Origin Of HIV/AIDS
The origin of HIV/AIDS is mystery for the scientists. The disease is a kind of puzzle. The first case of HIV/AIDS was discovered in USA in early 1980s. And since then, the most interesting questions about HIV/AIDS is that how did it came into existence?? It is believed that it originated in Africa. But how?
It is believed that HIV is a descendent of SIV (simian immunodeficiency virus) which is found in chimpanzees. However, the virus has some significant difference from the HIV.
Certain viruses can be transferred from one species to another. And this kind of viral transfer between animal and human is called zoonosis. It is strongly believed that by zoonosis HIV came into existence.
The next question is how did the SIV virus transferred to humans an how did SIV became HIV?? There are several theories related to its explanation. The most preferred one is “The Hunters Theory”.
The Hunter’s Theory
According to this, the SIV was transferred to humans by the consumption of undercooked monkey and ape meat- and their blood entering the wounds and cuts of the hunters. However, human body always fights against the antigens, so may be most of the SIV were eliminated from the body but the ones with some mutations survived.
When the viruses are subjected to change in the environmental conditions they undergo mutations. They get mutated according to the new environment. Mosquitoes get resistant to DDT after a long use of DDT. Now almost all the mosquitoes are resistant to DDT, even after the use of DDT is banned as the genes of resistance to DDT have been transferred. Just like that the viruses also undergo mutation. The stronger viruses produced new progeny with better adaptation.
It is reported that there were different strains of HIV each with some minor difference in the genetic constitution (the most common was the HIV-1 group M). This may be because of the reason that the viruses might have undergone mutation of different type. The changes in the genes may be different. And therefore they produced slightly different strains.
The transfer of retroviruses is still going on from primates to humans. Some of the diseases like the SFV (simian foamy virus) which was thought to be found in primates only were detected in humans. The main reason for such virus transfer is butchering and consumption of monkey and ape meat.
The Oral Polio Vaccine (OPV) Theory
In late 1950s, millions of people in Belgian Congo, Ruanda and Urundi were given the doses of oral polio vaccine called “Chat”. According to this theory, HIV transferred through this vaccine as this vaccine needs living tissue for its production/growth and it is believed that it was grown in the living tissues (kidney cells) of the chimpanzees. May be infected chimps were used for its production which resulted in the formation of the vaccine infected with SIV strains and when were given to the people, it caused the HIV. So this theory believes that HIV came into existence iatrogenically (via medical treatment).
But this theory was discarded. Oral polio doses are insufficient to cause this disease as the lining of mouth and stomach are good barriers to viruses. The virus needs to get into the blood stream to cause the disease. The vaccine was analyzed many times. Later on, it was declared that no traces of were present in the vaccine of HIV or SIV. Also it was later found that only the macaque monkey’s kidney cells were used which cannot be infected by SIV. Hence, the theory was discarded.
The Contaminated Needle Theory
This theory is just the extension of the hunter’s theory. The use of plastic syringes became very common as it was a cheap and sterile way to introduce the medicine in the body. But for the African healthcare professionals who were working in different medical programmes, the huge amount of needles would cost very high. So they would have used a single needle for injecting the medicine to many people without any sterilization in between. This resulted in the transfer of the virus from the infected one (the hunters) at a large amount.
The Colonialism Theory
This theory was given by Jim Moore in 2000. According to this, in late 19th and early 20th century, most of the Africa was under the colonial forces. Africans were forced to work as labourers in the labour camps. They were not provided with proper food and sanitation. This would have resulted in poor immune system. Also they might be given chimps as food as the source of energy. May be diseased chimp’s meat were served. So they got infected by the virus and weak immune system gave advantage to the virus to grow without any difficulty. Also, the camps employed prostitutes to keep the workers happy. This resulted in the further transmission of the virus. Moore supported this theory as these camps were set up during the period when the virus was transmitted to humans for the first time. It is also the extension of the hunter’s theory. It is also called the ‘heart of darkness’ theory.
The Conspiracy Theory:
According to this, it is believed that HIV is man-made. According to a survey, one in seven African Americans thinks that HIV was developed in the government laboratories to control the black population. One can understand by considering the history of the discrimination that African Americans faced. More than half of the new HIV cases are reported in the African Americans.
Some other points:
- HIV-1 is believed to be transferred from chimpanzees to humans and HIV-2 is believed to come from the Sooty Mangabeys. Transmission of the virus to humans may be in the similar way. HIV-2 is rarer, less infectious and causes AIDS in a longer period as compared to HIV-1.
- It is very strongly believed that Africa is continent where the first transfer of HIV took place from the chimps to humans, as the monkeys of South America and Asia have never been discovered to have the SIV strains that could cause HIV in humans.
We will never know who was the first person to be infected with the HIV virus but the scientists are still searching about the origin of HIV/AIDS and giving their theories. All the theories are given with supposition. So, god knows whether it came as discussed in hunter’s theory or were discovered in labs or by some other reasons. The only thing we can do is to prevent this disease as no cure is available.