If you've come into contact with some blood or other body fluid that you think might contain HIV, it's understandable to have some concern about the possibility of HIV transmission. But you can rest assured that there haven't been any cases of HIV transmission through casual contact with blood or semen that has left behind on a surface. There haven't even been any cases after people have come across discarded syringes or needles.
This is partly because it's extremely unusual for this situation to involve any opportunity for an infected body fluid to enter the person's bloodstream -- it does not reach a mucous membrane (such as the vagina or rectum) or an open wound.
So in practical terms, there's little reason to worry about contact with body fluids that have already been outside a person's body for some minutes.
There isn't a simple, straightforward answer to the question of how long HIV survives outside the body. In certain, specific circumstances it may survive more than a few minutes. But it generally does not remain infectious and certainly does not pose a threat to people's health.
The conditions that a body fluid is exposed to greatly affect survival. Air dries out the fluid, which contains the virus, greatly reducing viral amounts. On the other hand, in the enclosed space inside a used syringe (with limited exposure to air) the virus can survive some time -- this explains why re-using needles and syringes is risky.
More on HIV Transmission Risks at TheBody.com
To find out more about how HIV is passed on, we recommend the following articles:
In addition, our Q&A experts sometimes address questions about transmission risks in our "Ask the Experts" forums. Here are some of those questions and our experts' responses:
- hiv survival outside of the body -- divergence of opinions
I've seen many people say that the virus dies very quickly when exposed to air but I've found information elsewhere saying HIV can survive for 5-6 days outside the body in room temperature and drying does not affect its infectivity.
- How long does HIV survive outside the body?
I recently touched a door handle that had urine on it. I got the fluid on my palms and I was wondering if you could catch HIV like that. I think the urine had been there for about six hours.