Screening for HIV: Recommendation Statement

Summary of Recommendations The U.S. Preventive Services Task Force (USPSTF) strongly recommends that clinicians screen for HIV all adolescents and adults at increased risk for HIV infection (see Clinical Considerations for discussion of risk factors). This is a grade A recommendation. (See Appendix Table 1 for a description of the USPSTF classification of recommendations.) Appendix Table 1. U.S. Preventive Services Task Force Recommendations and Ratings The USPSTF found good evidence that both standard and U.S. Food and Drug Administration (FDA)approved rapid screening tests accurately detect HIV infection. The USPSTF also found good evidence that appropriately timed interventions, particularly highly active antiretroviral therapy (HAART), lead to improved health outcomes for many of those screened, including reduced risk for clinical progression and reduced mortality. Since false-positive test results are rare, harms associated with HIV screening are minimal. Potential harms of true-positive test results include increased anxiety, labeling, and effects on close relationships. Most adverse events associated with HAART, including metabolic disturbances associated with an increased risk for cardiovascular events, may be ameliorated by changes in regimen or appropriate treatment. The USPSTF concluded that the benefits of screening individuals at increased risk substantially outweigh potential harms. (See Appendix Table 2 for a description of the USPSTF classification of levels of evidence.) Appendix Table 2. U.S. Preventive Services Task Force Grades for Strength of Overall Evidence The USPSTF makes no recommendation for or against routinely screening for HIV adolescents and adults who are not at increased risk for HIV infection (see Clinical Considerations for discussion of risk factors). This is a grade C recommendation. The USPSTF found fair evidence that screening adolescents and adults not known to be at increased risk for HIV can detect additional individuals with HIV, and good evidence that appropriately timed interventions, especially HAART, lead to improved health outcomes for some of these individuals. However, the yield of screening persons without risk factors would be low, and potential harms associated with screening have been noted (see earlier discussion). The USPSTF concluded that the benefit of screening adolescents and adults without risk factors for HIV is too small relative to potential harms to justify a general recommendation. The USPSTF recommends that clinicians screen all pregnant women for HIV. This is a grade A recommendation. The USPSTF found good evidence that both standard and FDA-approved rapid screening tests accurately detect HIV infection in pregnant women and fair evidence that introduction of universal prenatal counseling and voluntary testing increases the proportion of HIV-infected women who receive a diagnosis and are treated before delivery. There is good evidence that recommended regimens of HAART are acceptable to pregnant women and lead to significantly reduced rates of mother-to-child transmission. Early detection of maternal HIV infection also allows for discussion of elective cesarean section and avoidance of breastfeeding, both of which are associated with lower HIV transmission rates. There is no evidence of an increase in fetal anomalies or other fetal harm associated with currently recommended antiretroviral regimens (with the exception of efavirenz; see following discussion). Serious or fatal maternal events are rare using currently recommended combination therapies. The USPSTF concluded that the benefits of screening all pregnant women substantially outweigh potential harms. Background In 1996, the USPSTF recommended routine counseling and screening for all persons at increased risk for HIV infection (a grade A recommendation) and routine counseling and screening for high-risk pregnant women, as well as those residing in communities where the prevalence of seropositive newborns is increased (a grade A recommendation) (1). At that time, the USPSTF found insufficient evidence to recommend for or against routine HIV screening for persons without identified risk factors (a grade C recommendation) and insufficient evidence to recommend for or against universal prenatal screening in low-prevalence communities (a grade C recommendation). Testing infants born to high-risk mothers was recommended when the antibody status of the mother is unknown (a grade B recommendation). Since then, the USPSTF approach to making recommendations has changed (2) and significant new evidence on screening for and treating HIV infection has been published in the medical literature. Therefore, this recommendation statement has been updated and revised on the basis of a new review of the literature, using the current USPSTF methodology. Clinical Considerations A person is considered at increased risk for HIV infection (and thus should be offered HIV testing) if he or she reports 1 or more individual risk factors or receives health care in a high-prevalence or high-risk clinical setting. Individual risk for HIV infection is assessed through a careful patient history. Those at increased risk (as determined by prevalence rates) include men who have had sex with men after 1975; men and women having unprotected sex with multiple partners; past or present injection drug users; men and women who exchange sex for money or drugs or have sex partners who do; individuals whose past or present sex partners were HIV-infected, bisexual, or injection drug users; persons being treated for sexually transmitted diseases (STDs); and persons with a history of blood transfusion between 1978 and 1985. Persons who request an HIV test despite reporting no individual risk factors may also be considered at increased risk, since this group is likely to include individuals not willing to disclose high-risk behaviors. There is good evidence of increased yield from routine HIV screening of persons who report no individual risk factors but are seen in high-risk or high-prevalence clinical settings. High-risk settings include STD clinics, correctional facilities, homeless shelters, tuberculosis clinics, clinics serving men who have sex with men, and adolescent health clinics with a high prevalence of STDs. High-prevalence settings are defined by the Centers for Disease Control and Prevention (CDC) as those known to have a 1% or greater prevalence of infection among the patient population being served. Where possible, clinicians should consider the prevalence of HIV infection or the risk characteristics of the population they serve in determining an appropriate screening strategy. Data are currently lacking to guide clinical decisions about the optimal frequency of HIV screening. Current evidence supports the benefit of identifying and treating asymptomatic individuals in immunologically advanced stages of HIV disease (CD4 cell counts <200 cells/mm3 [< 0.200 109 cells/L]) with HAART. Appropriate prophylaxis and immunization against certain opportunistic infections have also been shown to be effective interventions for these individuals. Use of HAART can be considered for asymptomatic individuals who are in an earlier stage of disease but are at high risk for disease progression (CD4 cell count <350 cells/mm3 [< 0.350 109 cells/L] or viral load >100000 copies/mL), although definitive evidence of a significant benefit of starting HAART at these counts is currently lacking. The standard test for diagnosing HIV infection, the repeatedly reactive enzyme immunoassay followed by confirmatory Western blot or immunofluorescent assay, is highly accurate (sensitivity and specificity, 99%). Rapid HIV antibody testing is also highly accurate; can be performed in 10 to 30 minutes; and, when offered at the point of care, is useful for screening high-risk patients who do not receive regular medical care (for example, those seen in emergency departments), as well as women with unknown HIV status who present in active labor. Early identification of maternal HIV seropositivity allows early antiretroviral treatment to prevent mother-to-child transmission, allows providers to avoid obstetric practices that may increase the risk for transmission, and allows an opportunity to counsel the mother against breastfeeding (also known to increase the risk for transmission). There is evidence that the adoption of opt-out strategies to screen pregnant women (who are informed that an HIV test will be conducted as a standard part of prenatal care unless they decline it) has resulted in higher testing rates. However, ethical and legal concerns of not obtaining specific informed consent for an HIV test using the opt-out strategy have been raised. While dramatic reductions in HIV transmission to neonates have been noted as a result of early prenatal detection and treatment, the extent to which detection of HIV infection and intervention during pregnancy may improve long-term maternal outcomes is unclear. Discussion Of the estimated 850000 to 950000 persons in the United States infected with HIV-1, 25% are thought to be unaware of their status (3, 4). If untreated, almost all infected individuals will eventually develop AIDS, defined by opportunistic infection or severe immune dysfunction. Despite significant recent advances in treatment, AIDS is the seventh leading cause of death in persons age 15 to 24 years and the fifth leading cause of death in persons age 25 to 44 years in the United States (5). Incidence rates of HIV (an estimated 40000 new infections annually) have remained steady in the United States over the past decade (6). This figure includes infection through mother-to-child (vertical) transmission, with approximately 300 infants infected each year. Women are the fastest-growing group of persons with new HIV diagnoses, and an estimated 6000 to 7000 HIV-positive women give birth each year in the United States (7, 8). Effective interventions are av