The risk of transmission of HIV-1 through non-percutaneous, non-sexual modes--a review.

To date, three well-documented modes of transmission of HIV-1 (sexual, percutaneous and perinatal) have been described. Although the theoretical possibility exists for HIV-1 transmission through other routes, including non-percutaneous, non-sexual modes often referred to as 'casual' contact (and several anecdotal reports suggest this possibility), there is no credible epidemiological evidence to support this. Fourteen combined surveys, with over 750 individuals with potential exposure through non-percutaneous, non-sexual modes of contact, have failed to find a single case of HIV-1 infection (upper bound of 95% confidence interval = 0.40%), indicating that the risk of transmission by non-percutaneous, non-sexual modes is remote. Given the emotionally charged concerns about transmission of an infection which may end fatally in a high proportion of affected individuals, critical review of the low probability of transmission through non-percutaneous, non-sexual modes is important so that preventive efforts can be focused appropriately.