Definition of the Prevention Area
HIV testing services (HTS) help to prevent HIV transmission by identifying HIV positivity and informing individuals, partners and couples, and families of their HIV status and counseling them to develop appropriate measures to prevent or minimize HIV risks in sexual behavior, alcohol and drug use, and other behaviors. These measures differ according to the serostatus of the individual or 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).
HIV testing is also an essential step in access to other HIV services, including antiretroviral therapy (ART), prevention of mother-to-child transmission, and voluntary medical male circumcision. Successful HTS programs encompass effective linkages to clinical and community-based prevention, care and support, and treatment services.
Note that the term "HIV testing services," as currently used, encompasses the full range of accompanying services. However, studies on testing use various terms, including VCT (voluntary counseling and testing), HTC (HIV testing and counseling), and others. The summaries in this collection reflect this diversity.
Epidemiological Justification for the Prevention Area
The evidence on whether HTS directly affects HIV incidence is mixed. However, studies show that HTS 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. Also, some studies show a reduction in sexual risk behaviors for HIV-negative concordant partners who are tested together using couples HTS. Other studies suggest reductions in risk behaviors after HTS (e.g., reduction of unprotected sex or in number of sexual partners).
Studies on HTS 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 HTS may occur when HTS is available in the context of other harm reduction services. Serosorting, in which 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.
Core Programmatic Components
HTS is available through a wide variety of delivery models, and can be accessed through providers or initiated by clients. Provider-initiated HTS 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. In client-initiated HTS, an individual wants to get tested and searches for the best HTS center for him or her. This could include a stand-alone VCT site, a provider-initiated HTS site, or a community-based HTS site, such as a mobile or workplace HTS.
HTS should be specific to the type of epidemic, population, and level of risk. In concentrated epidemics, offering HTS at specific sites, such as outreach centers or mobile facilities, may be the most effective way to provide HTS to hard-to-reach populations. The World Health Organization (WHO) states that in settings with concentrated and low-level epidemics, provider-initiated HTS should be considered for sexually transmitted infection and tuberculosis (TB) clinics, services for key populations, and childbirth, antenatal care, and postpartum services. In generalized epidemics, WHO recommends offering provider-initiated HTS at all clinical settings, including services for sexually transmitted infections, TB, and antenatal care, as well as in- and outpatient services. In generalized epidemics, stand-alone, mobile, and home-based testing approaches have also demonstrated increased uptake of HTS among harder-to-reach populations, such as rural or higher-risk groups. For mixed epidemics, HTS programming can use a range of these options based on the epidemiological and social context of the country.
HTS, per WHO guidelines, includes the full range of services that should be provided in addition to HIV testing: counseling (pre-test information and post-test counseling); linkage to appropriate HIV prevention, treatment and care, and other clinical and support services; and coordination with laboratory services to ensure high-quality, accurate results. All forms of HIV testing should adhere to the WHO 5Cs: Consent, Confidentiality, Counseling, Correct test results, and Connection (linkage to prevention, treatment, and care services).
Current Status of Implementation Experience
The new global 90-90-90 targets call for 90 percent of all people with HIV to be diagnosed, 90 percent of people with HIV diagnosed to receive ART and 90 percent of those on ART to have a suppressed viral load by 2020. There have been significant increases in access to HTS; however, several challenges affect the diagnosis of HIV. HIV testing rates for men area generally lower than those for women in countries with high HIV prevalence where HTS is mainly offered in reproductive health services mostly antenatal care services. Provider-initiated HIV testing services need to be expanded to reach more pregnant women, children, TB patients, and adolescents. Access for key populations should be a priority because of marginalization and stigmatization. Generally, many people diagnosed with HIV are not linked to treatment and care because of barriers including transportation costs and distance to the facility, stigma, discrimination, fear of disclosure, staff shortages, and long waiting times, and because of policies that may prevent adolescents and key populations from accessing HTS.