Public Health Service Guidelines for the Management of Possible Sexual, Injecting-Drug-Use, or Other Nonoccupational Exposure to HIV, Including Considerations Related to Antiretroviral Therapy

Research Needs

Rigorously designed and executed studies are needed to evaluate the efficacy of antiretroviral agents in preventing HIV infection after nonoccupational exposures. Studies should include assessment of the rates of demand for antiretroviral therapy; the proportion of requests that stem from high-risk exposures; the rates of acceptance of therapy when offered; the patterns of drug prescriptions; the agents, doses, and duration of therapy associated with efficacy; the levels of patient adherence when therapy is prescribed; the rates of toxicity to drugs prescribed; and the costs of therapy. In addition, HIV isolated from patients infected despite therapy should be monitored to document the rates of acquisition of strains with genotypic or phenotypic antiretroviral resistance to medications taken. When possible, patient strains should be compared with HIV isolated from the reported source patients.

Studies also are needed to determine a) the distribution of knowledge about antiretroviral postexposure prophylaxis among those with nonoccupational HIV exposure, b) the effect of the availability of antiretroviral prophylaxis on HIV risk behaviors at the individual or community level, and c) the frequency of exposures for which therapy might be recommended.

Animal studies designed to mimic nonoccupational exposure to HIV, the timing of therapy initiation, and the antiretroviral drugs used for humans could provide additional information about the usefulness of drugs prescribed at specific intervals after exposure and for defined durations. Drugs or drug combinations that demonstrate promise for reducing retroviral transmission might be more easily documented in animal models.