HIV & Dried Blood?!

HIV & Dried Blood?

Hey guys, got a question. Can HIV survive in dried blood? How long can it live for? I was going to open a door and I noticed about a quarter size of dried blood by the handle. I'm not exactly sure if I touched it, but lets assume I did. When I got home, I didn't really have any soap to wash it off with, but I did have some Purel alcoholic stuff and hot water. I then took a shower with regular shampoo and hot water. My question is this: if the blood was HIV positive, how long would it have to be dried for the HIV to die and am I at any risk of getting it? Also, if the HIV was not dead, did I spread it by getting wet onto other surfaces, like my shower or floor when I was wet? Please help!
Thanks

Being stuck with a needle that has HIV infected blood, as has happened to thousands of health care workers, is a terrifying experience, but it very rarely results in HIV infection. Studies of such exposures find that only about 1 in 333 people who experience HIV-infected needle sticks seroconvert (Cardo 1997, Gerberding 1994, Henderson 1990), and that a total of only about 50 seroconversions from infected needles have been reported worldwide since HIV was targeted as the cause in 1984. This is an incredibly small number when compared to other blood borne diseases that are of similar prevalence.

This risk of seroconversion after a needle stick, 1 in 333, is less than the prevalence of HIV in the general population of the United States, which is about 1 in 250 people (Okie 1997). This raises the question whether these people really got HIV from the needle stick, since picking randomly from the population will result in more HIV positive people (1 in 240) than picking randomly from people who have been stuck by a needle (1 in 333). One could even argue, somewhat facetiously, that being stuck by a needle reduces your risk, just as using "dirty" needles for IV drug injections might reduce your risk. The 50 cases of seroconversion that are claimed to have occured in the world were reported in a multitude of small studies, with only one or two seroconversions per study. An in depth analysis of these studies would be quite revealing, but is unfortunately beyond the scope of this book. Instead, two of the largest and best controlled studies will be discussed, to serve as examples.

Gerberding (1994) found one case of seroconversion out of 327 cases of HIV-infected needle sticks. These all occurred over the space of 10 years in a clinic that specialized in HIV and AIDS. This single case of seroconversion was a woman who developed a flu-like illness about two weeks after the needle stick occurred, and then tested HIV positive two weeks after that. Another study by Henderson et al. (1990) reports a similar circumstance, where the HIV positive test occurred two weeks after a "severe mononucleosis-like illness, characterized by persistent fever, malaise, and weight loss". These types of anecdotal cases are what led to the conclusion that, at least in some cases, the initial stages of HIV seroconversion result in flu-like symptoms.

There is a completely different way to view this result, however.

Both the flu and mononucleosis have been found to cause false positives on HIV antibody tests (Cordes 1995, Challakeree 1993, MacKenzie 1992). False positives occur for all antibody tests, and are much more likely to occur after people have had an infectious illness, at which time there is a high quantity of many different types of antibodies present in a person's blood. No reports are made by Gerberding et al or Henderson et al of any repeat tests in the two health care workers who seroconverted to confirm the diagnosis, and thus it is not known whether these people may have converted back to HIV negative status after their levels of antibodies returned to normal, which can take a number of months. People who experience a needle stick from HIV infected blood experience several months of stress and social isolation, which people who are HIV positive experience on a permanent basis. This may have also weakened their immune system and made them more susceptible to the flu and other common infections, thus increasing their likelihood of a false positive result. False positives, and other problems with the antibody tests, will be covered in more detail in Problem#7: How Reliable Are HIV Antibody Tests?

A final aspect of Gerberding's findings presents another serious question about whether HIV can be transmitted via blood-contaminated needle sticks. They compared the extremely low rate of HIV antibody seroconversion to rates of hepatitis B seroconversion among the health care workers at their HIV-AIDS clinic. Hepatitis B is transmitted the same way that HIV is supposedly transmitted, via direct blood to blood contact or by intimate sexual contacts, and yet, in their own words, "the incidence of hepatitis B was 55 times greater than that of HIV, and 38 times greater than hepatitis C" (p. 1415). Since the setting of this study was a clinic specializing in HIV and AIDS, the prevalence of hepatitis B in the patients seen at the clinic was not expected to be much higher than the 25% to 40% prevalence of HIV positivity. Although not the subject of this paper, problems are also revealed with regards to Hepatitis C infectivity, and there are many other inconsistencies with this virus, as well (Duesberg 1996).