I saw this article in the local newspaper. It appears to be an AP story (Daniel Q. Haney), and it mentions some interesting things:
The number of AIDS-related deaths has been dropping over the past five or so years, although the HIV infection rate has remained fairly stable.
What accounts for HIV+ people living longer all of a sudden?
“On January 31, 1999, researches reported that they had convincing proof that HIV has spread three separate times from chimps to people–one of the transmissions starting the worldwide epidemic.”
Now, just how convincing was this proof? I had not heard that. (I had heard speculation, but that’s a little short of “convincing proof.”)
I think the effectiveness of the “cocktail therapy” approach to treating AIDS probably accounts for the decrease in AIDS deaths, as people are able to live longer with the disease and knock their viral counts much lower.
Not sure about the evidence for different instances of transmission of the disease from chimpanzees to humans.
For one thing, better and earlier treatment. In the early '80s, if you contracted HIV, they generally wouldn’t know you had it until you had AIDS, and there wasn’t all that much they could do for you, anyway. There were no medications to slow the progression of the virus. Then, they discovered HIV, and how to test for it, which meant they could tell you soon after infection that you were infected, and then protease inhibitors, and other drugs that interfere with HIV’s ability to reproduce, and all of a sudden, the life span of somebody infected with the virus got longer.
AIDS is a syndrome, a group of symptoms, not a certain count of HIV in the blood. HIV, is, of course, the virus, not the symptoms. Even if you have a high viral count of HIV, if you don’t display any symptoms, you don’t have AIDS.
This site has some info. on the HIV species jump. The theory is that HIV I came from chimps and HIV II came from sooty mangabees. I don’t know about a third strain. There are more recent articles about this (the one above is from 1998), but I don’t see them online.
Anyone who tests antibody positive is considered to have HIV infection, but to have “AIDS,” a person with a confirmed positive HIV test must also have a CD4 lymphocyte count under 200 (or under 14% of total lymphocytes) or have acquired one of about 33 opportunistic diseases. It is basically advanced HIV disease. Before 1985, we didn’t have a test for HIV, so could only track AIDS cases as they occurred. Since 1996, with the introduction of protease inhibitors and other antiretroviral drugs, many people don’t progress from HIV to AIDS (for the foreseeable future), so it is valuable to track HIV cases as well. Here is a staff report I wrote about this: http://www.straightdope.com/mailbag/mnamed.html .
Still, many states only track AIDS, but not HIV, for a variety of emotional/political reasons I won’t go into.
In my state, most “new” AIDS cases that are reported to the epidemiology office are folks who delayed or avoided testing or accessing treatment for their infection and are coming in late, often being diagnosed with HIV for the first time as well as AIDS.
Absolutely right. Just wanted to add that the T-cell (a type of white blood cell) count in the patient’s blood is often used as an indicator of the onset/progression of AIDS.