Until vaccination is a reality, prevention of HIV infection will depend on HIV testing and counseling, including precautions regarding sexual practices and injection drug use, initiation of antiretroviral treatment as a prevention tool for transmission to others, preexposure and postexposure use of antiretroviral treatment, perinatal management including antiretroviral treatment of the mother, screening of blood products, and infection control practices in the health care setting.
1. HIV testing and counseling
Primary care clinicians should routinely obtain a sexual history and provide risk factor assessment of their patients. Because approximately 15% of the HIV-infected persons in the United States do not know they are infected, the US Preventive Services Task Force recommends that clinicians screen for HIV infection in adolescents and adults ages 15 to 65 years. Younger adolescents and older adults who are at increased risk should also be screened. Clinicians should review the risk factors for HIV infection with the patient and discuss safer sex and safer needle use as well as the meaning of a positive test. Although the CDC recommends “opt-out” testing in medical settings, some states require specific written consent. For persons whose test results are positive, it is critically important that they be connected to ongoing medical care. Many public health systems advocate for initiating care and treatment the same day that someone tests positive if appropriate resources are available (see C. Antiviral Treatment, below). Referrals for partner-notification services, social services, mental health services, and HIV-prevention services should also be provided. Prevention interventions focused on the importance of HIV-infected persons not putting others at risk have been successful.
For patients whose test results are negative, clinicians should review safer sex and needle use practices, including counseling not to exchange bodily fluids unless they are in a long-term mutually monogamous relationship with someone who has tested HIV antibody-negative and has not engaged in unsafe sex, injection drug use, or other HIV risk behaviors for at least 6 months prior to or at any time since the negative test.
To prevent sexual transmission of HIV, only latex or polyurethane condoms should be used, along with a water-soluble lubricant. Although nonoxynol-9, a spermicide, kills HIV, it is contraindicated because in some patients it may cause genital ulcers that could facilitate HIV transmission. Patients should be counseled that condoms are not 100% effective. They should be made familiar with the use of condoms, including, specifically, the advice that condoms must be used every time, that space should be left at the tip of the condom as a receptacle for semen, that intercourse with a condom should not be attempted if the penis is only partially erect, that men should hold on to the base of the condom when withdrawing the penis to prevent slippage, and that condoms should not be reused. Although anal intercourse remains the sexual practice at highest risk for transmitting HIV, seroconversions have ...