The potential for transmission of human immunodeficiency virus through human bites

We review the potential for human immunodeficiency virus (HIV) transmission by human bites. HIV may be present in saliva, although infrequently and at low levels. In prospective studies, 13 people bitten by HIV-infected individuals have remained HIV seronegative. Only two cases have been published in which HIV transmission through bites may have occurred. Both blood-contaminated and cell-free saliva may contain HIV. The presence of blood in the saliva may potentially heighten the theoretical risk of HIV transmission through human bites. We have estimated the risk of HIV transmission through human bites and have compared it with the known risks of HIV seroconversion by needle stick (0.3-0.5%). Needle sticks, on average, could transmit 20 times more HIV-infected cells than would a human bite. We conclude that the transmission of HIV through human bites is biologically possible but remains unlikely, epidemiologically insignificant, and, as yet, not well documented.