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HIV Prevention Knowledge Base

A Collection of Research and Tools to Help You Find What Works in Prevention

Biomedical Interventions: HIV Testing and Counseling as Prevention

I. Definition of the Prevention Area

As a stand-alone intervention, HIV testing and counseling (HTC) contributes to prevention of HIV transmission by identifying and informing individuals, partners and couples, and families of their HIV status and counseling them to develop appropriate sexual, injection, or other risk-reduction measures. These measures differ according to the serostatus of the individual or of couples, be they seroconcordant (both partners test either HIV-positive or HIV-negative) or serodiscordant (one partner tests HIV-positive and the other tests HIV-negative).

HTC is also a prerequisite to accessing such services as antiretroviral therapy, prevention of mother-to-child transmission, and voluntary medical male circumcision. Successful linkages to clinical and community-based prevention, care and support, and treatment services are important for any effective HTC program.

II. Epidemiological Justification for the Prevention Area

The evidence on whether HTC directly affects HIV incidence is mixed. However, studies show that HTC may have the greatest effect on sexual transmission of HIV for two population groups in particular: adult individuals who test HIV-positive and serodiscordant couples. In addition, some studies show a reduction in sexual risk behaviors for HIV-negative concordant partners who are tested together using couples HTC. Other studies suggest reductions in risk behaviors after HTC (e.g., reduction of unprotected sex or in number of sexual partners).

Studies on HTC among people who inject drugs are usually conducted in the context of other services—such as detoxification or drug treatment centers, and needle and syringe exchange—and reveal mixed results. Findings suggest that safer injection practices following HTC may occur when HTC is available in the context of other harm reduction services. Serosorting, when HIV-positive persons seek sexual partners who are HIV-positive, is another demonstrated behavior following HIV testing. The literature is strongest among men who have sex with men, but recent discussions suggest that individuals in generalized epidemics may also use this strategy.

III. Core Programmatic Components

HTC is available through a wide variety of delivery models. HTC can be accessed through providers or can be initiated by clients. Provider-initiated HTC uses “opt-out” testing, which is when all adults and adolescents (with or without symptoms) are tested for HIV as part of their overall health care unless the patient declines. Informed consent is stressed for this method. Client-initiated HTC is when an individual wants to get tested and searches for the best HTC center for him or her. This could include a stand-alone voluntary counseling and testing site, provider-initiated HTC site, or a community-based HTC site such as a mobile or workplace HTC.

HTC should be specific to the type of epidemic, population, and level of risk. In concentrated epidemics, offering HTC at specific sites, such as outreach centers or mobile facilities, may be the most effective way to reach hard-to-reach populations. The World Health Organization (WHO) states that provider-initiated HTC should be considered for sexually transmitted infection and tuberculosis clinics, for services for most-at-risk populations, and for childbirth, antenatal care, and postpartum services for concentrated and low-level epidemics. In generalized epidemics, WHO recommends providing provider-initiated HTC at all clinical settings, including services for sexually transmitted infections, tuberculosis, and antenatal care, as well as in- and outpatient services. Offering stand-alone, mobile, and home-based testing for harder-to-reach populations—such as rural or higher-risk groups—in generalized epidemics has also demonstrated increased uptake of HTC. For mixed epidemics, HTC programming can use a range of these options based on the epidemiological and social context of the country.

HTC minimum standards follow international guidance and include pre- and post-test counseling or information as well as referral and linkage to HIV prevention, care, support, and treatment services. The type of test (e.g., rapid testing with same-day results) also affects how successful HTC is in delivering high-quality test results and services. WHO guidelines recommend that post-test counseling be provided regardless of test result and should include an explanation of the test result, advice on risk reduction, and the provision of condoms and referrals. For those testing HIV-positive, counseling should also include emotional support, discussion of the patient’s safe disclosure to others of his or her HIV status, and referral of the patient’s partners and children for testing

IV. Current Status of Implementation Experience

To resolve questions about the impact of community- versus clinic-based HTC on the behavior of HIV-negative individuals, the U.S. National Institute of Mental Health sponsored Project Accept, the first randomized controlled study to determine whether behavioral changes encouraged by HTC reduce HIV incidence. The study was conducted in 14 communities in Thailand and 34 communities in sub-Saharan Africa. Each community was randomized to receive both community- and clinic-based HTC or clinic-based HTC alone. The study ended in 2011. Incidence data are not yet available, but interim results show that uptake of first-time testers is greater in the community- and clinic-based HTC sites compared to clinic-based HTC alone. WHO is also coordinating the MATCH Study, a multi-country, mixed-methods study of HTC models evaluating a range of variables, including service quality, uptake, health behavior, and equity. In 2011, data collection was ongoing in four countries: Burkina Faso, Kenya, Malawi, and Uganda.