|MadSci Network: Immunology|
Is it likely that hiv can enter the bloodsteam from a 6 day old finger cut? It is very unlikely that HIV could enter the bloodstream through a 6 day old finger cut, especially if the cut has healed over with unbroken skin. The risk is essentially zero. Being a scientist, it is very difficult to say exactly zero, but for all practical purposes it's zero. It's like the Powerball Lottery. You could play it all day, and the odds of winning are practically zero. Continuing with your question, if the fluid was dry, the odds are even closer to zero. In the lab, dried samples are treated as potentially infective, and that's good lab technique. But it is very hard to find active HIV in a dried sample. (Viable HIV have been found from high concentration dried samples kept in a constant humid environment, but this is a very artificial situation.) After 5 or 6 days, the newly healed skin will look pink since it is thinner and has not toughened (remodeled). But once the wound has healed over it is covered with skin cells. These cells lack the major receptor (CD4) for HIV and are generally not infected by HIV. (In the test tube, high concentration HIV can be forced into these cells using alternate receptors, but again, these are very artificial conditions.) In any case, the ideas involved with "safer sex" should be followed to reduce any chance of infection. This means avoiding exchange of fluids: http://www.advocatesforyouth.org/youth/health/safersex/index.htm http://www.adolescentaids.org/youth/hiv_u.html To alleviate any worries, an HIV test can be done. About a month after exposure, the test becomes useful. You also can talk to someone at one of these numbers: http://www.adolescentaids.org/youth/resource_nationwide.html I hope this answers your questions. Mike Conrad.
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