HIV/AIDS. From a Medical Mystery to Future Research 🔍
Since its discovery in 1981, the pandemic of HIV/AIDS has become the greatest public health challenge in recent history. Currently, over 34 million persons worldwide are living with HIV. What is HIV, AIDS? How did it all begin? Let's take a dive into the history and current context of this condition📚.
What are HIV and AIDS?
Even though medicine has evolved in the last 40 years, HIV/AIDS is still an important public health concern. Over the years, 60 million people got infected with HIV and 25 million deaths occurred due to AIDS. Developing countries have the highest rate of mortality (especially sub-Saharan Africa).
HIV stands for Human Immunodeficiency Virus. There are two types of this virus: HIV-1 and HIV-2. HIV-1 is the principal cause of developing AIDS (acquired immune deficiency syndrome) and it has spread globally. HIV-2 is geographically restricted to West Africa and the transmission rate is lower. Most of the HIV-2 cases do not develop into AIDS. Therefore, AIDS is an infectious disease that develops after an infection with HIV.
HIV can be transmitted through numerous ways:
⦁ sexual: 80% of adults with HIV get infected after exposing mucosal surfaces (such as genital area), therefore AIDS is primarily classified as a sexually transmitted disease
⦁ percutaneous: through injuries that expose blood or shared use of needles
⦁ perinatal: from mother to infant, during pregnancy, birth and breastfeeding
⦁ blood transfusions
How does HIV cause AIDS?
Even though it has been researched for decades, the process in which HIV leads to AIDS is not elucidated but many hypotheses exist. Once inside the body, HIV-1 replicates and spreads very fast. The virus causes a loss of essential nutrients to the human body, such as selenium, cysteine, glutamine and tryptophan. As a consequence of these depletions, major symptoms of AIDS appear: immune system collapse, muscle wasting, higher susceptibility for cancer and heart conditions, premature aging, skin conditions, depression, diarrhea, psychosis and dementia. With a weak immune system, the body is susceptible to other infections as well. High transmissions of other STDs, such as gonorrhea and genital herpes are linked to HIV.
In many cases, symptoms of AIDS develop a long time after an individual got infected with HIV, due to the virus slowly creating serious deficiencies.
How did HIV suddenly appear?
Primates (chimpanzees, gorillas, mangabeys) are usually infected with many viruses, and some of them manage to be transmitted cross-species (from one species to another). One of those viruses is HIV. Interestingly enough, the HIV isn't deadly for the animal host. Originally from African primates, the HIV has undergone cross-species transmission and genetic modifications that resulted in humans contracting this virus and developing AIDS.
How the virus got transmitted from apes to humans, is still uncertain. Some say that it may have been through the exposure of wounds or mucous membranes to ape blood or body fluids. Such infections are presumed to have happened under the context of hunting.
The origin of AIDS pandemic
Studies show evidence that the HIV-1 spread started around 1910-1930 in colonial West Central Africa, when urban populations were expanding. All current documentation seems to suggest that the starting point of the AIDS pandemic was in Leopoldville/Kinshasa. The HIV-1 virus then spread for 50-70 years around the globe before it was identified. Countries from South Africa account for one-third of today’s global HIV infections.
Although the first identified cases were in MSM (men having sex with men) in the US and Western Europe, the greatest impact was in sub-Saharan Africa where the transmission happens amongst heterosexuals.
The history of discovering HIV
In June 1981, a report describing what is now known as AIDS, was published. The report described the case of five previous healthy homosexuals treated for pneumonia (lung infection). In the months to come, other cases of infections linked to low immunity appeared. Likewise, cases in heterosexuals were seen. Even though the infections were different amongst patients and the cause of the low immunity was unknown, researchers suggested that all of these conditions were linked to a sexually transmitted infection.
Over the years, cases of infections due to low immunity were identified in infants, suggesting a mother-to-infant transmission. Other affected groups emerged, such as injection drug users (IDUs), patients that received blood transfusions and healthcare workers with occupational exposure to blood, indicating a transmission through blood as well.
Only in 1983, the virus was identified and two years later, antibody testing was available. After this milestone, prevention methods started to be developed and implemented all over the globe:
⦁ prevention guidelines for MSM (men having sex with men): HIV testing, informing partners of previous/current infections and safe sex practices
⦁ promoting circumcision, as lack of circumcision was increasing the risk for males to acquire HIV and to transmit it.
⦁ Sub-Saharan Africa: in order to minimize the spread of HIV, the "ABC" strategy was implemented: "abstain, be faithful, and use condoms" and approachable phrases were used, such as "zero-grazing" and "condomize"
⦁ Thailand had a more specific approach. The "100% condom campaign" targeted female sex workers and their clients.
⦁ In Senegal, the culture of male circumcision, and the traditional and religious practices helped prevent the spread of HIV.
⦁ the option to avoid breastfeeding. When an HIV mother gives birth, there is a 21% risk of a mother-to-infant transmission. Prolonged breastfeeding (the norm in sub-Saharan Africa) adds a 14% chance of risk of infection. Until the invention of antiretrovirals, the decision to choose between stopping to breastfeed (with the risk of malnutrition, diarrhea and respiratory disease) and continuing to breastfeed (in total a 35% risk of HIV infections) had to be weighted by every mother.
⦁ US approach: near-universal testing of pregnant women, providing access to antiretroviral or prophylactic(preventive) treatment and avoidance of breastfeeding by HIV infected mothers have eliminated new pediatric HIV infections.
The HIV pandemic concerning IDUs (injection drug users) evolved differently. Most affected countries were in Southern Europe, South and South-East Asia and countries of the former Soviet Union. The measures taken for preventing the increase of cases included treatment of drug dependence and access to sterilized needles and syringes when treatment wasn't available.
The pandemic in developing countries regarding blood transfusion was a consequence of a lack of infrastructure regarding blood collection, storage, paid or family members as donors, increased need for blood transfusions for pregnant women and children suffering from malarial anemia. The WHO (world health organization) and local organizations managed to prevent the rise of HIV through blood transfusion by implementing HIV screening of donated blood.
Treatment and prevention
Nowadays, the most efficient treatment for AIDS is ART (antiretroviral treatment). It represents a combination of 3 drugs that suppress viral levels. Patients that undergo ART have lower viral levels, therefore reducing the chances of spreading the virus. It is not a cure, but a lifelong treatment, making it more difficult to comply with the treatment. As patients need to take the medicine daily, they may fail to follow the treatment schedule, leading to ineffective results and a growth in the viral levels. In the US, only 28% of HIV-positive people are undergoing treatment and have suppressed viral loads.
Antiretroviral drugs can be used as pre-exposure prophylaxis treatment as well for preventing sexual transmission of HIV.
Stigma of people with HIV
Worldwide, 3 million IDUs (injecting drug users) are estimated to be infected with HIV. Their access to treatment is limited because of stigma, discrimination and the view on drug dependence as a law enforcement and not a public health problem. Besides HIV, IDUs are usually infected with Hepatitis B and C, and tuberculosis.
The social stigma around HIV and AIDS has an impact on patients’ lifestyle and adherence to treatment. Studies show that because of this, the cohesion of ART treatment may be undermined and other factors are affected such as HIV status disclosure, social support and mental wellbeing.
As medicine develops constantly, the need to find a cure for HIV/AIDS is essential and promising. Scientists are working on several promising options:
⦁ Nanotechnology: is considered to improve the effects of delivering the medicine to patients.
⦁ Gene therapy: a gene is inserted into a cell in order to stop the spread of the virus
⦁ Immunotherapy: strategies to rebuild the immune system through substances that can change the immune response to the virus
⦁ Vaccine: over the last decades, the possibility of developing a vaccine has been deeply researched and it is ongoing; some studies show promising results with a possibility of reducing the chances of getting infected by 31%.
⦁ Vaginal and rectal microbicides: future treatment that would be applied inside the vagina/anus in order to prevent the transmission of HIV or other STDs
Stay tuned 🌺🐝!