undetectable plasma HIV levels, can still transmit HIV

the clinician should assume that all patients who are receiving therapy, even those with undetectable plasma HIV levels, can still transmit HIV. Patients who have treatment interruptions, whether scheduled or not, should be advised that this will likely lead to a rise in plasma viral load and increased risk for transmission. Another concern related to adherence to antiretroviral therapy is the development of drug-resistant mutations with subsequent transmission of drug-resistant viral strains. Several reports suggest that transmission of drug-resistant HIV occurs in the United States (138–141). Recent reports suggest that drug-resistant HIV strains might be less easily transmitted than wild-type virus (142), but these data are limited and their significance is unclear.
Effectiveness of Postexposure Prophylaxis for Non occupational Exposure to HIV. Although the U.S. Public Health Service recommends using antiretroviral drugs to reduce the likelihood of acquiring HIV infection from occupational exposure (e.g., accidental needle sticks received by health care workers) (143), limited data are available on efficacy of prophylaxis for nonoccupational exposure (97,143–147). Observational data suggesting effectiveness have been reported (148); however, postexposure prophylaxis might not protect against infection in all cases, and effectiveness of these regimens might be further hindered by lack of tolerability, potential toxicity, or viral resistance. Thus, avoiding exposure remains the best approach to preventing transmission, and the potential availability of postexposure prophylaxis should not be used as justification for engaging in risky behavior.
Tailored Interventions for Patients at High Risk for Transmitting HIV
Interventions tailored to the individual patient’s risks can be delivered to patients at highest risk for transmitting HIV infection and for acquiring new STDs. This includes patients whose risk screening indicates current sex or drug-injection practices that may lead to transmission, who have a current or recent STD, or who have mentioned items of concern in discussions with the clinician (149,150). Any positive results of screening for behavioral risks or STDs should be addressed in more detail with the patient so a more thorough risk assessment can be done and an appropriate risk-reduction plan can be discussed and agreed upon.
Although the efficacy of brief clinician-delivered interventions with HIV-infected patients has not been studied extensively, substantial evidence exists for the efficacy of provider-delivered, tailored messages for other health concerns (151–155). An attempt should be made to determine which of the patient’s risk behaviors and underlying concerns can be addressed during clinic visits and which might require referral (Box 3).
At a minimum, an appropriate referral should be made and the patient should be informed of the risks involved in continuing the behavior. HIV-infected persons who remain sexually active should be reminded that the only certain means for preventing transmission to noninfected persons is to restrict sex to partners known to be already infected with HIV and that they have a responsibility for disclosure of HIV serostatus to prospective sex partners. For mutually consensual sex with a person of unknown or discordant HIV serostatus, consistent and correct use of condoms made of latex, polyurethane, or other synthetic materials can substantially reduce the risk for HIV transmission. Also, some sex acts have relatively less risk for HIV transmission than others (Table 5). For HIV-infected patients who continue injection drug use, the provider should emphasize the risks associated with sharing needles and should provide information regarding substance abuse treatment and access to clean needles (Box 4) (156–158). Examples of targeted motivational messages on condom use and needle sharing are provided (Figures 1 and 2), and providers can individualize their own messages using these as a guide.