Until a safe and effective HIV vaccine is available, prevention of HIV infection will depend on HIV testing and counseling, including precautions regarding sexual practices and injection drug use, initiation of ART as a prevention tool for transmission to others, preexposure and postexposure use of antiretrovirals, 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 13% of people living with HIV in the United States do not know they have infection, the USPSTF recommends that clinicians screen for HIV infection in adolescents and adults ages 15 to 65 years at least once in a lifetime. Younger adolescents and older adults who are at increased risk should also be screened, with repeat screening as often as indicated for anyone at ongoing risk. Clinicians should review the risk factors for HIV infection with the patient and discuss HIV prevention strategies 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 medical care. Most public health guidelines and HIV specialists advocate for initiating care and treatment the same day that someone tests positive, including patients in safety-net settings (see C. Antiviral Treatment, below). Referrals for partner-notification services, social services, mental health services, and HIV prevention services should also be provided.
For patients whose test results are negative, clinicians should review HIV prevention strategies, needle use practices, or both. Pre-exposure prophylaxis and postexposure prophylaxis are highly effective HIV prevention strategies and are reviewed below. 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. Women as well as men having sex with men should understand how to use condoms to be sure that their partners are using them correctly. Several randomized trials in Africa demonstrated that male circumcision significantly reduced HIV incidence in men and, eventually, in female partners. This has ...