“If someone gets HIV, and then I have sex with them, how soon could they infect me?” This is a question we’ve heard thousands of times over the 15 years that we’ve been running an AIDS hotline. The answer has always been the same: People become infectious very quickly after their own infection. The only quandary was the exact definition of “very quickly.”
Now researchers at the University of North Carolina-Chapel Hill suggest that a newly infected individual can transmit HIV to someone else in just five days. Their study examined five people newly infected through unprotected sexual intercourse, finding them to be fully infectious to others by five to 13 days after infection.
Indeed, previous studies had shown that this early period of infectiousness will be one of the most dangerous periods: the virus is multiplying unchecked in the new host’s body because his/her own body has not yet begun to make an antibody immune response to try to control it. With these extreme virus levels, the individual is exceptionally infectious; within a few weeks, after antibody response has kicked in, viral quantities — and infectiousness — will fall to more “normal” levels.
This underscores the need for people to know their HIV status, preferably as soon after infection as possible, so they can refrain from exposing others, as well as begin to care for themselves.
This article appears in 2001.