essay focuses on tuberculosis infection, prevention and control, surveillance, epidemiology, and significant events.

Tuberculosis Infection

According to the CDC, there were more than 10 million TB cases globally in 2017, with a rate of 133 per 100,000 individuals (MacNeil et al., 2017). In comparison to the previous years data, there was an estimated 1.8% decline in cases observed from 2016 to 2017. On average, TB cases have declined by approximately 1.5% annually since the year 2000. A similar trend was observed in TB deaths, with a decline of 3.9% from 2016 to 2017 (MacNeil et al., 2017). Approximately 920,000 cases of TB and HIV coinfection were accounted for in 2017, representing 9% of the total TB cases observed (MacNeil et al., 2017, p. 263). Additionally, 300,000 deaths were observed among TB patients coinfected with HIV, indicating a case fatality rate of 32.6% (MacNeil et al., 2017). Rifampicin-resistant TB (RR-TB) cases and multi-drug resistant TB (MDR-TB) cases accounted for 558,000 incident cases and 230,000 deaths (MacNeil et al., 2017, p. 263). The case fatality rate among resistant forms of TB was 41% (MacNeil et al., 2017).

Tuberculosis is an airborne infection that implies that the disease is transmitted through airborne particles. When an infected individual coughs, shouts, sneezes or sings, the generated particles get suspended in the air for various hours. When these particles get in contact with a person through inhalation or swallowing, they are transferred to the alveoli of the lungs. When in the lungs, the incubation period for the bacteria is about twelve weeks (Behr et al., 2018). An infected individual becomes contagious during this period and remains contagious as long as the bacteria is in the sputum. Individuals are usually contagious for about two to three weeks after the incubation period.

Tuberculosis treatment involves patients taking a combination of medications based on patient circumstances considering if they have had the disease before or not, which goes up to 6 months with no interruption. These patients have to take a minimum of three drugs as part of the first treatment. This is because fewer drugs can lead to drug-resistant Tb development (Al-Saeedi & Al-Hajoj, 2017). If the patient has never received treatment before, the doctor will have to prescribe Isoniazid, Rifampicin, Pyrazinamide, and Ethambutol (Mase & Chorba, 2019). This follows the probability that the bacteria will be sensitive to all medication and it will not respond to the patients body. The skin test method involves the injection of tuberculin into the lower arms skin. The blood test is done by interferon-gamma release assays (IGRAs).

Prevention and Control

The population-level disease control measure is usually implemented to prevent the further spread of the infection. At this level, the infected individuals are identified, and those with active tuberculosis are treated, making the infection non-contagious. The individuals who have had contact with TB patients are screened to ensure that they do not have active TB (Li et al., 2017). Individuals that are identified to be at risk are then subjected to treatments. Various awareness procedures are set up to enable public members to avoid certain activities that may lead to the spread of TB.

TB patients pose a significant threat to others as the bacteria are airborne. The infected individuals are usually isolated while receiving treatment and removed from isolation within a few weeks of receiving treatments (Xin et al., 2021). The post-exposure prophylaxis for individuals developing active TB can be a supplement in controlling TB. Individuals from places with higher rates of TB infection require post-exposure prophylaxis to help control the TB. However, there are significant challenges to post-exposure prophylaxis, such as exposure gradient, the balance between the benefits and the risks, and post-exposure prophylaxis efficacy (Xin et al., 2021).

Currently, chemoprophylaxis is the most used method in TB Post-exposure prophylaxis. This preventive treatment has significant efficacy in managing the disease.

Surveillance

Case definitions tend to vary from one health organization to another. The World Health Organization (WHO) provides various case definitions and classifications for TB. In Nevada, TB cases are reported within 24 hours timeframe once the healthcare provider has identified them. The health authority then investigates the cases that are either active tuberculosis or suspected cases. Necessary measures are taken to prevent the spread of the infection. Screening of individuals in contact with active TB is done from 8 to 10 weeks (Nac, 2021). Active and suspected cases are then required to follow TB regulations administered by the State Board of Health. It is crucial to have TB surveillance to prevent an epidemic because the disease is contagious. Furthermore, it helps identify substantial gaps between people and the health systems. This includes X-ray diagnosis areas that reveal abnormalities and extrapulmonary cases that the laboratory has not yet confirmed. TB is a nationally notifiable disease by law in the United States, and it is reportable in the state of Nevada.

Epidemiology

From a global perspective, tuberculosis is a significant problem that affects a large population. In 2020, approximately 1.5 million people died from the infection, including 214,000 people already infected with HIV (Tuberculosis (TB), 2022). TB is identified as the 13th leading cause of death, and on the infectious level, it is second after COVID-19. Africa is the region with the highest prevalence, reporting 226 cases per 100,000 population, followed by Southeast Asia with 217 cases per 100,000 population and the Eastern Mediterranean with 114 cases per 100,000 population (Statista, 2021). The Western Pacific reported 93 cases per 100,000 population, whereas the United States reported only 29 cases per 100,000 population. Europe reported the lowest number of cases of the six regions, with only 26 cases per 100,000 population (Statista, 2021).

During this period, the US had more than 84,000 cases of TB(CDC, 2019). From 1953 to 1984, the number of TB infections decreased significantly, with an average rate of 6% every year (CDC, 2019). In 1985, the total cases of TB were at their lowest, with 22,201 cases (CDC, 2019). TB cases began to rise in 1986 after a significant period since 1953. From 1985 to 1992, the number of TB cases increased from 22,201 to 26,673, representing an increase of approximately 20% (CDC, 2019). However, in 1993, the number of infections decreased, which was experienced for 21 years until 2014 (CDC, 2019). A slight increase in the number of cases was noted in 2015. In 2017, the United States reported a significantly low number of TB cases since it began reporting in 1953.

Special Topics and Significant Events

The major tuberculosis outbreak happened between 1800 and 1990 in North America and Europe. 70%-90% of North American and Europe urban populations contracted the disease by the late 19th century (Barberis et al., 2022). In the United States alone, there were 84,304 cases in 1953 and 79,775 in 1954. In Western Europe, TB was a significant problem during the 18th century as it had a mortality rate of 900 deaths per 100,000 people. Detection of TB that is resistant to the antibiotics such as rifampicin and isoniazid has been enhanced by the development of automated Nucleic Acid Amplification Tests (NAATs) (WHO, 2021). It was discovered that the use of doxycycline, together with Tb medication treatment, resulted in the reduction of the lung cavity size and accelerated lung recovery markers (Miow et al., 2021).

Conclusion

It is a contagious disease that affects a significant portion of the US population and the global community. Currently, the infection hugely affects Asian and African countries. Despite its reduction in infection rates, there are areas where individuals are hugely affected by this condition. Identification of patients infected by TB is an essential measure in curbing its spread. Isolation is an important step in the fight against TB since the disease is airborne and highly contagious. The history of TB shows that it is necessary for the condition to be given maximum attention as it leads to multiple deaths when not treated. It is not selective, as it affects individuals of all age groups. However, various antibiotics have been developed which help treat the infection.

References

Al-Saeedi, M., & Al-Hajoj, S. (2017). Diversity and evolution of drug resistance mechanisms in Mycobacterium tuberculosis. Infection and Drug Resistance, 10, 333-342.

Barberis, L., Braggazi, N., Galluzo, L., & Martini, M. (2022). The history of tuberculosis: From the first historical records to the isolation of Kochs bacillus.Journal of Preventive Medicine and Hygiene, 58(9), 9-12. Web.

Behr, M., Edelstein, P., & Ramakrishnan, L. (2018). Revisiting the timetable of tuberculosis.BMJ, 1-8. Web.

Li, J., Chung, P., Leung, C., Nishikiori, N., Chan, E., & Yeoh, E. (2017). The strategic framework of tuberculosis control and prevention in the elderly: A scoping review towards End TB targets.Infectious Diseases of Poverty, 6(1), 1-9. Web.

MacNeil, A., Glaziou, P., Sismanidis, C., Maloney, S., & Floyd, K. (2017). Global Epidemiology of Tuberculosis and Progress Toward Achieving Global Targets,68(11), 263266. Web.

Mase, S., & Chorba, T. (2019). Treatment of Drug-Resistant Tuberculosis. Clinics in Chest Medicine, 40(4), 775-795.

Nac: Chapter 441A- Infectious Disease; Toxic agents. Leg.state.nv.us. (2021). Web.

Statista. (2021). Tuberculosis incidence worldwide by region 2019 | Statista. Statista. Web.

Tuberculosis (TB). Who.int. (2022). Web.

WHO announces updates on new molecular assays for the diagnosis of tuberculosis (TB) and drug resistance. Who.int. (2021). Web.

WHO. (2020). Definitions and reporting framework for tuberculosis (pp. 1-47). Web.

Xin, H., Jin, Q., & Gao, L. (2021). Conditional expanding post-exposure prophylaxis: a potential new tool for tuberculosis control. ERJ Open Research, 7(1), 1-6.

The dangers of tuberculosis (TB) still form a reality for a large segment of the global population, as it cannot be called a disease of the past, unlike bubonic plague, for instance. TB continues to represent a growing threat, as around 2 million people become its victims annually (Gengenbacher and Kaufmann, 2012, p. 514). Despite the considerable amount of research directed at ameliorating ways to diagnose and treat TB all around the world and the substantial financing, new obstacles emerge that hinder the hopes for the diseases eradication. Antimicrobial resistance is a factor that steadily nullifies the efforts put into the attempts to triumph over TB. This phenomenon may be defined as the natural or acquired ability of the diseases causative agent to maintain vital activity when exposed to medication (Fong et al., 2018). Investigating antimicrobial resistance is a means to possibly enhance the efficacy and overall performance of drugs directed at treating TB.

Antimicrobial resistance makes TB a deadly infectious disease, even in developed occidental countries. Nevertheless, the majority of 1.8 million deaths caused by TB occur in developing countries, which is aggravated by the fact that the treatment of cases caused by drug-resistant Mycobacterium tuberculosis (M. tuberculosis) strains requires second-line drugs. The reasons for the formation of drug resistance are different and may vary from medical errors in the development of treatment regimens to the lack of funding and the use of less effective, cheaper drugs. The gravity of the situation is illustrated by the discovery of streptomycin, which was effective only during the first months of TB treatment. An array of different ineffective drugs followed streptomycin until rifampicin was introduced and shortened the treatment duration sufficiently. Thus, while a TB vaccine is unavailable, the need for effective medication is especially heightened.

Understanding the mechanisms of antimicrobial resistance in M. tuberculosis is another crucial element in limiting the spread of new unsusceptible strains. Antimicrobial Resistance in Mycobacterium Tuberculosis: Mechanistic and Evolutionary Perspectives is an article that investigates in-depth the process under consideration (Gygli et al., 2017). A variety of mycobacterial species are involved in studying the processes that allow M. tuberculosis to stay vital under drug exposure: they are favored for the procedure because of their faster growth and biosafety requirements. The differences in genome between these mycobacteria (M. smegmatis, for instance) species and M. tuberculosis restrain the extent to which the research results may apply to the latter.

The resistance that M. tuberculosis possesses may be explained by several inherent characteristics of mycobacterial cell walls. First of all, mycobacterial cell walls are thicker and hydrophobic due to their composition rich in lipids and mycolic acids, preventing the infiltration of hydrophilic compounds. Thus, the success of M. tuberculosis as a pathogen may be partially contributed to the way its walls function and their structure (Maitra et al., 2019). Secondly, the low number of porins, a membranes channels, worsens a cells diffusion capacity. Membrane fluidity, the facility with which molecules move in the membrane environment, is quite low in M. smegmatis  another contributing factor to drug resistance. Hence, the features of mycobacterial cell walls that complicate the spreading of antibiotic molecules serve as a specific basis for antimicrobial resistance in TB.

Cell wall penetration is only the first obstacle that antibiotic molecules encounter on their way, as several inactivation mechanisms are present in M. tuberculosis cells. The first is enzymatic cleavage, a process of breaking the peptide bonds between amino acids in proteins that renders drugs ineffective. Chemical modification, for instance, methylation, is another mechanism that is performed by enhanced intracellular survival protein (Eis). Eis is known to inactivate some of the injectable second-line drugs. Besides the described inherent mechanisms of drug resistance, new ones continue to emerge, complicating the process of finding an effective treatment even further.

The importance of investigating efflux systems for developing drug resistance in M. tuberculosis becomes an increasingly noticeable, although controversial concept. An efflux system, a system of pumps that removes unwanted toxic substances from a sale, is potentially a significant contributor to antimicrobial resistance, especially to isoniazid, an antibiotic used for TB treatment. Efflux pumps may be crucial to understanding macrophage infection, as macrophage constitutes the host organisms primary defense against pathogens. Gene expression of efflux pumps in M. tuberculosis can be prompted by several antituberculous drugs, a result that is invalidated by the absence of correlation between strains. Nonetheless, the efflux system, seemingly, participates in developing drug resistance, and its inhibitors may be incorporated into lowering the concentration of chemicals that prevents bacterial growth in antituberculous medication.

The discussed above inherent drug resistance constitutes a smaller percentage, conceding to the acquired type. Acquired drug resistance may be considered a consequence of chromosomal mutations that stem from several various mechanisms, resulting in different levels of drug resistance. Drug target alteration is one of the most common mutational devices, diminishing the degree to which medications attach to proteins within the blood, and thus limiting the resistance. Abrogation of prodrug activation, another subtype, results in the insusceptibility to some of first-line (isoniazid and pyrazinamide) and secondline drugs (ethionamide and para-aminosalicylic acid, for instance). In this way, the abundance of how M. tuberculosis may adapt to gain better longevity renders TB as dangerous as it is nowadays.

Several factors of the relatively fast evolution of M. tuberculosiss well-adapted strains may be attributed to the human element. Incompetent application of control measures, interrupted drug supply, drugs of low quality, and patient non-adherence may all contribute to the process, although their influence is not sufficient to explain it thoroughly. The evolution of drug resistance and treatment failure may be the result of the actual doses used, which seemingly are insufficient to produce an amount of a drug able to sterilize. The variable degree of drug perforation into TB lesions is another contributing factor. The prescription of standard second-line drugs in the presence of primary drug resistance, followed by their replacement, as well as intermittent courses of therapy, leads to the accumulation of mutations, which become the main reason for the development of the drug resistance. In this way, it is partially formed as a result of one or more spontaneous mutations in M. tuberculosis genes, which occur predominantly when inadequate medication regimens are used.

Moreover, bacteria fitness is potentially another critical element to understanding the evolution of antimicrobial drug resistance in M. tuberculosis. The growth of the insusceptibility to medication in a bacterial population is related to the rate of drug-resistant mutations, the acquisition of horizontally transmitted genes, and fitness cost in bacteria (Zhan et al., 2020). Bacteria fitness, which may be defined as an ability to replicate, survive and undergo transmission, in the specific case of M. tuberculosis, is enhanced in the presence of antimicrobial medication (Zhan et al., 2020). The rate of replication may be reduced when the drug is absent, and the mechanics of the process necessitate further investigation.

The de novo evolution of drug resistance, a series of genetic mutations present for the first time, is influenced by several factors, among which the most significant are the population size, the mutation rate, and the mutational target size. Determining the individual contribution of each of the elements to the scale of resistance acquisition is a complex process, as the net of relations between them is not clear. The size of the bacterial population correlates with the number of cell division events, which increases the chances of drug resistance evolution. Additionally, the earlier these mutations occur in the history of the population, the more substantial part of it will be resistant to the medication in question. The higher cell density increases the chances of encountering drug-resistant M. tuberculosis variants. Nevertheless, measuring the number of bacterial cells in the lungs of a patient is not a trivial procedure. The mutation rate may be described as the frequency with which new mutations occur, and determining its rate for M. tuberculosis may seem improbable because of its long generation time.

Genetic background is a factor that influences the process in question and is the center of heated discussions. The link between the ability to resist the impact of a drug and the diminishing fitness of M. tuberculosis bacteria when the antibiotics are absent is well-established. Isoniazid unsusceptible M. tuberculosis variants were used in studies to support the concept experimentally. Furthermore, drug resistance may be measured by the mutation rate that occurs and its target size. The scale of drug resistance is usually calculated using Luria-Delbruck fluctuation; nevertheless, performing the fluctuations is a laborious task, and the extent to which it is applied is limited. Taking this into consideration, the usual recommendations of medicating TB with a combination of drugs are rooted in its structural specifics.

Four drug-combination may be considered as a possible option for treating TB when the disease is caused by susceptible to medication M. tuberculosis strains. The mechanisms of the approach are grounded in the low probability for a strain to undergo four mutations that would render it resistant to the four medications. However, if the M. tuberculosis strains already possess a certain degree of resistance to one of the drugs, the chances of becoming fully drugunsusceptible are higher. Thus, similar mutations can occur in the mycobacterial population even before contact with the anti-TB drugs.

The significance of investigating antimicrobial resistance in M. tuberculosis stems first of all from the need to contain the disease, which is complicated by the steadily increasing number of TB strains that are unsusceptible to treatment. The issue is further emphasized by the low number of compounds aimed specifically at TB. The results of the article in question for the rapid development of molecular genetics observed in recent years have opened up opportunities for studying the M. tuberculosis genes that control drug resistance and the mechanisms of its evolution. The most studied genes and mechanisms of drug-resistance formation are for first-line drugs, as shown in the article, and the same issues for second-line medications are to be investigated further. The problem of increasing the effectiveness of measures to prevent the infection with drugresistant M. tuberculosis strains is another topic of interest for research that may be based on the text.

References

Fong, I.W., Shlaes, D., & Drlica, K. (2018). Antimicrobial Resistance in the 21st Century. Springer.

Gengenbacher, M., & Kaufmann, S. H. E. (2012). Mycobacterium tuberculosis: Success through dormancy. FEMS Microbiology Reviews, 36(3), 514532.

Gygli, S. M., Borrell, S., Trauner, A., & Gagneux, S. (2017). Antimicrobial resistance in Mycobacterium tuberculosis: Mechanistic and evolutionary perspectives. FEMS Microbiology Reviews, 41(3), 354373.

Maitra, A., Munshi, T., Healy, J., Martin, L. T., Vollmer, W., Keep, N. H., & Bhakta, S. (2019). Cell wall peptidoglycan in Mycobacterium tuberculosis: An Achilles heel for the TB-causing pathogen. FEMS Microbiology Reviews, 43(5), 548575.

Zhan, L., Wang, J., Wang, L., & Qin, C. (2020). The correlation of drug resistance and virulence in Mycobacterium tuberculosis. Biosafety and Health, 17.

Introduction

Todays population records infectious diseases as the utmost killer presenting the greatest challenge to the global community. Governments in collaboration with health-based organizations are investing numerous resources in mitigating the spread and re-emergence of contagious illnesses. This paper seeks to explore one of the re-emerging infectious diseases the world is facing. Tuberculosis (TB) is a re-emerging infectious disease affecting the worlds population.

Tuberculosis

Tuberculosis is an infectious disease caused by the bacteria Mycobacterium tuberculosis. Typically, the illness attacks the lungs, but sometimes it may affect other body parts, including the kidney, spine, and brain. All persons contracting tuberculosis may not become sick, resulting in two types of tuberculosis disorders that include latent tuberculosis infection (LTBI) and active tuberculosis disease. The Centers for Disease Control and Prevention advocate for prompt treatment of the condition. Hence, persons diagnosed with tuberculosis should seek urgent medication.

Signs and Symptoms of Tuberculosis

Tuberculosis is associated with various signs and symptoms based on the part of the body in which the bacteria is growing. The first common symptom of the disease includes severe cough, lasting for at least three weeks. TB also causes chest pain, which sometimes can result in difficulties in breathing or coughing blood or mucus (Shapiro et al., 2020). Patients suffering from these illnesses also experience loss of appetite, fever, fatigue, as well as night sweats. People with LTBI do not fall sick, and they cannot affect other individuals with the infection.

The diagnosis procedure for tuberculosis entails a physical examination of the body. A physician begins the process by inspecting the presence of swelling in the lymph nodes, followed by listening to the sound of the lungs while breathing using a stethoscope, and recommends further needs for testing the disease. The Mantoux tuberculin skin test (TST) undertaken by inserting a small portion of tuberculin into the skin is the commonly known test of the illness (Warsinske, Vashisht & Khatri, 2019). The results of the examination usually take between 48 to 72 hours to be confirmed. Other procedures used to diagnose TB include a blood test, chest scans, as well as sputum tests.

Factors Contributing to the Re-emergence of Tuberculosis

A number of factors cause the increasing rate and re-emergence of tuberculosis across the world. The global demography is one of the risk factors contributing to this trend in the rate of TB. Growth in the worlds population and prolonged longevity increase the chances for the re-emergence of the disease as people become more densely populated. Another factor is the spread of HIV/AIDs among individuals. Patients who have HIV are at a higher risk of contracting tuberculosis (Borgdorff & Van Soolingen, 2013). Thus, as the world records a rise in HIV/AIDs, the rate of TB infection is also likely to increase. Social injustice is also a significant factor contributing to the re-emergence of tuberculosis. Poor communities, as well as countries, are often attacked by many contagious infections, including TB, due to things like overcrowding, malnutrition, or inadequate health infrastructure. Thus, addressing these issues is significant in preventing the further spread of the disease.

Strategies to Prevent Reoccurrence of Tuberculosis

The severe effects of tuberculosis are worrying to the world population, raising the need for the implementation of preventive measures. This is in line with the goals of healthy people 2020 to decrease tuberculosis. Healthy people 2020 aims to reduce TB infection from 20.4/100,000 people to 14/100,000 people (ODPHP, n.d.). Efforts to prevent the spread of tuberculosis take a number of measures. The first strategy to deter the further spread of the disease requires the responsible stakeholders to identify and treat persons suffering from active TB. Upon administering tuberculosis treatment to a diagnosed patient, the individual becomes TB-free and cannot infect other people. Another measure to mitigate the infection includes creating awareness among populations and informing them of the importance of coughing etiquette. Running campaigns and implementing HIV/AIDs prevention measures is a significant strategy to reducing tuberculosis (Borgdorff & Van Soolingen (2013). THE World Health Organization (WHO) provides the Infection Control Guideline for tuberculosis by recommending that governments implement sensitization programs among citizens to reduce the spread of the disease (WHO, 2019). The guidelines further advocate for prompt diagnosis and treatment of TB patients as a key initiative to eradicating its spread. Therefore, early treatment and mitigation of HIV are significant in reducing TB.

CDC Priority for Public Health Response to Tuberculosis

CDC prioritizes various public health responses to tuberculosis to contribute to the prevention of the disease. Some of the CDC prioritization include drafting and documentation of a global plan and policy for tuberculosis, surveillance, control efforts, and provision of training and education on the disease (CDC, 2020). CDC also prioritizes collaboration among health providers, communities, and academic partners as well as governments to mitigate the infection.

Personal thoughts and role as a Community Health Nurse

The emerging antibiotic-resistant microorganism is worrying to global health. Such microorganisms are likely to affect the worlds population causing millions of deaths or patients experiencing side effects of the infection. As a community health nurse, it is important to embrace strategies to eradicate the spread of infectious diseases.

Research Studies Validating the Information

The research studies validating the information presented in this paper are:

Borgdorff, M. W., & Van Soolingen, D. (2013). The re-emergence of tuberculosis: what have we learned from molecular epidemiology? Clinical Microbiology and Infection, 19(10), 889-901. Web.

Shapiro, A. E., Ross, J. M., Schiller, I., Kohli, M., Dendukuri, N., Steingart, K. R., & Horne, D. J. (2020). Xpert MTB/RIF and Xpert Ultra assays for pulmonary tuberculosis and rifampicin resistance in adults irrespective of signs or symptoms of pulmonary tuberculosis. Cochrane Database of Systematic Reviews, (7). Web.

Warsinske, H., Vashisht, R., & Khatri, P. (2019). Host-response-based gene signatures for tuberculosis diagnosis: A systematic comparison of 16 signatures. PLoS medicine, 16(4), e1002786. Web.

Conclusion

Tuberculosis is a major infectious disease that affected the world today. The condition is associated with various symptoms that include lung pains, prolonged coughing, and loss of appetite, among others. Measures to prevent tuberculosis include prompt treatment, educating the masses, and prevention of HIV/AIDs. Persons diagnosed with tuberculosis should seek urgent medication to deter its spread to other people.

References

Borgdorff, M. W., & Van Soolingen, D. (2013). The re-emergence of tuberculosis: what have we learnt from molecular epidemiology? Clinical Microbiology and Infection, 19(10), 889-901. 

CDC. (2020). Essential Components of a Public Health Tuberculosis Prevention, Control, and Elimination Program: Recommendations of the Advisory Council for the Elimination of Tuberculosis and the National Tuberculosis Controllers Association. 

ODPHP. (n.d.). Global Health. Global Health | Healthy People 2020. Web.

Shapiro, A. E., Ross, J. M., Schiller, I., Kohli, M., Dendukuri, N., Steingart, K. R., & Horne, D. J. (2020). Xpert MTB/RIF and Xpert Ultra assays for pulmonary tuberculosis and rifampicin resistance in adults irrespective of signs or symptoms of pulmonary tuberculosis. Cochrane Database of Systematic Reviews, (7). Web.

Warsinske, H., Vashisht, R., & Khatri, P. (2019). Host-response-based gene signatures for tuberculosis diagnosis: A systematic comparison of 16 signatures. PLoS medicine, 16(4), e1002786. 

Classification of the Organism

Tuberculosis has been a significant global health concern for centuries. This disease is caused by Mycobacterium tuberculosis, which is a pathogenic bacteria belonging to the order Actinomycetales, family Mycobacteriaceae, and genus Mycobacterium (Bandaru et al., 2020). M. tuberculosis belongs to a group of obligate pathogens referred to as the Mycobacterium tuberculosis complex (MTBC). MTBC consists of Mycobacterium bovis, Mycobacterium pinnipedii, Mycobacterium microti, Mycobacterium africanum, Mycobacterium caprae, and Mycobacterium canetti. Scholars have reported that these organisms have distinct phenotypic characteristics and host range, with M. tuberculosis demonstrating less than a 0.05% difference from M. bovis (Kesharwani et al., 2020). However, M. bovis is known for causing cattle tuberculosis infection, but it can cause this illness in human beings.

Organism Morphology and Staining

A bacterial organisms morphology helps in the initial identification of a microorganism in an isolate consisting of other microbes. Morphology is defined by an organisms size, shape, arrangement, and cell structure. M. tuberculosis is characterized by a thin, curved, or rod shape, measuring approximately 0.2 to 0.6 µm by 1 to 10 µm (Lehman, 2020). Additionally, these organisms are nonmotile, non-spore-forming, consisting of thin peptidoglycan and a thick lipid layer. M. tuberculosis is a gram-negative and acid-fast bacillus, facilitated by the thick lipid layer, which does not allow staining with regular dyes. This layer provides this microorganism with its distinctive acid fastness. The dyes used for staining and identifying this bacteria are carbol fuchsin and methylene blue (Highsmith et al., 2019). The staining techniques used for the identification are the Ziehl-Neelsen and Kinyoun methods. The carbol fuchsin stains the thick lipid layer of mycolic acid into a pink color.

Pathogenicity

The pathogenicity of an organism is defined as the processes involved in the development and progression of a disease. All the members of MTBC cause tuberculosis, with M. tuberculosis classified as the significant pathogenic organism causing this infectious illness in human beings. This bacteria attacks the hosts immune system  macrophages or phagocytic cells in the alveoli (Farver & Jagirdar, 2018; Kesharwani et al., 2020). This process enables it to prevent the hosts immune cells from recognizing its presence in the body. During an infection, the macrophages or phagocytic cells identify foreign particles and digest them, leading to the boys protection. However, with M. tuberculosis, the bacteria prevent these immune cells from attacking it or being recognized by defending the macrophages degrading mechanisms, making it reside unrecognized within the bodys immune system (Farver & Jagirdar, 2018; Kesharwani et al., 2020). As a result, M. tuberculosis can remain in the cells of these organs for more extended periods in a latent state.

The pathogenicity of M. tuberculosis arises from its cell wall structure. This organism is a gram-negative and acid-fast bacteria composed of a thin peptidoglycan layer and a thick lipid structure consisting of mycolic acid, cord factor, and WAX-D (Kesharwani et al., 2020). Mycolic acid forms a solid protective shell around the M. tuberculosis cell wall, which affects the permeability of a hosts immune cells. Additionally, this lipid structure enables the bacteria to evade the phagocytic process of lysozymes, and other immune destructive components, preventing the action of the complement system on foreign materials (Kesharwani et al., 2020). The cord factor allows the bacteria to assume a distinctly long and slender format, demonstrating its virulence in the hosts cells. Finally, WAX-D helps the bacteria to evade phagocytic cells or macrophages.

The transmission of tuberculosis occurs due to inhalation and deposition of M. tuberculosis bacteria nuclei droplets into the respiratory bronchioles or alveoli. The droplets pass from an individual with an active infection through coughing, talking, and sneezing (Highsmith et al., 2019). The alveolar macrophages engulf the bacteria in these droplets and initiate an immune response. However, the ability of this microorganism to evade the immune response makes the bacteria survive within these cells and proliferate intracellularly (Highsmith et al., 2019). Afterward, the bacteria move to hilar lymph nodes and spread to other body organs through the thoracic duct.

The hosts immune system responds depending on its cellular ability to fight foreign materials. In individuals with adequate cellular immunity, the macrophages secret interleukin 12 and tumor necrosis factor-alpha, which recruit T cells and natural killer cells resulting in an increased inflammatory reaction (Lehman, 2020). The latency of M. tuberculosis begins after the cellular-mediated immune response has contained the bacteria through the formation of granulomas two to 10 weeks after contagion. Differentiating T cells results in the formation of helper T-cells type 1, which releases gamma interferon (IFN-³) (Lehman, 2020; Highsmith et al., 2019). In the infection site, the IFN-³ stimulates macrophages to destroy the microorganism. This process further results in regression and healing of the primary lesion.

Immunologists have reported that the pathologic features of tuberculosis are caused by the hypersensitivity reaction to the mycobacterial antigen. Minimal antigen with increased hypersensitivity reaction may form a granuloma, which may destroy M. tuberculosis (Lehman, 2020). Afterward, healing occurs, followed by calcification and scar formation. With increased antigen and hypersensitivity, tissue necrosis occurs because of the degeneration of enzymes from macrophages. Granulomas are protected from phagocytosis due to the protective covering of fibrin. However, caseous material may form at the primary lesion site as a result of the formation of a semi-solid amorphous material at the necrosis site (Lehman, 2020). The bacteria may not be completely eradicated after healing the primary infection. Consequently, it remains dormant in granulomas, which can be reactivated into an active state upon exposure to factors contributing to immunosuppression.

Disease Caused by the Organism

M. tuberculosis causes an infectious disease predominantly affecting the lungs known as tuberculosis. This malady progresses from the lungs to other body parts and is classified into latent and active states. The latent state is whereby the bacteria persist in an inactive form inside the body organs. The organism does not cause any symptoms or become contagious in this state (Kesharwani et al., 2020). However, it can become active at any moment, especially when an individuals immune system is compromised. In the active state, M. tuberculosis causes symptoms and transmissions in its later stages of infection.

M. tuberculosis causes three types of tuberculosis  primary tuberculosis, reactivation tuberculosis, and extrapulmonary tuberculosis (EPTB). Diagnosis of primary tuberculosis is aided by using the positive purified protein derivative (PPD) skin test and assessing the prevailing signs and symptoms. The bacteriologic finding is that primary tuberculosis may be insufficient, with a 25-30% positivity rate when the sputum or bronchial washing is cultured (Lehman, 2020). A failed cellular immunity and bacilli multiplication might result in progressive active pulmonary tuberculosis development. Meningeal or military (disseminated) tuberculosis may occur in children or older adults with primary infection, immunodeficient individuals, or those with massive lymphohematogenous dissemination (Lehman, 2020). A small percentage of adults with this malady might experience progression into an active disease, which resembles reactivation tuberculosis in older adults. The difference between these illnesses can be seen determined using positive PPD skin test results in previously negative patients.

Reactivation tuberculosis occurs after latent M. tuberculosis is exposed to a weak immune system. A weakened immune system can be due to alteration or immunosuppression. The probability of occurrence of reactivation tuberculosis after initial diagnosis using the PPD skin test is about 3.3%. However, this illness has a 5-15% chance of happening in an immunocompromised patients lifetime (Lehman, 2020). The progression varies depending on the patients age, bacterial intensity, and exposure. Finally, the risk factors for this malady include malnutrition, alcoholism, low-socioeconomic status, immunosuppression, incarceration, and AIDS.

EPTB is less common than other types of tuberculosis infections. This disease is usually seen among patients diagnosed with HIV and pulmonary tuberculosis. EPTB is significantly contributed by risk factors such as HIV and aging occurs in almost all patients diagnosed with HIV (Farver & Jagirdar, 2018; Highsmith et al., 2019; Lehman, 2020). However, the association between EPTB and HIV is less understood compared to HIV to other types of tuberculosis. EPTB occurs in almost any organ in the body. Consequently, diagnosing this ailment is challenging since clinical sample collection is crucial due to insufficient bacteria and the inaccessibility of the affected organs (Highsmith et al., 2019; Lehman, 2020). The malady forms seen in EPTB are lymphadenitis, pleural, gastrointestinal, skeletal, meningeal, peritoneal, genitourinary illnesses, and military tuberculosis  rampant among children and individuals diagnosed with HIV. These maladies have varying signs and symptoms depending on the organ affected.

Signs and Symptoms of the Illness

The signs and symptoms of tuberculosis this illness depend on the type of the disease. Pulmonary tuberculosis is characterized by nonspecific early signs and symptoms such as nonproductive cough, fatigue, anorexia, shortness of breath among children, weight loss, night sweats, or a low-grade fever (Highsmith et al., 2019; Lehman, 2020; Prasanna & Niranjan, 2019). Additionally, the malady causes a cough that progresses into a more frequent mucoid or mucopurulent sputum. This progression might cause an advanced pulmonary tuberculosis infection associated with hemoptysis, chest pain, and sometimes dyspnea. Reactivation tuberculosis is composed of insidious symptoms similar to those of pulmonary tuberculosis. However, many patients diagnosed with reactivation tuberculosis exhibit a productive cough, chest pain, and fever, but about 20% may fail to show any signs and symptoms (Highsmith et al., 2019). Further, about 25% of all cases of reactivation tuberculosis are characterized by hemoptysis due to cavitation and necrosis. Therefore, the PPD test is slightly inaccurate when diagnosing reactivation tuberculosis. The reliable tests include sputum culture, gastric aspirates, or bronchoscopy specimens. Finally, EBPT signs and symptoms depend on the organ affected.

Treatment Methods

Tuberculosis is a significant global health and scholars have made significant efforts to eradicate it from humanitys existence. This illness is commonly treated by administering more than one antimicrobial agent to prevent drug resistance for at least six months and nine months for HIV-infected patients (Highsmith et al., 2019; Prasanna & Niranjan, 2019). The common first-line drugs used are isoniazid, rifampin, ethambutol, and pyrazinamide. The second-line therapeutic agents  fluoroquinolones, streptomycin, capreomycin, amikacin, ethionamide, cycloserine, para-aminosalicylic acid, linezolid, and bedquiline  are administered if the bacteria are resistant to the first-line medications (Highsmith et al., 2019; Prasanna & Niranjan, 2019). However, these medications have less potency than first-line medicines and are difficult to administer due to severe, frequent side effects.

Laboratory technologists must conduct susceptibility testing before these drugs are administered to patients or the regimens are changed. In the first two months, four medications  isoniazid, rifampin, pyrazinamide, and ethambutol  are prescribed, which provides adequate protection for pulmonary, EPTB, and primary tuberculosis (Farver & Jagirdar, 2018; Highsmith et al., 2019; Prasanna & Niranjan, 2019). The duration of treatment depends on the sputum results, cavitation as evidenced in chest x-rays, and susceptibility of the bacteria.

References

Bandaru, R., Sahoo, D., Naik, R., Kesharwani, P., & Dandela, R. (2020). Pathogenesis, biology, and immunology of tuberculosis. In P. Kesharwani (Ed.), Nanotechnology-based approaches for tuberculosis treatment (pp. 125). Academic Press.

Farver, C. F., & Jagirdar, J. (2018). Mycobacterial diseases. In D. S. Zander & C. F. Farver (Eds.), pulmonary pathology (2nd ed., 201216). Elsevier.

Highsmith, H. Y., Starke, J. R., & Mandalakas, A. M. (2019). Tuberculosis. In R. W. Wilmott et al (Eds.), Kendigs disorders of the respiratory tract in children (9th ed., pp. 475497.e5). Elsevier.

Lehman, D. (2020). Mycobacterium tuberculosis and nontuberculous Mycobacteria. In C. R. Mahon, & D. C. Lehman (Eds.), Textbook of diagnostic microbiology (6th ed., pp. 2-21). Elsevier Saunders.

Prasanna, A., & Niranjan, V. (2019). Classification of Mycobacterium tuberculosis DR, MDR, XDR isolates and identification of signature mutation pattern of drug resistance. Bioinformation, 15(4), 261268.

Introduction

Mycobacterium tuberculosis (Mt) is the organism that is responsible for causing tuberculosis (TB). This disease that existed as from the Neolithic era has been a quagmire to the medical field scientists even after the identification of the causative agent. This paper discusses M. tuberculosis with special focus on its structure and physiology, pathogenesis, epidemiology of the disease, treatment and prevention of the infection. Mycobacterium tuberculosis is a challenging bacterium due to its drug resistant tendencies that makes tuberculosis to continue spreading thus prompting for research into a vaccine or drugs that can overcome drug the resistance characteristic of the organism.

Structure and physiology of M. tuberculosis

Mycobacterium tuberculosis is classified as follows: Bacteria; Actinobacteria; Actinobacteridae; Actinomycetales; Corynebacterineae; Mycobacteriaceae; Mycobacterium; Mycobacterium tuberculosis complex (ExPaSy Proteomics Server, para 1). The organism is an acid-fast bacillus (rod-shaped). Its cell wall contains myoacid that is responsible for its acid-fast characteristic and the cell wall also makes it impenetrable to oral fluids since it is highly hydrophobic (due to it glycolipids and lipids). M. tuberculosis is barely affected by alkaline or acidic environment in addition to its resistance to complement lysis. The growth of M. tuberculosis is very slow and it takes up to 12 hours to replicate. In addition, the tubercle bacilli flourish in oxygen rich tissues since they are obligate aerobes. It is for this reason that the bacterium mainly infects the upper lobes of the lungs.

Pathogenesis and epidemiology

Human beings are the only known natural reservoirs of M. tuberculosis. The cell wall of Mt has neither extoxins nor endotoxins and its multiplication occurs in a phagosome. The phagosome avoids fusion with lysosome and thereby enzymatic degradation through production of exported repetitive protein. Two kinds of lesions are developed depending on the response from the host as well as the presence of Mt. Since the first site of infection is mainly the lungs, an exudative lesion occurs here (mostly lower in the lobes) as an acute inflammatory response.

A Ghon complex is an exudative lesion from both the parenchyma and lymph nodes. Other than the primary lesions located in the lower lobes of the lungs, the well oxygenated apices harbor the reactivation lesions. Reactivation lesions can also be located in the brain or bones since they are also well activated. The secondary lesion contains tubercle bacilli encapsulated by epithelioid cells and the lesion is known as a granulomatous lesion.

After the initial infection in the lungs, Mt can spread to other parts via erosion of tubercle or dissemination. The tubercle usually empties into the bronchus and spreads the disease agent to the rest of the lungs and the infection can be spread to other people through expectoration. The infection can also spread to the gastrointestinal tract following swallowing. The organism is capable of disseminating through the bloodstream and consequent spread to other parts of the body.

According to Mazurek et al., (para 7), it is estimated that up to 9 million new M. tuberculosis infections occur every year. In addition, an approximate 2 billion people have latent Mt infection. With about 3 million deaths resulting from Mt infections occurring every year, Mt is classified as the microbial agent that causes most deaths. Mt is passed from one person to the other through respiratory aerosol thus initial infection occurs in the lungs. Mt infections and TB cases are predominant in developing countries with up to 90% of the cases occurring in these nations. Moreover, a new TB infection arises every second (eMedicinehealth, para 14).

In the United States, active tuberculosis is 4.2 cases in 1000,000 persons according to 2008 estimates which reduced to 3.8 cases in 100, 000 persons in 2009. As of 2000, the prevalence rate of latent tuberculosis infection in the U.S. was 4.2 percent (Mazurek et al., para 8).

Diagnosis, treatment and prevention

Mycobacterium tuberculosis is diagnosed using a number of tests with chest x-ray being a leading diagnostic test to detect abnormalities in the lungs. A Mantoux (tuberculin) skin test is an immunologic test is also a common Mt test which tests the infection even when symptoms are absent. Interferon gamma release assays (IGRA) have also been developed to detect Mt. According to Mazurek et al (para 5), IGRAS detect sensitization to M. tuberculosis by measuring IFN-y release in response to antigens representing M. tuberculosis.

One of the already approved IGRA test is the QuantiFERON-TB Gold test. Sputum test is a confirmatory test for TB since the test detects the acid-fast bacilli. A culture of body secretions (including sputum) detects M. tuberculosis through growth of mycobacterium and the culture takes up to 12 weeks.

M. tuberculosis usually exhibits drug resistance hence multiple drugs are used in the treatment of the disease. Isoniazid had been the most common drug. To treat pulmonary TB, a combination of INH, rifampin and pyrazinamide is used with pyrazinamide running for 2 months whereas INH and rifampin are continued for 6 months. Ethambutol is a fourth drug that is used for up to 12 months in cases where there is INH resistance or in immmunocompromised patients.

It is notable that once the patient initiates treatment, the sputum is rendered noninfectious in 2-3 weeks. As a preventive measure, an attenuated vaccine has been produced from M. bovis but this confers partial resistance only and it cannot protect against infection. It is therefore advisable that other than using the vaccine as a prevention strategy, all milk should be pasteurized before consumption as this is helpful in avoiding intestinal tuberculosis. To improve host resistance to the organism, improved nutrition as well as housing is advocated for. Moreover, medical personnel can avoid Mt infection through sterile isolation procedures as well as using masks when handling the organism.

Since M. tuberculosis has continued to exhibit multiple drug resistance, it has become increasingly hard to treat TB. There is certainly need for new vaccines that can be used to completely control the infection whereas new drugs need to be developed to overcome multiple drug resistance. With detection of drug resistance genes in the Mt genome, it is expected that drugs that target the resistance genes will be developed as a new approach to preventing and treating TB. There are also prospects in development of recombinant vaccines in place of attenuated vaccine. While considering new prevention and treatment strategies, it is important to consider the effects of the new developments on immunocompromised persons since they are more prone to M. tuberculosis infection (Smith, p. 495).

Conclusion

Mycobacterium tuberculosis is one of the challenging microbial agents as it leads to a drug resistant infection known as tuberculosis. The acid fast bacillus primarily infects the lungs forming lesions as the organism multiplies in phagosomes. With one third of the worlds population being infected by this highly virulent organism that leads to many deaths, there is need to enhance diagnosis, treatment and prevention of the infection.

Multiple drug resistance must be countered by targeting drug resistance genes while recombinant vaccines should be developed to ensure that TB spread is effectively prevented. It will also be helpful to enhance host immunity through improved diet and housing as a way of preventing infection and disease. Without such measures, M. tuberculosis infection, disease and deaths thereof will continue plaguing human beings even in the 21^st century.

Works Cited:

eMedicinehealth. Tuberculosis. 2010. Web.

ExPaSy Proteomics Server. HAMAP: Mycobacterium tuberculosis complete proteome. 2010. Web.

Mazurek, Gerald H., Jereb, John and Vernon, Andrew et al. Updated guidelines for using interferon gamma release assays to detect mycobacterium tuberculosis infection  United States, 2010. CDC. Recommendations and Reports, 59(RR05):1-25.

Smith, Issar. Mycobacterium tuberculosis pathogenesis and molecular determinants of virulence. Clinical Microbiology Reviews, 13(3); 2003: 463-496. Web.

History of the Organism

According to the National Institute of Allergy and Infectious Diseases (NIAID), evidence of Mycobacterium tuberculosis (Mtb) has been found in ancient Egyptian mummies (par. 3). Tuberculosis (TB) was also a prevalent disease in the ancient Roman and Greek civilizations. Overcrowding in 17^th-century cities made TB a major public health threat. Significant 19^th-century scientific advances, including Kochs discovery of the causative agent of TB (Tuberculosis Mycobacterium) in 1882, laid the groundwork for TB diagnosis and drug development (NIAID par. 8). The 1921 development of the Bacille Calmette-Guerin (BCG) vaccine was a breakthrough in the efforts to combat TB prevalence rates. However, in recent years, drug-resistant TB strains have emerged, presenting a new threat to public health.

Habits and Sites in the Body where it is found

Mtb is a bacillus with an acid-fast cell wall that retains the carbon fuchsin stain even after an acid-alcohol treatment (Bauman 154). It is a non-motile bacillus with a size range of between 3.0µm and 0.4µm. Mtb is an obligate aerobe with a slow growth rate in its human host. Its cell wall is rich in mycolic acid and lipids, which make it impermeable to most substances, including common antimicrobials (Bauman 161). The microorganism primarily occurs in the lungs of infected individuals but can infect the kidneys, spine, and brain (Centers for Disease Control and Prevention (CDC) par. 6). Most Mtb infections are latent, but immune-compromised people can develop active TB symptoms.

Worldwide Distribution of the Disease

TB affects people on a worldwide scale with an estimated 2 billion people being infected with Mtb (NIAID par. 2). Geographically, World Health Organization (WHO) identifies Africa as the worst affected region with 280 cases per 100,000 people being reported in 2013 (par.12). TB is also common in parts of Asia and the Western Pacific areas. According to NIAID, in the U.S., 3.6 TB cases per a population of a hundred thousand were reported in 2010; this was a 3.1% drop from the previous year (par. 6). However, the cases were higher among foreign-born persons than among the natives. Other countries showing a sustained reduction in TB prevalence include China, Brazil, and Cambodia.

How the Organism gets to the Host

Mtb is an airborne microorganism that enters its human host through inhaled air. An individual with pulmonary tuberculosis releases these bacteria into the air during coughing, talking, sneezing, or singing (CDC par. 4). Inhaling this air in poorly ventilated conditions introduces Mtb into the lungs, which is the main route of entry of the bacteria into the body. Public Health Agency of Canada (PHAC) states that a cough containing 3000 microns of Mtb is the infectious dose (par. 2). However, Mtb cannot be transmitted through activities such as handshaking, kissing, or sharing of food (CDC par. 6). Proper ventilation is essential in reducing the spread of the microorganism.

Vectors and Reservoirs Involved

The main reservoirs of Mtb are infected humans and animals (PHAC par. 17). Up to a third of the human population harbors the Mtb bacterium, but only shows latent TB, which is symptomatic. Besides humans, other hosts of Mtb include animals such as primates (monkeys), cattle, sheep, pets, and goats. Diseased animals, therefore, act as reservoirs of the bacteria. They spread the microorganisms to humans through aerosols, fomites, and bites (PHAC par. 8). Mtb has no known transmission vector.

The Parts of the Body it affects

Mtb primarily affects the lungs of its human host. Once inhaled, the bacterium finds its way into the lungs where it multiplies in number, which destroys the lung tissue (CDC par. 3). However, in most cases, Mtb remains dormant for a long time in the lungs without causing TB symptoms. Extra-pulmonary Mtb infection can affect other body organs, including the brain, spinal cord, and kidneys (CDC par. 8). Damage to these organs causes diseases such as meningitis, pulmonary lesions, pleuritis, and pericarditis.

How it contaminates and colonizes the Host

Mtb gains entry into the lungs when a person inhales air contaminated with the bacteria. If there is no immediate immune response, Mtb multiplies and enters inactivated macrophages of the alveolar spaces. It then suppresses the acidification process essential for lysosomal enzyme activity and in this way avoids digestion by phagosomes (PHAC). This immune avoidance mechanism allows Mtb to multiply and grow in the alveolar macrophages without inhibition. However, the immune activation of macrophages allows the body to get rid of the bacteria. At a high bacteria load, the immune response produces cytokines that have an inflammatory effect on the lung tissue (PHAC). Mtb infection is more likely to develop into TB in immune-compromised individuals (HIV patients) than in healthy people.

Prognosis

CDC identifies two kinds of prognostic tests for new Mtb infections, namely, the TB blood test and the tuberculin skin test (par. 6). The skin test entails a subcutaneous injection of a substance called tuberculin on the arm. The development of swelling in this area after two to three days is an indication that a reaction occurred. A positive skin test indicates latent Mtb infection. In contrast, TB blood tests determine an individuals immune response to Mtb infection using interferon-gamma release assays. These tests determine how well a persons immunity responds to exposure to TB bacteria.

Mortality Rates

Active TB has high mortality rates among all age groups. WHO reports that, out of the nine million people, who contracted TB in 2013, 1.5 million of them died (par. 5). The mortality rates are higher in low-income countries than in developed ones. Over 95% of deaths caused by TB globally take place in developing countries, where it ranks as one of the top killers of females between the ages of 15 and 44 (WHO par. 6). HIV-positive persons are at a greater risk of dying from TB than non-infected ones. In 2013, 360,000 HIV-infected persons succumbed to TB.

Decline or Increase in Prevalence

The prevalence of TB varies widely depending on the geographical region. A large proportion of TB cases reported in 2013 were from parts of Asia, Africa, and the Pacific regions, representing 56 percent of all the TB infections recorded worldwide (WHO par. 4). TB prevalence is still high in Africa with over a million new cases being reported in 2013 among HIV-infected persons. Overall, China, Cambodia, and Brazil top the list of countries where the prevalence of TB has declined significantly over the last two decades.

A Re-emerging Disease

TB is a re-emerging infectious disease. Its prevalence globally declined significantly with the increased use of antibiotics in TB treatment. However, more recently, antibiotic-resistant strains of Mtb have evolved into multidrug resistant (MDR) TB strains that show resistance to first-line antibiotics, such as rifampicin and isoniazid (NIAID par. 7). In contrast, extensively drug-resistant TB or XDR TB is resistant to both first- and second-line antibiotic therapy. The inappropriate antibiotic treatment causes Mtb to evolve into resistant TB strains. Globally, MDR TB cases are increasing with over 650,000 and 480,000 infections being reported in 2010 and 2013 respectively (WHO par. 21). Even with antibiotic therapy, six out of ten MDR TB patients die from the disease.

Vaccination

Children and infants can be immunized against TB using the Bacille Calmette-Guerin (BCG) vaccine. It is the only available vaccine against Mtb strains. The vaccine contains attenuated Mycobacterium Bovis strains. It is effective against TB in children, but less effective against Mtb in adults (PHAC par. 6). In children, BCG immunization prevents TB-related meningitis. Current vaccine research focuses on attenuated and recombinant Mtb strains.

Medicines Prescribed to Treat the Disease

The treatment of active TB disease involves a course of antibiotic medicines that lasts up to six months. Four first-line antibiotics, namely, isoniazid, oral rifampicin, oral Pyrazinamide, and oral Ethambutol are prescribed for susceptible Mtb strain (PHAC par. 14). The treatment prescribed depends on the susceptibility level of the Mtb strain, which is determined using isolated bacterial cultures. MDR TB, which is resistant to these four drugs, is treated with second-line antibiotics like amikacin, kanamycin, or capreomycin (NIAID par. 11). Normally, a daily dose of three drugs lasting up to three years is prescribed to patients with MDR TB.

My Advice to a Patient Infected with Mtb

I would advise a person infected with Mtb to register with a health care facility to receive appropriate treatment and care. He or she should undergo testing (skin or blood tests) to help treat Mtb infection at its asymptomatic stage before developing into the TB disease and becoming infectious. In addition, testing helps prevent the spread of the bacteria to other people interacting with an infected individual (WHO par. 9). I would also advise the patient to complete his or her course of the prescribed drugs to avoid contracting MDR TB. Treating MDR TB would require a combination of many antibiotics taken over an extended period.

Mutations and Resistance

Drug-resistant Mtb strains arise when there is an inappropriate TB treatment. The failure to finish treatment and the prescription of the wrong dose or low-quality drug can lead to drug resistance. Drug-resistant phenotypes include MDR TB and XDR TB. Mutations confer Mtb its resistance to available antibiotics, making it difficult to treat the disease. The genetic variants are responsible for the resistance to first- and second-line antibiotics.

The Drugs Mtb is Resistant to

The Mtb causing MDR TB is not susceptible to two of the best available antibiotics, namely, isoniazid and rifampin (CDC par. 5). The two drugs are prescribed to treat active TB infections. In contrast, susceptible strains are sensitive to first-line drugs like isoniazid, Ethambutol, rifampin, and Pyrazinamide (PHAC par. 13). On the other hand, XDR TB is highly resistant to both first- and second- group antibiotics. Additionally, it is not sensitive to isoniazid or rifampin. It also exhibits resistance to fluoroquinolones and other TB medicines such as capreomycin, kanamycin, and amikacin (CDC par. 4). As such, the available treatments are less effective against XDR TB.

Factors Contributing to Drug Resistance

One of the causes of drug resistance is the inappropriate use of anti-TB medicines (CDC par. 5). Failure to finish a treatment course, wrong drug prescription, inadequate dosage, low-quality drugs, lack of drugs, and incorrect timing during drug administration are the leading causes of drug resistance by Mtb bacteria (CDC par. 7). Infected individuals, who fail to adhere to the treatment instructions or take drugs as instructed are at risk of developing MDR TB. Recurrent TB infections can also lead to MDR TB in recovering patients.

Works Cited

Bauman, Robert. Microbiology with Diseases by Body System, New York: Person Education, 2014. Print.

Centers for Disease Control and Prevention. Tuberculosis. 2015. Web.

National Institute of Allergy and Infectious Diseases. Tuberculosis (TB). 2015. Web.

Public Health Agency of Canada. Mycobacterium Tuberculosis Complex. 2015. Web.

World Health Organization. Fact Sheets: Tuberculosis. 2015. Web.

Causes, Symptoms, Transmission, and Complications

Tuberculosis (TB) is an infectious disease that is caused by a rod-shaped bacterium. The bacterium is referred to as Mycobacterium tuberculosis. TB occurs in different forms, the type responsible for most infections is the pulmonary TB. According to CDC (2014), it is responsible for approximately 85% of the infections. In addition, the signs and symptoms of pulmonary TB may occur before the diagnoses of the other types of TB. The main symptoms include recurring fever, persistent cough that may last for weeks, hemoptysis, chest pain, fatigue and loss of weight (Oliveira et al., 2012). TB is normally spread through the air. This implies that the Mycobacterium tuberculosis particles are transmitted by airborne. The particles are called nuclei, and their measurement ranges from 1-5 microns in diameter (CDC 2014). Oliveira (2012) states that the droplets nuclei are generated and passed to the air when a person suffering from pulmonary TB sneezes, coughs, shouts, and or sings (p. 2148). The participles can stay in the air for some hours (Oliveira, 2012). Thus, people exposed to the conditions are likely to be infected.

Complications

The effects of the TB infections differ depending on the person and the level of exposure. As a result, some people may not develop complications. However, other people may have mild to severe complications, which may lead the damage of vital body organs such as lungs. Other complications include cardiac tamponade, meningitis, and malfunction of kidney and liver.

Treatment

The overall objective of the treatment of tuberculosis is to alleviate the suffering it causes to the infected person and to reduce the transmission of the Mycobacterium tuberculosis to other people. The treatment benefits the individual and the community. In addition, the treatment should include the clinical and social issues. The treatment of TB is influenced by different factors. One of the main factors is the type of TB and secondly is the sensitivity of Mycobacterium tuberculosis. Treatment is pharmacological, and it entails the use of different regimes. CDC (2012) recommends four regimes. The selection of the schedules is based on the type of TB and the overall health status of the patient.

Incidence, Prevalence, and Mortality

In the United States, the incidence rate in 2014 was 2.96%. The incidence rate varied depending on different categories of people. For example, the incidence rate for foreign-born persons was 13 times greater than for US-born citizens. The total number of people who died of TB was 555 in 2013. The prevalence of TB in the US varies depending on ethnic orientation. Among the whites, it is 0.6 cases per 100, 000 persons (CDC, 2014).

Determinants of Heath

The determinants of health include the social, personal, environmental, and economic factors that influence health status (Hargreaves et al., 2011). The interrelationships among the factors determine the health of an individual or population. According to Hargreaves et al. (2011), the determinants fall under broad categories of social, health services, individual behavior, policy making, and biological and genetic factors. The social determinants directly linked to the environment in which people or population live, work and age. The social and physical environment determinants influence the health outcome. For example, people in overcrowded areas are likely to have a higher prevalence of TB compared with people with better living conditions.

Health determinants relate to the access of health services. Hargreaves et al. (2011) pointed that limited access or lack of access to health services influences the health of an individual. For example, people who lack funds to go for regular medical checkups may not engage in preventive care. In relation to TB, the lack of health services results in delays in receiving the right care and hence the spread of Mycobacterium tuberculosis. Individual behaviors also influence the health outcome. According to Hargreaves et al. (2011), individual behavior plays an important role in the preventive care. For instance, cautious behavior and regular screening for TB is required especially for the HIV-positive patients and people leaving in regions with high prevalence of TB.

Biological and genetic factors relate to how a disease affects specific population more than the others. This is normally due to inherent biological traits that make a person or population more susceptible. Examples of the biological and genetic factors include age, sex, and HIV status. In relation to TB, HIV-positive patients are exposed to increased risk of being infected with TB.

Epidemiologic Triangle

There are different models of disease causation. One of the models is the epidemiologic model, which is composed of the agent, host, and environment. This implies that disease results from the interaction of the three factors. For a disease to be passed from the agent to the host, there must be a shift in balance in the three components. In relation to TB, the agent is the Mycobacterium tuberculosis, the host is the individual while the environment is the medium of transmission such as the air. The Mycobacterium tuberculosis exists only in humans. In order the bacterium to cause infection, it has to be in sufficient amounts in which the host passes it to the environment. If the host has high opportunities for exposure such as susceptibility due to social and environmental factors, the balance will favor infection. On the other hand, the environment represents the extrinsic factors that provide the opportunity for exposure. For example, a crowded environment, poor socioeconomic standards and lack of health services will lead to the infection.

Role of the Community Health Nurse

The community nurse plays a critical role in the prevention and treatment of TB. The nurses can be involved in the screening of populations in order to identify the patients, who need to be examined, i.e. identification of cases. The nurses should also develop a communication system in which the identified patients are referred to the right health facilities to start the treatment. In addition, the community nurses should compile data on the prevalence and incidence rates in the areas of their work. According to Oblitas et al. (2010), analysis of the data helps in determining the communities that are more susceptible. This data can be used in the policy formulation and the design of the intervention programs. According to CDC (2012) TB develops resistance to drugs if the right treatment schedule is not followed. This has a great implication for the patient, the community, and the government. It leads to multidrug resistance (MDR) TB, which is difficult and expensive to treat. Thus, the nurse should do follow-ups in order to ensure that patients are using drugs as advised.

National Agency that Addresses TB

In the United States, CDC plays a great role in the prevention and resolving the TB. CDC is involved in research and monitoring the trends of TB. For example, CDC developed a strategic plan to eliminate TB in the US in 1989 and outlined the actions necessary to achieve the goal. However, factors such as HIV, MDR-TB and increased immigration of people from countries where TB was common hindered the elimination.

References

CDC. (2012). Principles of epidemiology in public health practice: An Introduction to applied epidemiology and biostatistics. Web.

CDC. (2014). Fact sheet: Trends in tuberculosis, 2014. Web.

Hargreaves, J., Boccia, D., Evans, C., Adato, M., Petticrew, M., & Porter, J. (2011). The social determinants of tuberculosis: From evidence to action. American Journal of Public Health, 101(4), 654-662.

Oblitas, F., Loncharich, N., Salazar, M., David, H., Silva, I., & Velásquez, D. (2011). Nursing s role in tuberculosis control: a discussion from the perspective of equity. Revista Latino-Americana Enfermagem, 18(1), 130-138.

Oliveira, I., Jesus, G., Pinto, P., Balderrama, P., Cury, M., & Vendramini, S. (2012). Tuberculosis control: Evaluation of the nursing team on the framework of health services. Journal of Nursing, 6(9), 2145-2153.

Introduction and background information

Tuberculosis is one of the communicable diseases that pose critical health concerns globally. Although there have been slight declines in tuberculosis prevalence over the last ten years, the disease is still a major cause of deaths with approximately 1.3 million fatalities and almost 9 million new infections reported in 2012 (Sulis, Roggi, Matteelli, & Raviglione, 2014).

Tuberculosis (TB)

Cause and symptoms of TB

TB is a microbial disease caused by the bacterium Mycobacterium tuberculosis, which infects the respiratory system and other body parts, including the kidney, spine, and brain (Centers for Disease Control and Prevention, 2016). The M. tuberculosis infections manifest through multiple symptoms depending on the organ affected. The infection on lungs manifests through prolonged cough, chest pains, and blood coughs. Moreover, TB infection may manifest through weakness/fatigue weight loss, lack of appetite, fever, chills, and sweating at night (Centers for Disease Control and Prevention, 2016).

The transmission of the M. tuberculosis bacteria

The air is the medium of transmission of the M. tuberculosis bacteria. Coughing, speaking, or singing let out the bacteria from an infected person to the air and the bacteria spread to people nearby. It is worth noting that only the bacteria in the lungs/throats can be transmitted from a person to another. Bacteria in other body organs like the kidney/spine are oftentimes non-infectious (Centers for Disease Control and Prevention, 2016).

Complications and treatment of TB

Once the M. tuberculosis bacteria are in a new host, they become active and multiply drastically. The multiplications severity prevent the immune system of the infected person from fighting the bacteria. The drastic complication consequently result in what is commonly referred to as the TB disease making the newly infected person sick and able to spread the bacteria to other susceptible hosts.

TB should be treated promptly and with acute medical adherence. Noncompliance to medications/prescriptions may result in reinfection and drug resistance. Some of the treatment regiments adopted in the US include isoniazid (INH), rifampin (RIF), ethambutol (EMB), and pyrazinamide (PZA). It is also worth to note that the immunity of susceptible hosts can be improved by immunization (Centers for Disease Control and Prevention, 2016).

Demographics of interests

As seen earlier, TB is a major cause of mortality and morbidity in the world. The prevalence of the disease had registered some drops in the last ten years. However, annual mortalities rates go beyond 1.5 million with new cases of infection each year (Srivanitchapoom & Sittitrai, 2016)

Major incidences are reported in populous regions in developing countries, especially in Africa and Asia (Jassal & Bishai, 2010).

The determinants of health in TB

TB is highly dependent on socio-economic and environmental factors. Key determinants of health in TB are economic development levels and living conditions. The prevalence of TB is extremely higher in poor countries (Kolifarhoode, Khorasani-Zavareh, Salarilak, Shoghli, & Khosravi, 2015; Hargreaves, et al., 2011).

Therefore, TB is considered a poverty-related ailment with people in poor economies and living in impoverished environments registering highest mortalities and morbidities. In the poor economies, it is likely to experience other determinants of TB, which include poor dieting/food insecurity, low literacy levels, and unfavourable psychosocial circumstances (Sulis et al., 2014).

Vulnerability and susceptibility to TB infections are high among HIV patients, asylum seekers, inmates, drug/substance addicts, and people without homes.

The TB determinants facilitate the development of the disease in various ways. First, they increase the exposure of susceptible hosts to the M. tuberculosis. Second, they prevent timely and effective intervention and treatment of the diseases. Third, TB determinants inhibit early diagnosis and therefore facilitate widespread infections (Sulis et al., 2014).

The epidemiologic triangle as it relates to TB

Three factors, including hosts, agents, and environmental factors are a key component of infectious diseases. The interlinking relationship among the three components constitutes to what is referred to as the epidemiologic triangle (Venkatraman, Morris, & Wiselka, 2013).

In the spread of TB, there exists a strong linkage among the bacterial, the human host and environmental factors. Environmental factors (the settings in which transmissions occur) such as poor housing/poor living conditions (prisoners/immigrants), poverty, inaccessibility to medical services, and proximity to infected persons are some of the environmental factors that link the bacteria with the human host.

Similarly, the host may facilitate the spread and development of TB bacteria. However, research has revealed that modification of host factors is theoretically possible. Some of the host factors that highly influence transmission include the immunosuppression resulting from other diseases (diabetes/HIV), drug and substance abuse, insufficient Vitamin D, and the use of steroids and other immunosuppressant.

The role of community health nurse in TB management

Community health nurses play significant roles in the management of TB (Ahmed, Soliman, & Awad, 2012). Proper/appropriate nurse performances and nursing competencies have been linked to patients adherence to medication and augmented outcomes.

Nurses play key roles in diagnosis and case finding. They are tasked with the evaluation of patients needs, understanding patients situations/status. As such, they carry out assessments to facilitate active case finding.

Further, community health nurses are tasked with assessing TB patients regarding various issues such as progress, intervention, visit schedules, responses to treatment among other pertinent information. It is highly recommended that the nurses make accurate and clear recording of patient information. Using special formats, nurses should then make reports to relevant physicians and other pertinent stakeholders (Ahmed et al., 2012).

Patient assessment involves collecting data pertaining each case of TB. The data is then analysed to come up with a nursing care plan. Data analysis should be done meticulously to allow proper and effective planning on care provision (Ahmed et al., 2012).

Community health nurse is responsible for TB patients follow-ups and referrals. It is highly recommended that follow-ups are done regularly and frequently to check on treatment adherence, possible medication side effects, and general progress of the TB patients. Where possible home visits should be done in outpatient to ensure treatment continuity. Depending on the conditions, the community nurse should make referrals (Ahmed et al., 2012).

The National Tuberculosis Controllers Association (NTCA) and its role in addressing TB

The National Tuberculosis Controllers Association is national agency in the US that deals with TB issues. From the agencys aim, it is evident that NTCA is committed to aiding the elimination of TB from local to national levels. NTCA has sub-agencies that include the NTNC, the NSTC, and the SETC. Each of the sub-agencies has specific roles that they play in addressing TB (National Tuberculosis Controllers Association, 2015).

In the efforts to reduce the impacts of TB, NTCA has objectives that include providing a collective voice for all pertinent stakeholders in the fight to reduce infections, pushing for enactment of laws and policies that advance TB control and other TB reducing endeavours.

Moreover, NTCA holds periodical events in different cities and states throughout America where it sensitizes, trains, and carries out testing for TB among the US citizens. In the course of facilitating public awareness through training, NTCA works with other organisations like the RTMCs and the American Thoracic Society among others (National Tuberculosis Controllers Association, 2015).

Conclusion

TB is a communicable disease that has high morbidity and mortality prevalence. M. tuberculosis bacteria cause the disease and it is transmitted through direct exposure (with the portal of exit/ re-entry being the respiratory system). Three factors, including the host, the environment, and the bacterial play significant role in enhancing TB transmission.

TB is treatable but needs strict medication adherence. National agencies, community health nurses, and other stakeholders play significant roles it the treating of TB. In addition, the stakeholders make efforts of reducing the spread/prevalence and the effects of TB.

References

Ahmed, A. I., Soliman, S. M., & Awad, L. A. (2012). Validation of Evidence-based Clinical Practice Guideline: Nursing intervention for newly diagnosed pulmonary tuberculosis patients at community setting. Alexandria Journal of Medicine, 48(2), 155165.

Centers for Disease Control and Prevention. (2016). Tuberculosis.

Hargreaves, J. R., Boccia, D., Evans, C. A., Adato, M., Petticrew, M., & Porter, J. D. (2011). The Social Determinants of Tuberculosis: From Evidence to Action. American Journal of Public Health, 101(4), 654662.

Jassal, M. S., & Bishai, W. R. (2010). Epidemiology and Challenges to the Elimination of Global Tuberculosis. Clinical Infectious Diseases, 50(3), S156-S164.

Kolifarhoode, G., Khorasani-Zavareh, D., Salarilak, S., Shoghli, A., & Khosravi, N. (2015). Spatial and non-spatial determinants of successful tuberculosis treatment outcomes: An implication of Geographical Information Systems in health policy-making in a developing country. Journal of Epidemiology and Global Health, 5(3), 221230.

National Tuberculosis Controllers Association. (2015). National Tuberculosis Controllers Association.

Srivanitchapoom, C., & Sittitrai, P. (2016). Nasopharyngeal Tuberculosis: Epidemiology, Mechanism of Infection, Clinical Manifestations, and Management. International Journal of Otolaryngology, 2016(4817429), 1-6. Web.

Sulis, G., Roggi, A., Matteelli, A., & Raviglione, M. C. (2014). Tuberculosis: Epidemiology and Control. Mediterranean Journal Hematology and Infectious Diseases, 6(1), e2014070.

Venkatraman, N., Morris, T., & Wiselka, M. (2013). Current Approaches to the Management of Tuberculosis. Wiley Online, 24(18), 47-50.

Tuberculosis

The respiratory system is a system of organs that are responsible for gas exchange, such as transporting oxygen in and carbon dioxide out of our bodies. Parts of the respiratory system include nose and nasal cavity, sinuses, mouth, pharynx, larynx, trachea, diaphragm, lungs, bronchial tubes, bronchi, bronchioles, alveoli, and capillaries. The respiratory system can be divided into 2 tracts, upper tract and lower tract. The upper tract comes in direct contact with the external environment and includes the nose, nasal cavity, mouth, pharynx, and larynx. The lower tract of the respiratory system begins below the epiglottis in the larynx. The lower tract includes part of the larynx, trachea, lungs, bronchial tubes, bronchi, bronchioles, and alveoli. The primary organs of the respiratory system are the lungs. The lungs work with the circulatory system by taking in oxygen and diffusing it into the blood. Oxygen rich blood is then pumped to cells throughout the body. The circulating blood collects carbon dioxide and transports the CO2 back to the lungs where it gets eliminated by exhalation.

Healthy Microbiota

Healthy microbiota is said to act like a gatekeeper that stops respiratory pathogens from settling and can also aid in the maturation and maintenance of homeostasis of respiratory physiology and immunity. A collection of specialized resident bacterial, viral, and fungal is found in the upper respiratory tract and likely stops potential pathogens from invading and spreading to the lungs. Lung microbiome primarily originates in the upper respiratory tract. The microbiome in healthy people contain Transient microorganisms, they are formed by the immigration and destruction balance of microbial. The most common bacteria in the nasal passages and sinuses include Staphylococcus Epidermidis, Viridans group Streptococci, Corynebacterium Spp., Propioni Bacterium Spp., & Haemophilus Spp. The pharynx can be the home to pathogenic strains such as Streptococcus, Haemophilus, and Neisseria.

Mycobacterium

There are different bacteria that causes different infections of the respiratory system. One bacterium that is known to cause a respiratory infection is mycobacterium. Mycobacterium is a bacterium that comes from the family mycobateriacae. Mycobacteria look like fungal mycelium because of its slender rod-shaped branching filamentous form. The greek prefix for myco in mycobacteria means “fungus”. The reasoning for mycobacterium to be a fungus like bacteria is because when in liquid mycobacteria forms a mold like pellicle.

Colonies of Mycobacteria

Mycobacteria can be killed at 60°C within 15-20 mins and also can be killed by direct exposure to sunlight for 2 hours, which is why mycobacteria is not resistant to heat. Mycobacterium bind to parasites or live on broken down organic materials. Mycobacteria can be found in different environments such as water, soil, free living farms, and in disease infected tissue of animals. Robert Koch discovered Mycobacterium Tuberculosis in 1882, in which this is the bacteria that causes a respiratory infection known as Tuberculosis (TB). Mycobacterium tuberculosis contains a substance known as mycolic acid which gives the cell a waxy coat. This waxy coating makes the cell be impermeable to gram staining which makes the cell be neither gram positive nor gram negative. Cells such as mycobacterium, are said to be acid-fast bacteria because of their impermeability to specific dyes and stains.

Tuberculosis is a disease in the respiratory system that primarily affects a person’s lungs. Although anyone can catch tuberculosis, there are many risk factors that can increase the chances of becoming infected with this disease. The risk factors that can increase the chances of becoming infected include weakened immune system, travelling or living in certain areas, poverty and substance use, and where you work (health care). Tuberculosis is contagious, unless a person has been treated for at least 2 weeks with the right drug in which they are then no longer contagious. This disease spreads from a contagious person with the disease to a person without the disease by coughing, speaking, sneezing, laughing, and singing through inhalation of droplets that spread in the air.

When tuberculosis goes untreated the infection can spread through the blood and cause complications such as spinal pain, joint damage, meningitis, liver or kidney problems, and heart disorders. There are two types of TB: primary tuberculosis and secondary tuberculosis. Primary tuberculosis is the first infection and usually found in children. Tis type makes up a ghon complex by subpleural granuloma and granulomatous hilar lymph node infection coming together. Secondary tuberculosis is usually the reactivation of the first infection and usually found in adults, likely when their health declines.

There are 2 stages of TB and these are Latent TB and Active TB. Latent TB s when the infection remains in your body in its inactive form. In this stage there are no symptoms and is not contagious, but without treatment it can become active and contagious. In the active stage of TB you have symptoms and are contagious.

Signs and symptoms of TB include:

• Coughing for 3+ weeks
• Coughing up blood
• Chest pain
• pain with breathing
• Weight loss
• Fatigue
• Night sweats
• chills and loss of appetite

Diagnosing Tuberculosis

Diagnosis of tuberculosis can be done in a few different ways. A doctor will check your lymph nodes for swelling, listen to your lungs with stethoscope while you breathe, blood test, and a tb skin test. A blood test is known as interon gamma release assays, and it tests a person’s response to tb antigens. If the test comes back positive, it means there has been b germs resent and further testing may be needed to and out whether its active or not.

The TB skin test the most common type of TB testing. Tis test is known as the mantoux test and requires to visits. The mantoux test occurs by injecting an inactive TB protein containing fluid called tuberculin under the skin on the forearm. You then wait 2-3 days before going back to the doctor to get the results. If the injection site is raised, has a hard bump or swelled, then your results are positive. If you have no reaction their results are negative.

References

1. http://textbookofbacteriology.net/tuberculosis.html
2. https://www.nature.com/articles/nrmicro.2017.14
3. https://courses.lumenlearning.com/microbiology/chapter/anatomy-and-normal-microbiota-of-the-respiratory-tract/
4. https://www.mayoclinic.org/diseases-conditions/tuberculosis/symptoms-causes/syc-20351250
5. https://webpath.med.utah.edu/TUTORIAL/MTB/MTB.html
6. http://www.webmd.com/lung/test-tuberculosis#2
7. http://www.medicalnewstoday.com/articles/8856.php#symptoms