l read your answer about the origins of AIDS and I have a few questions about it. Primarily, is SIV fatal in monkeys just like HIV is in humans and does it cause any symptoms at all? Secondly, you mentioned the drinking of an infected monkey's blood or eating it's raw meat as several ways that the virus could've made the jump to humans. But l have also heard that sexual contact with monkeys could also have been a means for the jump. Is that a myth or is it possible? Thank you for your time. Your help will be much appreciated
When we are talking about the origin of the AIDS Virus, your question regarding sexual contact between monkeys and humans is actually a very common one.
All evidence indicates that the monkey AIDS virus (also known as Simian Immunodeficiency Virus or SIV), and even the cat AIDS virus (also known as Feline Immunodeficiency Virus or FIV) have been in existence long before the HIV virus first infected humans. Both SIV and FIV cause diseases very similar to human AIDS, and can sometimes be fatal to monkeys and cats (but these viruses are harmless to humans). In addition, all of these viruses are transmitted in very similar ways (sexual contact, mother-to-baby, blood-to-blood contact, etc.). Evidence strongly indicates that HIV had originated from the SIV virus (based on genetic similarities between SIV and HIV). This most likely occurred by humans being directly exposed to monkey blood. There is no significant evidence that HIV was derived from the cat AIDS virus (FIV).
Realistically speaking, it would be highly unlikely that SIV could have made it's way from monkeys into people through sexual contact. The chances of a person being capable of having sex with a monkey (through intercourse, giving oral sex, etc.) is highly unlikely. If you see the size difference between humans and monkeys, and the behavior of monkeys (either in zoos or in nature), you would see quite well that the possibilities of sexual intercourse or oral sex with monkeys is realistically very unlikely. In addition, humans having sex with animals (also known as bestiality) is very uncommon.
In regard to HIV being derived from FIV, this would be quite unlikely based on all available evidence. I also find it realistically very unlikely for cats to be having sex with humans! The link between SIV and FIV is less clear, although I also find it very doubtful that cats would be having sex with monkeys! But somewhere in the evolutionary past, there had to be some sort of link between AIDS in monkeys and AIDS in cats; this could have occurred either by a direct blood-to-blood exposure (for example by fights between these animals or through predator-prey interaction), or a through a common viral "ancestor".
In summary, it is realistically extremely doubtful that HIV first entered humans through any form of sexual contact with monkeys, cats, or any other animal for that matter.
If you have any further questions, please feel free to call the Centers for Disease Control at 1.800.232.4636 (Nationwide).