The context of HIV/AIDS surveillance.

HIV surveillance and diagnostic testing for HIV infection share elements in common, yet differ notably in context. Clinical testing provides vital information for individual medical and behavioral decisions, whereas surveillance, which focuses on populations, provides information to develop policy, direct resources, and plan services. HIV/AIDS surveillance has evolved over the course of the epidemic, reflecting changes in scientific knowledge, populations affected, and information needs. Likewise, the benefits of early diagnosis of HIV have become increasingly apparent with advances in HIV treatment. This article examines the changing context of HIV/AIDS surveillance and discusses the potential impact of HIV surveillance practices and policies on HIV testing behaviors. Special emphasis is placed on the importance of protecting the confidentiality of HIV/AIDS surveillance data and on the role of health department in monitoring the impact of surveillance policies on test-seeking patterns and behaviors.

Detection of early HIV infection and estimation of incidence using a sensitive/less-sensitive enzyme immunoassay testing strategy at anonymous counseling and testing sites in San Francisco.

Timely estimates of HIV incidence are needed to monitor the epidemic and target primary prevention but have been difficult to obtain. We applied a sensitive/ less-sensitive (S/LS) enzyme immunoassay (EIA) testing strategy to stored HIV-positive sera (N = 452) to identify early infections, estimate incidence, and characterize correlates of recent seroconversion among persons seeking anonymous HIV testing in San Francisco from 1996 to 1998 (N = 21,292). Sera positive on a sensitive EIA but negative on a less-sensitive EIA were classified as early HIV infections; sera positive on both EIA were classified as long standing. Seventy-nine sera were from people with early HIV infection. Estimated HIV incidence was 1.1% per year (95% confidence interval [CI], 0.68%-1.6%) overall and 1.9% per year (95% CI, 1.2%-3.0%) among men who have sex with men (MSM). Early HIV infection among MSM was associated with injection drug use, unprotected receptive anal sex, and multiple sex partners in the previous year. No temporal trend in HIV incidence was noted over the study period. The S/LS strategy provides a practical public health tool to identify early HIV infection and estimate HIV incidence in a variety of study designs and settings.

New testing strategy to detect early HIV-1 infection for use in incidence estimates and for clinical and prevention purposes.

CONTEXT: Differentiating individuals with early human immunodeficiency virus 1 (HIV-1) infection from those infected for longer periods is difficult but important for estimating HIV incidence and for purposes of clinical care and prevention. OBJECTIVE: To develop and validate a serologic testing algorithm in which HIV-1-positive persons with reactive test results on a sensitive HIV-1 enzyme immunoassay (EIA) but nonreactive results on a less sensitive (LS) EIA are identified as having early infection. DESIGN: Diagnostic test and testing strategy development, validation, and application. Specimens were tested with both a sensitive HIV-1 EIA (3A11 assay) and a less sensitive modification of the same EIA (3A11-LS assay). SETTINGS AND PARTICIPANTS: For assay development: 104 persons seroconverting to HIV-1 comprising 38 plasma donors, 18 patients of a sexually transmitted disease clinic in Trinidad, and 48 participants in the San Francisco Men's Health Study (SFMHS); 268 men without the acquired immunodeficiency syndrome (AIDS) in the SFMHS who had been infected for at least 2.5 years; and 207 persons with clinical AIDS; for testing strategy validation: 488 men in the SFMHS from 1985 through 1990 and 1275449 repeat blood donors at 3 American Red Cross blood centers from 1993 through 1995; and for HIV-1 incidence estimates: 2717910 first-time blood donors. We retrospectively identified persons eligible for a study of early infection. MAIN OUTCOME MEASURE: Ability to identify early HIV infection. RESULTS: Estimated mean time from being 3A11 reactive/3A11-LS nonreactive to being 3A11 reactive/3A11-LS reactive was 129 days (95% confidence interval [CI], 109-149 days) [corrected]. Our testing strategy accurately diagnosed 95% of persons with early infection; however, 0.4% (1/268) of men with established infection and 2% (5/207) of persons with late-stage AIDS were misdiagnosed as having early HIV-1 infection. Average yearly incidence estimates in SFMHS subjects were 1.5% per year vs observed average incidence of 1.4 per 100 person-years. Incidence in repeat blood donors using the sensitive/less sensitive assay testing strategy was 2.95 per 100000 per year (95% CI, 1.14-6.53/100000) vs observed incidence of 2.60 per 100000 person-years (95% CI, 1.49-4.21/100000). Overall incidence in first-time blood donors was 7.18 per 100000 per year (95% CI, 4.51-11.20/100000) and did not change statistically significantly between 1993 and 1996. Use of the sensitive/less sensitive testing strategy alone would have identified all 17 persons with antibodies to HIV-1 eligible for a study of early HIV-1 infection and would have increased enrollment. CONCLUSIONS: The sensitive/less sensitive testing strategy provides accurate diagnosis of early HIV-1 infection, provides accurate estimates of HIV-1 incidence, can facilitate clinical studies of early HIV-1 infection, and provides information on HIV-1 infection duration for care planning.

Serologic test for syphilis as a surrogate marker for human immunodeficiency virus infection among United States blood donors.

BACKGROUND: This study evaluated the usefulness of the serologic test for syphilis (STS) in preventing the transmission of human immunodeficiency virus (HIV), hepatitis B and C viruses, and human T-lymphotropic virus via the transfusion of seronegative, infectious window-period blood. STUDY DESIGN AND METHODS: Demographic and laboratory information on blood donations made between January 1992 and June 1994 in 18 American Red Cross regions was analyzed. It was assumed that the same proportion of HIV-positive and HIV-infectious window-period donations reacted on STS and were negative on other screening tests (hepatitis B and C viruses and human T-lymphotropic virus). This proportion multiplied by the estimated number of HIV-infectious window-period donations is the number of post-screening HIV-infectious donations removed by STS. RESULTS: Of 4,468,570 donations, 12,145 (0.27%) were STS positive and 377 (0.008%) were HIV positive. Among donations that were negative on other screening tests, STS-reactive donations were 12 times more likely to be HIV positive (odds ratio = 11.9; 95% CI = 5,26). However, of an estimated 13 infectious window-period donations, 0.2 would have been removed because of a reactive STS, at a cost of over $16 million. CONCLUSION: STS is a poor marker and a costly strategy for preventing post-screening HIV infections and other blood-borne diseases.

Guidelines for designing rapid assessment surveys of HIV seroprevalence among hospitalized patients. Centers for Disease Control and Prevention.

The Centers for Disease Control and Prevention has developed guidelines for determining HIV seroprevalence among patients seeking medical care at acute-care hospitals. The guidelines enable hospital staff members to perform a simple, rapid, and inexpensive survey to determine seroprevalence among the patient population, protecting the anonymity of those who are tested. The guidelines are based on national experience with large-scale anonymous, unlinked HIV serosurveys. The data from a rapid assessment survey are particularly useful for evaluating the need to provide routine, voluntary HIV counseling and testing and treatment for HIV infection. Beyond that, such data can be used in targeting education efforts, in reinforcing the use of appropriate universal precautions, in resource allocation, and in determining the need for further studies of HIV infection among the population in the hospital catchment area.

HIV seroprevalence in hospital patients in rural Georgia.

To determine human immunodeficiency virus (HIV) seroprevalence among hospital patients in three rural community-based hospitals in southern Georgia, we anonymously tested patients 15 to 54 years old for antibodies to HIV-1 from residual blood specimens collected for routine diagnostic purposes. Data collected included age, sex, race, hospital service, presenting condition, physician's knowledge of HIV infection status, and discharge diagnosis. Of 1319 patients tested, seven (0.5%, 95% confidence interval = 0.2% to 1.1%) had antibodies to HIV-1. Of those seven, five had HIV infection unsuspected by their physicians, and four had an infectious disease. HIV seroprevalence was 0.5% for both men and women, 1.0% for blacks, and 0.3% for whites. HIV-positive patients were found on all hospital services. These results suggest that in rural southern Georgia hospitals, HIV should be routinely considered in the differential diagnosis of conditions that may be related to HIV. In addition, these data demonstrate a need for medical services or referral networks for HIV-related illnesses and a need for continuing HIV counseling and testing offered by local health departments in rural southern Georgia.