More commonly known as AIDS, acquired immunodeficiency syndrome is a lethal disease originating from the human immunodeficiency virus (HIV). If HIV is left untreated, the infected person’s immune system will become significantly weaker and this will lead to the progression of AIDS, which is classified as the most advanced stage of the HIV infection 5.
There are countless speculations surrounding the origin of the human immunodeficiency virus and many believe that the virus was contracted by humans who hunted meat from monkeys and became exposed to their contaminated blood 1, 3, 7. In 1999, researchers discovered a strain of the simian immunodeficiency virus (SIV) in a subspecies of chimpanzees which were native to equatorial West Africa. This virus attacks the immune system of the Cercopithecoidea family, much like HIV does to the human immune system. Today, there is authentic evidence that HIV and SIV are practically identical which proves that HIV virtually derived from SIV.
Genetic analysis carried out after 1960 derived that HIV may have originated as early as 1910. From his preserved blood samples, researchers identified the first trace of HIV from 1959 in a deceased man from the country now known as the Democratic Republic of the Congo 7. In the early 1970s, doctors caught sight of multiple patients having severe and rarer opportunistic infections but were unaware at the time that a virus was the root cause of the development of these sicknesses. In its early days this disease was named “the disease gay-related immune deficiency”, or GRID for short, as both physicians and scientists established a class of signs and symptoms which were predominantly found in men who had sex with other men 7. However, in 1982, doctors found that intravenous drug users were also experiencing the same symptoms and realised that these were a result of a damaged immune system. The disease was then renamed to “acquired immunodeficiency syndrome”, AIDS for short 7.
HIV damages the human immune system and over time leads to AIDS. AIDS is the final stage of the HIV infection and at this point, the immune system is critically damaged and too weak to fight off normal infections 4, 8. Normally, when pathogens invade the body they can cause infections. The body’s immune defence is triggered as a response to these events and specific white blood cells, involved in immune response, are activated. The specific type of white blood cells, helper T cells, boost the immune system’s response to pathogens in two different ways 8. The first way involves helper T cells releasing chemicals called cytokines which stimulate other white blood cells to move to the sight of the infection. These added white blood cells bombard the invading pathogen, as well as other infected cells. Secondly, helper T cells also release cytokines which instruct various white blood cells to multiply and these newly made cells create markers known as antibodies. Antibodies can pinpoint the identical non-self-intruders all around the body and attach to the invasive bacteria or virus, marking them as the aim of attack for the immune system to destroy 8.
When infected with HIV, the virus journeys through the blood and other body fluids to mar and kill CD4 cells (crucial helper T cells) 4, 8. The virus enters these primary targeted helper T cells and once inside exploits the T cells’ ability to produced copies and increases its number by repeatedly copying itself. As these virus particles are produced, they exit the crippled helper T cell to invade other cells, leaving it impaired and unable to protect the body from the ongoing infection and finally, the T cell will die. It is in this way that HIV spreads and wipes out more helper T cells, resulting in a weakened immune system 4, 8. Exhausted immune systems are more vulnerable to other infections which take advantage of the body’s inability to protect itself. These infections are called opportunistic infections which often cause discomfort and in more serious cases, death 8. An opportunistic infection can be described as an illness that may occur more regularly or fatally in an individual who has a damaged immune system 5, 8. Inflammation of tissues covering the brain and spinal cord, called meningitis and respiratory illnesses such as tuberculosis and pneumonia are just a few of the many AIDS-related opportunistic infections, which themselves have associated symptoms.
HIV is passed from an infected person to an uninfected person via infected blood and body fluids, such as vaginal fluid and semen 2, 4, 5, 8. Unprotected sex and sharing hypodermic needles when using drugs are the two main methods of HIV transmission, however it can also be acquired from contaminated blood during organ transplants or blood transfusions 5, 8. HIV may also be passed from mother to child when breastfeeding or during childbirth 5, 8. A few weeks post-infection by HIV, flu-like symptoms such as chills and joint pain may occur, however, as the immune system deteriorates, the disease is usually asymptomatic until it has advanced to AIDS 5, 6. This is the stage at which infected patients will experience symptoms such as rapid weight loss and profuse night sweats from the underlying sicknesses which take advance of the hindered immune system 5.
A simple at home HIV test measures the CD4 count in the body, a positive test will detect a low count which will indicate the robustness of the immune system 5. A more accurate clinic test could be done to diagnose HIV, however, results could take up to 12 weeks 9. Although there is no cure for HIV, there are a class of drugs called antiretroviral (ART) medications which prevent the production, assembly and spread of new viruses by disrupting them from attaching to cells, giving the immune system a chance to fight infections 5, 8. These medications reduce the viral load so low that often, a test cannot detect the virus and this is called an undetectable viral load. In recent years, many organizations have supported the undetectable=untransmittable initiative which means that a person with an undetectable viral load cannot transmit HIV 6, 7.
The main ways in which HIV transmission can be prevented is by avoiding unprotected sex and sharing unclean needles 8, 6. Taking daily recommended doses of ART drugs can help infected patients to live long and healthy lives 5, 8.
In conclusion, it is “estimated that 1.1 million people in the United States have HIV, but one is seven people do not know it” 5, 7. Regular testing and educating people on the severity and transmission of this life-threatening disease may be the only way to reduce these statistics.
References
- Gao, F. (1999), Origin of HIV-1 in the chimpanzee Pan troglodytes troglodytes, retrieved from, http://www.ncbi.nlm.nih.gov/pubmed/9989410
- Faria, N.R. (2014), The early spread and epidemic ignition of HIV-1 in human populations, retrieved from, http://www.sciencemag.org/content/346/6205/56.abstract
- Bailes, E. (2003), Hybrid Origin of SIV in Chimpanzees, retrieved from, http://www.ncbi.nlm.nih.gov/pubmed/12805540
- Center for Substance Abuse Treatment. Substance Abuse Treatment for Persons with HIV/AIDS. Rockville (MD): Substance Abuse and Mental Health Services Administration (US); 2000. (Treatment Improvement Protocol (TIP) Series, No. 37.) Chapter 1– Introduction to HIV/AIDS, retrieved from, https://www.ncbi.nlm.nih.gov/books/NBK64928/
- The official U.S. Government website managed by the U.S. Department of Health & Human Services and supported by the Minority HIV/AIDS Fund, What are HIV and AIDS? and Too many people living with HIV in the U.S. don’t know it, updated 17 June 2019, retrieved from, https://www.hiv.gov/hiv-basics/overview/about-hiv-and-aids/what-are-hiv-and-aids
- Felman. A. (2018), Explaining HIV and AIDS, medically reviewed by Daniel Murrell, MD, 29 November 2018, retrieved from, https://www.medicalnewstoday.com/articles/17131
- Nall, R. (2018), RN, MSN, CRNA, HIC and AIDS: A timeline and history, medically reviewed by Daniel Murrell, MD, 4 December 2018, retrieved from, https://www.medicalnewstoday.com/articles/323877
- Nucleus Medical Media, (2013); video on Medical Animation: HIV and AIDS, retrieved from, https://www.youtube.com/watch?v=ng22Ucr33aw&t=1s
- Mayo Clinic Radio Health Minute (2018), HIV Testing, retrieved from, https://www.mayoclinic.org/tests-procedures/hiv-testing/about/pac-20385018