Category: Epidemiology

Introduction

Remote Sensing has brought so many advances to many different scientific disciplines, including the study of epidemiology. For as long as life has been on the Earth, disease has always been factor in the success of any species. Pandemics throughout the history of time have devastated the populations of both animals and humans. This paper looks to explore the use of remote sensing in the fight against the spread of disease in human populations that threaten our way of life on a daily basis.

Main Body

Scientists are adopting new remote sensing (RS) techniques to study a variety of vector borne diseases. Environmental data collected from satellites such as temperature, sea surface temperatures, land cover, vegetation density and vector density are being used to characterize vector habitats. The use of RS to map vector borne diseases has ‘evolved significantly’ over the past 25 years (Kalluri, 2007). Sadly, until the 20th century vector borne diseases were responsible for more human deaths that all other causes (Kalluri, 2007). Interesting much of the focus in the study of disease is on the natural cycles of life, but there are many other factors that influence the spread of diseases, that include floods and other natural disasters. RS may be able to offer more answers to health scientists and epidemiologists in the field of diseases caused by disasters aside from the research that is already being conducted.

The beginnings of spatial analysis occurred more than 100 years prior to any satellite being launched. In September of 1854 a cholera outbreak occurred in the SoHo district of London. At that time a medical doctor, John Snow, was fairly convinced the disease was caused by a water borne pathogen, even though his theory went against popular belief. To further his theory, Dr. Snow created a map of the area that included the location of public water pumps as well was the concentrations of cholera fatalities. There were 521 cholera deaths within 250 yards of the Broad Street pump. The map confirmed Dr. Snow’s theory that the Broad Street pump was the culprit of the outbreak. In response, the handle of the pump was broken by skeptical local authorities and the outbreak quickly subsided. (David A. Vaccari, 2006)

Although this example is not a study in RS, it does demonstrate the importance of analyzing data spatially in the fight against disease. In an article published in the National Institute of Health’s Library of Medicine, the techniques of Remote Sensing and Epidemiology ‘have the potential to revolutionize the discipline of epidemiology and its application in human health’. The article explains in great detail the definition of remote sensing, electromagnetic radiation, atmospheric transmission, spectral response, active and passive remote sensing, as well as many other parameters of remote sensing. But mostly the author also explains how the applications of remote sensing can be applied to the study of disease. Such as the use of spectral vegetation indices with reference to chlorophyll and carotenoid pigments, land surface temperature indices and atmospheric moisture indices (Hay, 2000). Interestingly the article, which was published in 2011, seemed to infer that the combination of remote sensing in the field of epidemiology is a potential application, even though studies have been published as early as 1970. Others share Hay’s enthusiasm as seen in an article in the American Journal of Epidemiology where the author describes the use of aerial photography and other remote sensing techniques as ‘New Eyes for Epidemiologists’ (Cline, 1970).

Although the use of RS appears to be a useful tool in the study of human health, the study is not without it’s critics, as explained in a 2007 Health & Place journal article. The authors explain that much of the research conducted invloves the use of pre-processed spatial data and low cost images, which limits the adaptability of the data for biological uses. Other criticicms included extrapolating local data to regional areas and the lack of supported field work. The problems where are further exacerbated by the lack of acknowledgemet of these limitations in many of the papers cited in the article.

Though the criticisms of the use of remote sensing and epidemiology may be justified, the research that has been conducted would certainly have value. This has been demonstrated in several studies that use the data from environmentally remote sensed images in the study of disease. This is demonstrated in a study involving the creation of software used to combine RS data with earth science data profiled in the journal ‘Environmental Modelling & Software’ (Liu Y, 2014). The software titled ‘EASTWeb’ is an open source application, that requires client input that automatically connects to earth science data archives and processes and summarizes remote sensing data sets. The user inputs a time and a place which is in turn integrated with the data sets. The goal of the software is to predict high risk factors and for the support of early warning systems specifically for malaria and West Nile outbreaks in many parts of the world, including the United States (West Nile) and Ethiopia (malaria). The result is a ‘high level architecture’ program.

The RS components that are implemented for the software include MODIS, TRMM and ETo data, which are used to create environmental indices that are used to calculate a variety of metrics. Based on the results, a statistical model is developed for use to forecast and respond to threats to human health by the specific vector borne diseases mentioned above.

Limitations to the software, according to the authors of the article, are the large volumes of data that are necessary and need to be stored and processed on local computer systems. The software is also highly specialized to respond only to threats specifically from malaria and West Nile. Other software programs used in epidemiology are more generalized, which make those programs more adaptable. Even so, there is value in specialization since diseases and factors affecting their spread can be varying. The future of the software may include integrating other forecasts, such as epidemiological and entomological data, which should increase their effectiveness.

Another example of the RS and human health research is being done is by the European Space Agency, Copernicus. The space agency was working to minimize the exposure and increase the response to the outbreaks of Ebola that occurred in 2014. Parameters such as water bodies, wind or dust and land cover were and continue to be monitored to aid in the prevention and timely response to outbreaks in areas prone to epidemics. The sentinel-2 is a mission that has been used to achieve these directives. The mission comprises of twin polar-orbiting satellites in the same orbit, phased at 180° to each other. It has a wide swath width and a high revisit time of either 10 days at the equator with one satellite or five days with two satellites. The mission monitors changes to vegetation in the growing season. The coverage limits are from latitudes 56° south and 84° north, which would include the study area of Kwendin, Liberia. An article in the ‘Copernicus’ journal outlines a particular study concerning the fruit bat, which is a vector of Ebola (Tracing the Outbreak of Ebola, 2014). The following image details the land cover, such as roads and settlements within areas of dense tropical forests and oil palm cultivations that support fruit bat populations.

When viewing the aerial image and highlighting the proximity of the environmental factors to populations, high risk areas are easily identified. A similar study was conducted in Tanzania and the outbreak of disease involving the nematode, Ascaris lumbricoides. This infectious agent is mainly prevalent in the tropics and affects one-quarter of the world’s population. It can cause respiratory and gastrointestinal problems.

The remote sensing data for this was obtained from ‘The Shuttle Radar Topography Mission’ (Farr, 2007), which employed two synthetic aperature radars with a C band (5.6 cm) radar and a X band (3.1 cm) radar in the shuttle payload bay, as well as secondary C and X band attenas in an 60 meter mast, used to obtain digital elevation models.

The elevation data obtained from the Shuttle Radar Topography mission was used to calculate slope, which contributed to climatic conditions that contributed to the prevalence of disease cause by the nematode (Schule, 2014). Conclusions from the study attributed the main environmental factors in the spread of the disease to rainfall, land surface day temperatures and vegetation density (positive correlation).

Human health is not only affected by vector borne diseases, but often by the methods used to eliminate the vectors. This is demonstrated in a study used to link pesticides to human health (VoPham T., 2015). The study used Landsat images captured since 1972, and compared them to rarely updated land use crop data to reconstruct past exposure to specific pesticides. The ultimate goal was to estimate pesticide exposure based on crop fields near residences. Supervised classification of was implemented to classify various types of crops that would satisfy the four pieces of information necessary to the study; Landsat images, ground truth, pesticide application data and geocoded locations. The land use classes were identified by a sample of 1990 NDVI signatures and patterns.

The particular usefulness of using RS data as compared to GIS data is based on informational input involving the changes occurring in planted crops that may not be reported. Changes in landscape features such as crop rotations and land use conversions would be captured by RS sensors such as Landsat. The data captured would ultimately have to be validated in an Accuracy Assessment, as compared to Land Use surveys.

The Center for Disease Control (CDC) also recognizes the importance of RS in the field of epidemiology. An article published in the ‘Emerging Infectious Disease’ Journal highlights many studies that are being conducted, such as cholera in Bangladesh and Lyme disease the northeastern United States. Interestingly, the Lyme disease study used local, municipal data from veterinarians to measure the risk to human health, based on the assumption dogs are more likely to be bitten by ticks near their owner’s property. The Landsat thematic mapper measured and derived indices of vegetation greenness and wetness. The deer population, in relation to forest size and density was also a factor and was recorded. Ultimately it was determined that greenness and wetness were positively correlated with tick abundance (Beck, 2000).

The second study highlighted in the article concerns outbreaks or cholera in Bangladesh. Similar to another study discussed in class, this research correlated sea surface temperature (SST) to phytoplankton. Which concludes as SST temperatures increase, phytoplankton populations increase and cholera outbreaks increase. Positively the CDC looks to the future of RS by stating; “In the next 15 years, new sensors will provide valuable data for studies of infectious diseases similar to the ones described here. For Lyme disease, new sensors could provide similar information about ecotones, human settlement patterns, or forests. These sensors include ARIES-1, scheduled for launch by Australia; CCD and IR/MSS sensors onboard CBERS, launched by China and Brazil in late 1999; Ikonos, a commercial satellite with 4-m spatial resolution; LISS III, onboard the orbiting Indian IRS-1C and -1D satellites; and ASTER, onboard the recently launched Terra satellite. Information from these sensors could also be used to address other vector-borne diseases, such as malaria, schistosomiasis, trypanosomiasis, and hantavirus, whose patterns are likewise influenced by environmental variables.’ (Beck, 2000).

Much of the focus in the study of RS and epidemiology involves precipitation and vegetation density. Recently health scientists have made the connection between meningitis and dust. This is demonstrated in a study by The International Research Institute for Climate and Society in Sahel, Africa (Cuevas, 2011). The mineral dust may enhance meningococcal by damaging the mucous barrier in the epithelial lining in the upper respiratory tract aiding bacterial penetration. A more controversial theory suggests that the dust particles may actually be a carrier for the bacteria. The NMMB/BSC dust model was used in the study.

Remote sensing techniques were aided by providing total column dust observations, although it cannot be assumed that dust near the ground actually affect the population. Even so, the focus of the study was primarily on dust, which did correlate to an increased incident of meningitis.

It is worth reiterating that although the future of RS is promising, limitations of the data collected should be acknowledged and minimized as profiled in an article in Environmental Health Perspectives (Seltenrich, 2014). The author acknowledges the great promise in satellite data in projecting the outbreaks of infectious disease, but cautions that ‘satellite imagery does not provide a complete or perfectly reliable picture of what’s happening on the surface and should be verified by and blended with ground-sensed data’.

Conclusion

The marriage between RS and Epidemiology has only begun to hit its stride. While the use of RS has been used since the 1970s, there are still many limitations, primarily based on a lack of focus specifically relating to the study of disease and human health. Programs and software that are currently utilized were not designed for epidemiology, which may present challenges. Fortunately, many of the vector borne diseases have a strong correlation with environmental conditions, which is a field of study that is very compatible with RS and by extension epidemiology. It is worth noting that none of the studies were able to rely upon RS exclusively. Even though RS has been a useful tool in the study of human health, all of the studies required the collection of other data from other disciplines to be useful. Whether it was a confirmation from ground truth data, health samples or municipal data, no one has been able to look at an image created from a sensor and be able to ascertain any kind of risk or response to human or animal health.

Ultimately, for RS to be used in the mainstream study of epidemiology, many factors need to be improved. Factors such as higher spatial and spectral resolutions, increased satellite coverage, cost management and increased availability of data from new sensors should bring RS to the forefront in the surveillance and management of disease control.

Epidemiology is the study of the spread and causes of health-related events such as disease, and the application of this study to the control the disease. It is a tool that public health authorities use to determine the cause of a disease and affected populations. Epidemiology can also assist in developing strategies to improve public health and evaluate the effectiveness of strategies in place to treat the disease. It is practiced through studies in which analysis data is performed allowing for the identification of pattern and trends in the incidence, prevalence and mortality rate of the disease. This information can is used to identify areas and ways in which the overall health of the population can be improved. An instance of this of this is seen in the epidemiology study of Skin Cancer in Nambour, Queensland or epidemiology study in the Sun Smart program.

The epidemiology study of skin cancer tested the hypothesis that the incidence of skin cancers specifically Basal cell carcinoma and Squamous cell carcinoma (skin cancers) in outdoor workers is greater than that in indoor workers. This study was carried out between 1986 and 1992 with a random sample of 3,000 individuals aged 20-69 years listed on the electoral roll as residents of Nambour, Queensland, and invited to participate in a skin cancer survey. The survey was conducted by experienced dermatologists examining all participants for prevalent skin cancers on the head, neck, and upper limbs, as baseline for the study and prevalence rate of BCC and SCC. During clinical examination the survey also recorded the number and location of skin cancers, hair colour, number of raised and flat nevi on the hands and arms, and signs of solar skin. Each participant was asked about present and past occupations (whether outdoors, indoors, or a mixture of indoors and outdoors), typical outdoor recreational exposure, usual number of hours spent outdoors, number of painful sunburns experienced in their lifetime, sun safety routine, general lifestyle and parents’ countries of origin. Information about skin cancers treated between December 1987 and August 1992 was obtained through an additional postal survey. Incident skin cancers that were diagnosed clinically at the 1992 survey were biopsied for the diagnosis by a single pathologist, who had also examined all biopsies of suspected skin cancers diagnosed in the 1986 survey. Incidence rates of BBC and SCC were adjusted by age, degree of solar skin damage, skin colour, and sun exposure adjusted using a scientifically approved model. Age-adjusted skin cancer incidence rates were estimated to be 2,528 per 100,000 person among males and 1,676 per 100,000 among females over the 6 years of follow-up.

However, it showed there was no statistically significant correlation between outdoor occupation and the incidence of BCC and SCC skin cancer. Researchers stated that may have been the result of outdoor workers practicing sun safety when exposed to the sun. It also showed that there was a correlation of increase presents of solar keratosis (sun damage) to higher incidence rates of BCC and SCC cancer. As, subjects with no keratoses have an incidence percentage of BCC and SCC of 1.00%, followed by subjects with 1 to 10 keratoses at 1.62% and the highest incidence percentage of 2.18% with subjects of 11 or more keratoses. This information led public health authorities such as by Cancer Council Victoria and the Victorian Health Promotion Foundation to create and continue funding campaign such as the SunSmart program. The SunSmart program mission is to reduce skin cancer incidence, morbidity and mortality through a targeted prevention, with the message of “Slip! Slop! Slap! Seek! Slide!”. Epidemiology studies like “SunSmart Evaluation Study of 1992” have also monitor are the SunSmart program, leading to the conclusion that while skin cancer incidence in Victoria continues to rise, there are now falling incidence rates in men and women younger than 40 years, consistent with a positive effect of the SunSmart program on behaviour change. SunSmart Evaluation Study have found that target audiences needed to be widened to from young children to adolescents. Thus, hard-hitting messages and graphic prompts were incorporated into the media campaign, designed to shock people into action to target older audiences.

In conclusion, epidemiology is paramount instrument, that provides useful information that can be used to identify the cause of a disease and design strategies to cope with diseases within the population. For example, the epidemiology study of Skin Cancer in Nambour, which identified that sun damage can lead to skin cancer. It is also used by public health authorities to evaluate and improve strategies that are already in place. This is seen in the SunSmart Evaluation Study of 1992, where the SunSmart program was monitored, and issues such as target audience were identified and improved.

The health issues are known to take place when metabolism of body is altered or is subjected to failure due to the pathogen or pollutant that are considered as the disease. On the other hand, the epidemic disease is referred to as wide spread of the disease that occurs in other regions than that of the expected area at the given time period.

Overview of key health problems

Cholera

Cholera is regarded as the infectious disease, which results in the severe diarrhea, leading to the dehydration and death in some cases. This occurs by consumption of contaminated food with the bacterium known as Vibrio cholerae.

Nature

It is generally termed as the acute enteric disease as per the variation in severity. Most of the infections are regarded as asymptomatic. In the mild cases, the diarrhoea takes place without any further symptoms. The disease of cholera has been observed to pandemic in the initial cases in past 200 years. In addition, the cholera has also been documented in the epidemic form, which was widespread in the areas of South America as well as Yemen.

Extent

The impact of cholera has been identified to be highly severe among the human population, with the estimation of about three to five million cases of cholera and about 100000-120000 death tolls worldwide.

Why is it a public health issue

In the year of 2016, the report of 132,121 cases of cholera and about 2420 deaths has been presented to WHO globally. The outbreaks have continued to make an impact on the several countries. Overall, about 54% cases have been observed from Africa, 13% reported from Asia and about 32% reported from Hispaniola. With all these, cholera sustains the position of major public health issue that primary continues to affect populations of developing world without process accessibility of sanitation resources or water.

Influenza

It is referred to as the respiratory illness, which is contagious and is caused by the influenza virus. It can lead to mild and severe illnesses and can even lead to death in few cases.

Nature

It has been characterized by the annual and seasonal epidemics followed by the pandemic and sporadic outbreaks that involve the influenza strains belonging to the zoonotic origin.

Extent

As per the estimation of WHO, the annual epidemics has resulted in approximately one billion infections, including the three to five million cases of the severe illness.

Issues on identifying the health problems or population affected and data sources and evidence gathering

The issues have been observed in the identification of health populations, which involve the assessment of the risk factors, effectiveness of the vaccine and patterns related to the utilization of the healthcare. These include the challenges, which involve the biases that are in association with chosen participants of the population, difficulty in the adjustment for the confounders as well as restricted specificity due to the reliance on the syndromic definitions for the disease limits (Wójcik, Chunara and Johansson, 2014).

Epidemiological methods and approach

The epidemiological methods are necessary for the disease surveillance in identifying the significance of the hazards. Besides that, the methods are also effective in identifying the risk factors that are crucial in evaluating the public health issues. The epidemiological method approach used in this context of article is the participatory surveillance that refers to the participation of community in the disease surveillance. In this research method, the public engagement is transformed with the help of participatory surveillance systems, which enables public to report on the diseases through the internet (Wójcik, Chunara and Johansson, 2014).

Summary of data on distribution of the health issue according to population characteristics

Age

It has been identified that there has been about 11 million cases of cholera that occurs globally among the children belonging to the age group of 5 years. However, it also causes severe impact among the adolescents and adults along with high mortality rate in all the age groups (World Health Organization, 2018).

Sex

The girls and the women have developed higher risk of incidence regarding the cholera due to their high exposure to household activities such as handling of the contaminated water and raw food. Thus, there has been excess burden of disease among school going girls and women (Unicef.org, 2017). It has been identified that the young boys have a tendency of higher rate of incidence among the young children and the infants, which is reversed among adults and older children, where higher rate is for females.

Ethnic groups

Cholera has been a widespread disease, which is evidently observed on the developing countries as well as catastrophically on the content of Africa, which has recorded about 2.4 million cholera cases and about 120,000 deaths in few decades (Unicef.org, 2017).

Environmental attributes

Geographical

Cholera has been evidently widespread on the African continent that has contributed to the epidemic spread. In addition to that, the epidemic influence of cholera has also been witnessed in South America (OSes, Duker and Stein, 2016).

Socio-economic

The risk factors of the known cholera population level include the lack of the development, poverty along with the high population density. The other aspects such as the poor sanitation, housing, and lack of proper water supplies and synergy of the poverty majorly contributed in enhancing the exposure to the cholera pathogen (World Health Organization, 2018).

Education

It has been observed that the lack of education and exposure to the knowledge is mainly associated with higher incidence rate of cholera among population. Unicef.org (2017) have stated that low status of education acts as a crucial risk factor of the disease in the areas of Bangladesh (OSes, Duker and Stein, 2016).

Temporal variation

The temporal variation of the epidemic cholera is linked with the forces such as the temperature of sea surface and patterns of rainfall. Studies have observed there has been environmental associations with the pathogen that involves depth, water temperature and depth, which contributes in the secular and seasonal trends in outbreaks (OSes, Duker and Stein, 2016).

Population distribution

Age: The people who suffer from the greater risk of evidence includes the pregnant women, the children under fifty-nine months and the elderly individuals who are more than 65 years old (Who.int, 2019).

Sex: It has been observed that the reported infection incidence with the seasonal influenza is relatively prevalent in the developing countries such as Spain and the USA, where the rate of affected males is slightly higher than that of females (Who.int, 2019).

Ethnicity: The influenza is highly prevalent across the globe, with the annual attack rate of about 5-10% in the adults and about 30% among the children, majorly affecting people belonging to white ethnicity and non-Hispanic individuals (Who.int, 2019).

Socio-economic and demographic distribution

Geographical: In the temperate regions, the influenza is referred to as the seasonal disease that mainly occurs in the months of winter and affects northern hemisphere from the month of November to April as well as southern hemisphere from month of April to September. In the tropical regions, there is an absence of clear seasonal pattern and the influenza circulation is prevalent yearly typically at peak during the monsoon period (Apps.who.int, 2019).

Socio-economic conditions and education: It has been found that the poor consequences from the seasonal influenza involve, involve the obesity and diabetes. In addition, diabetes mellitus is another risk factor for the severe influenza with the potential association with the increased morbidity. Therefore, it can be said that the individuals belonging to the low socio-economic condition are at higher incidence rate of influenza (Apps.who.int, 2019).

Strengths and limitation of article

Strengths

The participatory surveillance research method comprises of various strengths, one of which includes the easier method of the collection of the data, as compared to the traditional surveillance research method identified in the previous literature. The new surveillance research approach comprises of the convenient internet based form which exhibits increased accessibility from various locations (Wójcik, Chunara and Johansson, 2014). This in turn, is identified to be highly effective in decreasing the costs that are associated with the operation of the participatory surveillance system. Apart from that, scalability is referred to as another technical strength that is linked with the new surveillance research approach that has been identified in the article.

Limitations

The research method that has been used is the participatory surveillance system, comprises of certain limitations, which involves the population of the participants which shall not be representative of general population. The majority of the participants that have been taken into consideration in the studies comprise of women. However, the elderly individuals and children are likely to make use of the internet. In addition, it also comprises of limitation regarding the collection of the data from the participants. Thus, it has been found that amount of the resources such as the computation, finances, time and personnel, which are required to be expanded is minimal as compared to the traditional method approach (Wójcik, Chunara and Johansson, 2014).

Policies and their impacts on the public health issues

The treatment related benefits are considered to be private, the spillovers might interpret that it is carried out in the personal interests of the rich countries for paying the AV related treatments in the poor countries. The major cost effective policy that has been identified for the rich countries is the donation of the doses to source of outbreak in the country. However, it has also been identified that the donation of the doses to the poor countries in the proportion of the population, might also be termed as cost effective. These are highly dependent on flu strain transmissibility, antiviral efficacy in the reduction of the transmissibility along with the proportions of the infections, which can be treated and identified. The policy focuses on the mitigation of spread of the flu with the administration of the antiviral for the individuals with the symptomatic infections. In absence of the international cooperation’s, it has been assumed that there is a variation in the antiviral stockpiles along with per capita income, where the poor countries are deprived of the antiviral stockpiles. In this regard, the rich countries are expected to pay for the stockpiles, which are then distributed to the poor countries. This is then, judged by the success of the control strategy in accordance with the rate of the infected population at the year end. The influence of the policy response of in form of the influenza treatment is dependent on size of the treatment externalities, which are identified to be large if the pandemic occurs in source country. In the case where the pandemic spreads through the air, the externalities comprise of a strong association with the anti-viral treatments that are smaller (Hirve, 2016). This means that the treatment of the infectious people in the residing country shall lead to decline in the local attack rate. It has always been evident from the study that the wealthy countries are expected to carry out purchase and distribution of the anti-virus doses in outbreak country. In other case, the private marginal benefits for treating the local patients exceed the marginal benefits from the donation of the doses that are being outsourced. However, if the prosperous countries are able to retain the stockpile of the antiviral drugs, that are sufficient for treating the domestic cases. This may lead to the increase of the welfare by the paying of for purchase as well as distribution of the additional doses to outbreak country. The donation of the antivirus to the outbreak country has led to the reduction of the number of the influenza related cases in the rich countries by around 4.76 million influenza cases after one year. This policy donation has been regarded as the wealth enhancing aspect for the wealthy countries at 0% case of the fatality rate.

The policies related to the identified health issue of cholera involves the case management policy, which makes use of the effective treatment in residing in the prompt rehydration through administration of the ORS (oral rehydration salts) or the intravenous fluids, as per the case severity. It has been observed that about 80% of the patients could be treated in an adequate manner with the ORS administration. The dehydrated patients are required to be treated through administration of the intravenous fluids along with the appropriate dosage of the antibiotics, which is to be provided in the serious cases. In addition to that, the cholera has been widely referred as the water-borne infection, which can take place due to poor sanitation, hygiene along with the consumption of the contaminated water and food (Wójcik, Chunara and Johansson, 2014). Thereby, it has been observed that the implementation of the HWT system intervention is not suitable for the outbreak of the epidemic disease. Thus, the policy response has been exclusively focused on the WASH intervention policy that further states that the water and sanitation supply for the improved hygiene has yielded higher rate of decline in the disease in comparison to those for the water quality (Ali and Sack, 2015). This has been facilitated with by execution of the water and sanitation policy related interventions. Further research conducted in the HWT studies have been considered to have combined decrease in the diarrhoeal disease by about 35%, thus contributing to the improvement of the access to the sanitation and water. The policy has also provided an exposure to the implications regarding the maintenance of the hygiene, improvement in quality of the water, which in turn, creates a positive impact on the reduction of the incidence rate of diarrhoea. From the recent reviews, it has been identified that there has been shortage of the accurate evidence for the intervention policy of WASH in case of emergencies. These interventions are found to have significant impact in the reduction of the diarrhea among the adults along with the decline in the rate of absenteeism among the children in the school. The impact related to the WASH has been documented in a proper manner, which has signified considerable evidence in the reduction of the disease of cholera by the implementation of the WASH intervention policy.

Recommendations

The participatory epidemiology has been referred to as the application of the participatory methods in the disease surveillance as well as the epidemiological research approaches. It has been considered as the proven technique that is effective in overcoming the various limitations regarding the epidemiological conventional methods, which in turn, is crucial in solving number of the human public health surveillance and the research issues (Jost CC, 2017). The approach has been developed in the small scale, then further applied to the major control effects regarding the epidemic disease. The research approach has adopted the participatory epidemiology as the surveillance tool in carrying out the further research. In addition, this approach has been subsequently applied in both the urban and rural settings in the regions of Asia and Africa, for the diarrhoea related diseases along with the highly pathogenic influenza. Apart from that, the participatory disease surveillance has been identified in making significant contribution in controlling of the epidemiology related disease risks. Thus, the authorities are required to review principle applications related to the applications regarding the participatory epidemiology followed by the implications related to the field applications. This in turn, the research further needs to carry examinations regarding the future challenges, considering the new areas for the research. Another type of the gathering of the data that should be taken into consideration is the analysis of the collection of the data. All the epidemiological data regarding the cholera in the epidemic as well as the sporadic cases is to be obtained from the registered documents that are in accordance with the Center for Disease Control and Prevention of Ministry of Health and the education, that is based on the WHO and CDC definition. This is to be facilitated with the analysis of the data that has been recorded on the systems. Last but not the least, the descriptive data shall be applied for the expression of the data (Jost CC, 2017).

Either the guidelines related to the cholera shall be able to incorporate the necessary standards, international or national that has been outlined by World Health Organization such as the water quality, case management as well as the surveillance. Based upon national context, the authorities are required to support government in the development of the intersectoral guidelines of cholera that covers the sectors related to health, protection, education and communication as well as dissemination and training the personnel. The policy related to the WASH intervention strategy is found to be highly effective in the improvement in the lifestyles of the individual population. Thus, the data on the facility functioning as well as usage needs to be gathered following the implementation. Further, the research has been required for the evaluation of the intervention along with the delivery method in the outbreak setting. The research shall be focusing on the cholera, along with the external additional benefits that are to be gained in reducing the diarrhoeal diseases. In addition to that, WASH related interventions are required to seek guidance as well as leadership, which in turn, is crucial in the evaluation of health impact of the activities. Apart from that, the policy needs to be implemented, which shall be emphasizing on the education of the public regarding the outbreak of the epidemic diseases and evaluate an effective planning for taking the protective measures for avoiding such diseases. These shall be including the cooking of the food in a thorough manner, washing hands properly, taking ORS in order to avoid the risks related to diarrhoea and seeking immediate help for the diarrheal illness.

References

1. Ali, M., Nelson, A.R., Lopez, A.L. and Sack, D.A., 2015. Updated global burden of cholera in endemic countries. PLoS neglected tropical diseases, 9(6), p.e0003832.
2. Apps.who.int. (2019). Sex, gender and influenza. [online] Available at: https://apps.who.int/iris/bitstream/handle/10665/44401/9789241500111_eng.pdf%3Bjsessionid=F157499D0E35E37B66FDA8201AD320D4?sequence=1 [Accessed 23 Apr. 2019].
3. Friedrich, M.J., 2016. Cell Phone Data Help Investigators Understand Cholera Spread. Jama, 316(3), pp.259-259.
4. Hirve, S., Lambach, P., Paget, J., Vandemaele, K., Fitzner, J. and Zhang, W., 2016. Seasonal influenza vaccine policy, use and effectiveness in the tropics and subtropics–a systematic literature review. Influenza and other respiratory viruses, 10(4), pp.254-267.
5. Jost CC, e. (2017). Participatory epidemiology in disease surveillance and research. – PubMed – NCBI. [online] Ncbi.nlm.nih.gov. Available at: https://www.ncbi.nlm.nih.gov/pubmed/18293603 [Accessed 23 Apr. 2019].
6. Kliner, M., Keenan, A., Sinclair, D., Ghebrehewet, S. and Garner, P., 2016. Influenza vaccination for healthcare workers in the UK: appraisal of systematic reviews and policy options. BMJ open, 6(9), p.e012149.
7. Ortiz, J.R. and Hombach, J., 2018. Announcing the publication of the WHO immunological basis for immunization series module on influenza vaccines. Vaccine, 36(37), pp.5504-5505.
8. OSes, F., Duker, A. and Stein, A. (2016). Cholera and Spatial Epidemiology. [online] Pdfs.semanticscholar.org. Available at: https://pdfs.semanticscholar.org/6bfe/9b11de2651d1f2c1144e47dbb3a14b156a68.pdf [Accessed 23 Apr. 2019].
9. Piarroux, R. and Frerichs, R.R., 2015. Cholera and blame in Haiti. The Lancet Infectious Diseases, 15(12), pp.1380-1381.
10. Tsuzuki, S., 2019. Economic consequences of Japanese schools’ recovery certificate policy for seasonal influenza. BMC public health, 19(1), p.280.
11. Unicef.org. (2017). [online] Available at: https://www.unicef.org/cholera/Chapter_8_case_management/29_Haiti_UNICEF_Briefing_Note_Gender_Cholera.pdf [Accessed 23 Apr. 2019].
12. Who.int. (2019). Influenza (Seasonal). [online] Available at: https://www.who.int/news-room/fact-sheets/detail/influenza-(seasonal) [Accessed 23 Apr. 2019].
13. Who.int. (2019). WHO | Seasonal influenza. [online] Available at: https://www.who.int/ith/diseases/influenza_seasonal/en/ [Accessed 23 Apr. 2019].
14. Wójcik, O.P., Brownstein, J.S., Chunara, R. and Johansson, M.A., 2014. Public health for the people: participatory infectious disease surveillance in the digital age. Emerging themes in epidemiology, 11(1), p.7.
15. World Health Organization. (2018). Cholera. [online] Available at: https://www.who.int/gho/epidemic_diseases/cholera/en/ [Accessed 23 Apr. 2019].

Introduction

Social structures or networks such as access to education, employment, inclusion in society and so on are important prerequisites in shaping the health of people in any given circumstances. The extent to which we incorporate these factors coupled with biological agents explains why disease are produced (Berkman, Kawachi, & Glymour, 2014). For example people with good education have access to better quality health care and are well integrated in societies thus are rarely affected with mental health problems. This has been seen to be a major problem in low income countries where mental health issues are often being neglected on a wider scale (Sankoh, Sevalie, & Weston, 2018). These are guided by some of the theories which are described below;

The psychosocial theory explains the different level of insusceptibility exerted by individuals in societies to become more vulnerable in getting a disease as a result of their exposure or otherwise (Krieger, 2001).It is apparent therefore in this context to understand the most important mechanisms underlying the development of such disease. Indeed one can argue that the differences in which people are inclusive in or isolated in societies also plays a central role in defining who gets which disease at any point in time and space (Berkman et al. 2014). However, according to Oakes and Kaufman (2006), individuals with mental health conditions are improved if they receive social support from family members and friends in societies in which they live. This explains why people with mental health problems needs to be integrated in societies in order to improve their health outcomes.

Social production of disease theory asserts the implication of the unequal distribution of resources to individuals in societies leading to the increasing gap in the socio economic status of people (Krieger, 2001). It is however important to put into consideration that individuals who lack good education, employment or better income are always inevitable to have poor health outcomes as compared to their counterparts because of their involvement in multiple poor behaviors (Berkman et al. 2014). This is a crucial momentum as it may construct a vicious cycle of poverty from one generation to the other and the extent to which this varies in the society should not be underestimated. It is also easier for biological agents to enter and cause diseases in these group of people because of their weak immunity as a result of excessive exposure to hazards.

Eco-social theory depicts the outcome of individuals health when they are exposed to multiple factors in the environment in which they live coupled with other social factors (Berkman et al. 2014). It could be understood that the exposure to disease causing organisms can actually vary among people in the same geographical location which is largely connected to the level of support one is privileged to have. The response to each of these biological forces within the body may differ significantly even where as we are all confined within the same environment (Krieger, 2001). According to Koenen (2014), mental illness is predominantly visible among adults who in some cases were in their early life (fetal development) exposed to difficult moments. This tells us why it is important to provide substantial protection to women during pregnancy in order to prevent such an undesirable health outcomes.

In conclusion, the manner in which disease occurs among people is multifactorial. In addition, social structures are not equally distributed within the population and therefore have an effect on the population as a whole. Since disease arises as a result of cumulative exposures to both past and present biological and environmental agents (Kuh, Ben-Shlomo, Lynch, Hallqvist, & Power, 2003),it is therefore imperative to control how and to what degree we are exposed to such conditions in order to improve our health especially among mentally ill people in our societies.

References

1. Berkman, L. F., Kawachi, I., & Glymour, M. (2014). Social Epidemiology. New York, UNITED STATES: Oxford University Press USA – OSO.
2. Krieger, N. (2001). A glossary for social epidemiology. Journal of Epidemiology and Community Health, 55(10), 693. doi:10.1136/jech.55.10.693
3. Koenen, K. C. (2014). A life course approach to mental disorders. Koenen, Koenen.
4. Kuh, D., Ben-Shlomo, Y., Lynch, J., Hallqvist, J., & Power, C. (2003). Life course epidemiology. Journal of Epidemiology and Community Health, 57(10), 778-783. doi:10.1136/jech.57.10.778
5. Oakes, J. M., & Kaufman, J. S. (2006). Methods in Social Epidemiology. Hoboken, UNITED STATES: John Wiley & Sons, Incorporated.
6. Sankoh, O., Sevalie, S., & Weston, M. (2018). Mental health in Africa. The Lancet Global Health, 6(9), e954-e955. doi:https://doi.org/10.1016/S2214-109X(18)30303-6