Search

Purpose: To determine the status of the HIV epidemic in the United States and Canada., Methods: We used data on AIDS and HIV diagnoses for 1996-2005 reported to the United States and Canadian national surveillance systems to determine trends in AIDS and HIV (33 US states only) diagnoses and to identify population groups most affected by HIV. HIV incidence for Canada was determined using back-calculation methods. We also determined the proportion of persons diagnosed late (HIV diagnosis within 12 months before AIDS diagnosis)., Results: AIDS diagnosis rates were higher in 2005 among blacks (54.1 per 100,000) and Hispanics (18.0) compared with whites (5.9) in the United States and among blacks (4.7) and aboriginal peoples (4.9) compared with whites (0.7) in Canada. Since 2001, HIV diagnoses increased among men who have sex with men in both countries and in Canada, increased among persons from HIV-endemic countries and where heterosexual contact was the only identified risk of transmission. Overall, HIV incidence remained relatively stable in Canada during that period. A large proportion of persons were diagnosed late in the disease process (United States, 54.3%; Canada, 64.2%)., Conclusions: Rates of HIV transmission remain a challenge in both the United States and Canada as overall diagnosis rates have not decreased in recent years. Renewed prevention efforts are needed to further reduce the high HIV diagnosis rates among racial/ethnic minorities and to decrease HIV transmission among men who have sex with men.

Context: Incidence of human immunodeficiency virus (HIV) in the United States has not been directly measured. New assays that differentiate recent vs long-standing HIV infections allow improved estimation of HIV incidence., Objective: To estimate HIV incidence in the United States., Design, Setting, and Patients: Remnant diagnostic serum specimens from patients 13 years or older and newly diagnosed with HIV during 2006 in 22 states were tested with the BED HIV-1 capture enzyme immunoassay to classify infections as recent or long-standing. Information on HIV cases was reported to the Centers for Disease Control and Prevention through June 2007. Incidence of HIV in the 22 states during 2006 was estimated using a statistical approach with adjustment for testing frequency and extrapolated to the United States. Results were corroborated with back-calculation of HIV incidence for 1977-2006 based on HIV diagnoses from 40 states and AIDS incidence from 50 states and the District of Columbia., Main Outcome Measure: Estimated HIV incidence., Results: An estimated 39,400 persons were diagnosed with HIV in 2006 in the 22 states. Of 6864 diagnostic specimens tested using the BED assay, 2133 (31%) were classified as recent infections. Based on extrapolations from these data, the estimated number of new infections for the United States in 2006 was 56,300 (95% confidence interval [CI], 48,200-64,500); the estimated incidence rate was 22.8 per 100,000 population (95% CI, 19.5-26.1). Forty-five percent of infections were among black individuals and 53% among men who have sex with men. The back-calculation (n = 1.230 million HIV/AIDS cases reported by the end of 2006) yielded an estimate of 55,400 (95% CI, 50,000-60,800) new infections per year for 2003-2006 and indicated that HIV incidence increased in the mid-1990s, then slightly declined after 1999 and has been stable thereafter., Conclusions: This study provides the first direct estimates of HIV incidence in the United States using laboratory technologies previously implemented only in clinic-based settings. New HIV infections in the United States remain concentrated among men who have sex with men and among black individuals.

The recommendations for human immunodeficiency virus (HIV) testing in the United States were recently revised. An important goal of these revisions is to reduce the proportion of individuals infected with HIV who are unaware of their infection. In the new guidelines, screening is recommended for all individuals aged 13-64 years in any health care setting, provided that they are notified that testing will be performed and do not decline testing. It was further recommended that individuals at high risk for HIV infection be screened annually. Through wider screening, the identification of persons with unrecognized HIV is expected to facilitate treatment and allow better targeting of HIV prevention strategies.

The need for a new surveillance approach to understand the clinical outcomes and behaviors of people in care for HIV evolved from the new challenges for monitoring clinical outcomes in the HAART era, the impact of the epidemic on an increasing number of areas in the US, and the need for representative data to describe the epidemic and related resource utilization and needs. The Institute of Medicine recommended that the Centers for Disease Control and Prevention and the Heath Resources and Services Administration coordinate efforts to survey a random sample of HIV-infected persons in care, in order to more accurately measure the need for prevention and care services. The Medical Monitoring Project (MMP) was created to meet these needs. This manuscript describes the evolution and design of MMP, a new nationally representative clinical outcomes and behavioral surveillance system, and describes how MMP data will be used locally and nationally to identify care and treatment utilization needs, and to plan for prevention interventions and services.

HIV testing is an important and effective strategy for preventing HIV infection. Infected individuals who know their HIV serostatus are less likely to engage in high-risk sexual behavior, and it is estimated that knowledge of HIV serostatus in unaware persons could reduce new infections by more than 30%. The availability of rapid testing for HIV expands testing opportunities. Expanded routine, voluntary, and opt-out screening in health care settings is needed to reduce the number of persons who are unaware of their HIV-infected status, get newly diagnosed patients into care, and reduce transmission of HIV infection. This article summarizes a presentation on revisions to Centers for Disease Control and Prevention HIV screening recommendations made by Robert S. Janssen, MD, at the 9th Annual Ryan White CARE Act Clinical Update in Washington, DC, in August 2006. The original presentation is available as a Webcast at www.iasusa.org.

These recommendations for human immunodeficiency virus (HIV) testing are intended for all health-care providers in the public and private sectors, including those working in hospital emergency departments, urgent care clinics, inpatient services, substance abuse treatment clinics, public health clinics, community clinics, correctional health-care facilities, and primary care settings. The recommendations address HIV testing in health-care settings only. They do not modify existing guidelines concerning HIV counseling, testing, and referral for persons at high risk for HIV who seek or receive HIV testing in nonclinical settings (e.g., community-based organizations, outreach settings, or mobile vans). The objectives of these recommendations are to increase HIV screening of patients, including pregnant women, in health-care settings; foster earlier detection of HIV infection; identify and counsel persons with unrecognized HIV infection and link them to clinical and prevention services; and further reduce perinatal transmission of HIV in the United States. These revised recommendations update previous recommendations for HIV testing in health-care settings and for screening of pregnant women (CDC. Recommendations for HIV testing services for inpatients and outpatients in acute-care hospital settings. MMWR 1993;42[No. RR-2]:1-10; CDC. Revised guidelines for HIV counseling, testing, and referral. MMWR 2001;50[No. RR-19]:1-62; and CDC. Revised recommendations for HIV screening of pregnant women. MMWR 2001;50[No. RR-19]:63-85). Major revisions from previously published guidelines are as follows: For patients in all health-care settings HIV screening is recommended for patients in all health-care settings after the patient is notified that testing will be performed unless the patient declines (opt-out screening). Persons at high risk for HIV infection should be screened for HIV at least annually. Separate written consent for HIV testing should not be required; general consent for medical care should be considered sufficient to encompass consent for HIV testing. Prevention counseling should not be required with HIV diagnostic testing or as part of HIV screening programs in health-care settings. For pregnant women HIV screening should be included in the routine panel of prenatal screening tests for all pregnant women. HIV screening is recommended after the patient is notified that testing will be performed unless the patient declines (opt-out screening). Separate written consent for HIV testing should not be required; general consent for medical care should be considered sufficient to encompass consent for HIV testing. Repeat screening in the third trimester is recommended in certain jurisdictions with elevated rates of HIV infection among pregnant women.

Background: New HIV infections stem from people who are aware they are HIV positive (approximately 75% of infected persons in the USA) and those who are unaware of their HIV-positive status (approximately 25%)., Objective: We estimated the relative contribution of these two groups in sexually transmitting new HIV infections to at-risk (HIV-negative or unknown serostatus) partners in the USA., Methods: The parameters in the estimation included: number of people aware and unaware they are infected with HIV; 33% of the aware group are at low risk of transmitting HIV because of low/undetectable viral load; 57% relative reduction in the prevalence of unprotected anal and vaginal intercourse (UAV) with at-risk partners in persons aware (compared to unaware) they have HIV; and assumed differences in the average number of at-risk UAV partners in each awareness group (ranging from equal to twice as many in the unaware group)., Results: The proportion of sexually transmitted HIV from the HIV-positive unaware group was estimated to range from 0.54 (assuming no difference in average number of at-risk UAV partners between groups) to 0.70 (assuming twice as many at-risk UAV partners in the unaware group). Using the lower bounds, the transmission rate from the unaware group was 3.5 times that of the aware group after adjusting for population size differences between groups., Conclusion: The results indicate that the HIV/AIDS epidemic can be lessened substantially by increasing the number of HIV-positive persons who are aware of their status.

Objectives: We evaluated the correlates and contexts of HIV testing within the past year, subsequent risk reduction, and HIV seroconversion among young men who have sex with men (MSM)., Methods: Young men aged 23 to 29 years were approached, interviewed, counseled, and tested for HIV at 181 randomly sampled MSM-identified venues in six U.S. cities from 1998 through 2000. Analyses were restricted to 2,797 MSM who reported never testing HIV-positive., Results: Of the 2,797 MSM, 1,281 (46%) either never previously tested or had not tested in the past year (never/remote testers); 1,516 (54%) had tested in the past year (recent testers); and 271 (10%) tested HIV-positive as part of the study. Of 1,885 recent sex partners reported by HIV-infected participants, 68% were partners of never/remote testers. Of recent testers, 50% tested anonymously, 51% tested because of specific risks, 59% were counseled, 47% reported reducing their risks after testing, and 8% tested HIV-positive (percent HIV-infected by race: blacks, 24%; Hispanics, 6%; whites, 4%; Asians, 1%)., Conclusion: Nearly half of young MSM participants had not tested in the past year and HIV-infected never/remote testers accounted for approximately two thirds of recent partners potentially exposed to HIV. Of those who had tested recently, many MSM, especially those who are black, had already acquired HIV. To reduce HIV transmission and facilitate early diagnosis and entry into care, increased HIV testing among young at-risk MSM in the United States, especially those who are black, is needed.

Objectives: To compare the prevalence of high-risk sexual behaviors in HIV persons aware of their serostatus with that in HIV persons unaware of their status in the United States and to discuss implications for HIV prevention programs., Methods: A meta-analysis was conducted on 11 independent findings. Six findings compared HIV(+) aware persons with independent groups of HIV(+) unaware persons (between-group comparisons), and 5 findings compared seroconverting individuals before and after being notified of their HIV status (within-subject comparisons). Outcomes were self-reported unprotected anal or vaginal intercourse (UAV) during specified recall periods., Results: The analysis integrating all 11 findings indicated that the prevalence of UAV with any partner was an average of 53% (95% confidence interval [CI]: 45%-60%) lower in HIV persons aware of their status relative to HIV(+) persons unaware of their status. There was a 68% reduction (95% CI: 59%-76%) after adjusting the data of the primary studies to focus on UAV with partners who were not already HIV(+). The reductions were larger in between-group comparisons than in within-subject comparisons. Findings for men and women were highly similar., Conclusions: The prevalence of high-risk sexual behavior is reduced substantially after people become aware they are HIV(+). Increased emphasis on HIV testing and counseling is needed to reduce exposure to HIV(+) from persons unaware they are infected. Ongoing prevention services are needed for persons who know they are HIV(+) and continue to engage in high-risk behavior.

This study evaluated the magnitude and distribution of unrecognized HIV infection among young men who have sex with men (MSM) and of those with unrecognized infection, the prevalence and correlates of unprotected anal intercourse (UAI), perceived low risk for infection, and delayed HIV testing. MSM aged 15-29 years were approached, interviewed, counseled, and tested for HIV at 263 randomly sampled venues in 6 US cities from 1994-2000. Of 5649 MSM participants, 573 (10%) tested positive for HIV. Of these, 91% of black, 69% of Hispanic, and 60% of white MSM (77% overall) were unaware of their infection. The 439 MSM with unrecognized infection reported a total of 2253 male sex partners in the previous 6 months; 51% had UAI; 59% perceived that they were at low risk for being infected; and 55% had not tested in the previous year. The HIV epidemic among MSM in the United States continues unabated, in part, because many young HIV-infected MSM are unaware of their infection and unknowingly expose their partners to HIV. To advance HIV prevention in the third decade of HIV/AIDS, prevention programs must reduce unrecognized infection among young MSM by increasing the demand for and availability of HIV testing services.

Reducing new HIV infections in the United States requires allocating public resources to interventions that will have the greatest impact on reducing the number of new infections. We report on the organizational experience of a federal agency's efforts to align its HIV prevention resources to reflect the specific priorities of a five-year strategic plan that has as its goal a fifty percent reduction in the number of annual HIV infections nationwide. Structural and other impediments encountered during the alignment process, and the steps taken to minimize their impact are described, adding to the empirical data base of strategic planning experiences in the public sector.

Risk behavior information is essential for allocating resources and developing effective HIV prevention strategies. Over time, transmission risk information on HIV/AIDS cases has been less likely to be reported to the national surveillance system. The Centers for Disease Control and Prevention (CDC) invited approximately 30 experts in HIV/AIDS and behavioral research from state and local health departments, academia, community-based organizations, and the CDC to participate in a consultation in December 2001 to generate ideas on how best to deal with the lack of risk data. The group was charged with providing recommendations on methods for classifying and reporting risk information and for identifying methods and sources for improving ascertainment of transmission risk behaviors for individuals infected with HIV. This report describes the recommendations and the effects of implementing such recommended procedures on the national HIV/AIDS surveillance database.

Less sensitive (LS) HIV-1 enzyme immunoassays (EIAs) have significantly improved the quantity and quality of HIV surveillance data. The first LS-HIV-1 EIA, the Abbott 3A11-LS, provided reliable incidence data, but the assay required specialized equipment, and the lack of available reagents made testing difficult. This study evaluated the use of an alternate assay, a modified version of the Vironostika HIV-1 EIA (Vironostika-LS), to be used for LS testing. The Vironostika-LS has similar performance characteristics to the Abbott 3A11-LS with additional advantages. This 96-well formatted assay is commonly found in public health laboratories for routine HIV-1 testing and can be used with both serum and dried blood spot specimens. The estimated mean time from seroconversion (defined using a standardized optical density cutoff of 1.0) with the Vironostika-LS was 170 days (95% CI, 145-200 days). When the Vironostika-LS was applied to a matched serum set previously tested with the Abbott 3A11-LS, the Vironostika-LS accurately identified 97% of specimens with recent or long-standing HIV infection. The paper also reports Vironostika-LS quality control guidelines and the results from 3 rounds of proficiency testing.

The sensitive/less-sensitive (S/LS) enzyme immunoassay (EIA) testing strategy for discriminating "early" from "longstanding" HIV infection has been widely applied for detecting recent seroconverters and estimating HIV incidence rates. The originally developed assay (3A11-LS EIA; Abbott Laboratories, Abbott Park, IL) involved performance of LS EIAs using a bead-based assay that required specialized equipment and reagents of limited availability. In contrast, 96-microwell-based EIAs are more universally applied for HIV serodiagnosis throughout the world. The authors report development and preliminary validation of an LS protocol using an EIA in a 96-well format: the Vironostika HIV-1 MicroElisa System (Vironostika-LS EIA; Bio Merieux, Raleigh, NC). The results with samples from recent HIV-1 seroconverters, persons with longstanding HIV-1 asymptomatic infection, patients on highly active antiretroviral therapy, and AIDS patients show a high degree of correlation between the Vironostika-LS EIA and 3A11-LS EIA. The authors also demonstrate that the Abbott 3A11-LS EIA and Vironostika-LS EIA performed comparably on HIV-1-positive samples from persons infected with non-B HIV-1 subtypes. These results support the potential use of the Vironostika-LS EIA for detection of recent HIV-1 infections for incidence projections and for other epidemiologic, clinical, and molecular surveillance applications.

Protease inhibitors for treatment of HIV-1 have been linked with increased risk of hyperlipidaemia and hyperglycaemia. In a cohort of 5672 outpatients with HIV-1 seen at nine US HIV clinics between January, 1993, and January, 2002, the frequency of myocardial infarctions increased after the introduction of protease inhibitors in 1996 (test for trend, p=0.0125). We noted that 19 of 3247 patients taking, but only two of 2425 who did not take, protease inhibitors had a myocardial infarction (odds ratio 7.1, 95% CI 1.6-44.3; Cox proportional hazards model-adjusted for smoking, sex, age, diabetes, hyperlipidaemia, and hypertension-hazard ratio 6.5, 0.9-47.8). Our findings suggest that, although infrequent, use of protease inhibitors is associated with increased risk of myocardial infarction in patients with HIV-1.

Although the numbers of newly reported diagnoses of AIDS decreased in the 1990s, it is not clear whether they reflect a decreasing number of new HIV infections. Direct measurement of HIV incidence through follow-up cohort studies is difficult and costly. We estimated HIV incidence and trends in incidence among men who have sex with men (MSM) and heterosexual men and women at clinics for sexually transmitted diseases (STDs) by using a recently developed serologic testing algorithm that requires only a single blood specimen. Cross-sectional anonymous serosurveys were conducted at 13 STD clinics in nine cities in the United States from 1991 through 1997. Before anonymous HIV testing, demographic and clinical information was abstracted. Of 129,774 specimens tested, 362 (0.28%) were from persons estimated to be recently infected. Incidence among MSM was 7.1% (95% confidence interval (CI): 4.8-10.3), 14 times higher than that among heterosexuals, which was 0.5% (CI: 0.4- 0.7). Incidence among MSM and heterosexuals remained unchanged during the time studied. Decreasing rates of new AIDS diagnoses in the 1990s do not reflect stable rates of new HIV infections among MSM and heterosexual patients attending these clinics.

Objectives: We compared recent risk behaviors and HIV seroconversion among young men who have sex with men (MSM) who were first-time, infrequent, and repeat HIV testers., Methods: Male adolescents and young men aged 15 to 22 years were randomly sampled, interviewed, counseled, and tested for HIV at 194 gay-identified venues in seven U.S. cities from 1994 through 1998. Analyses were restricted to MSM who reported having never tested or last tested HIV-negative., Results: Of 3430 participants, 36% tested for the first time, 39% had tested infrequently (one or two times), and 26% had tested repeatedly (> or = three times). Compared with first-time testers, repeat testers were more likely to report recent risk behaviors and to acquire HIV (7% versus 4%). Over 75% of repeat testers who seroconverted acquired HIV within 1 year of their last test. Compared with repeat testers, first-time testers reported similar use of health care but delayed testing for nearly 2 additional years after initiating risk., Conclusions: Many young MSM soon acquire HIV after repeated use of HIV counseling and testing services. Providers must strengthen practices to identify, counsel, and test young MSM and provide enhanced behavioral interventions for those with persistent risks.

In the United States, HIV prevention programs have historically tailored activities for specific groups primarily on the basis of behavioral risk factors and demographic characteristics. Through the Serostatus Approach to Fighting the Epidemic (SAFE), the Centers for Disease Control and Prevention is now expanding prevention programs, especially for individuals with HIV, to reduce the risk of transmission as a supplement to current programs that primarily focus on reducing the risk of acquisition of the virus. For individuals with HIV, SAFE comprises action steps that focus on diagnosing all HIV-infected persons, linking them to appropriate high-quality care and prevention services, helping them adhere to treatment regimens, and supporting them in adopting and sustaining HIV risk reduction behavior. SAFE couple a traditional infectious disease control focus on the infected person with behavioral interventions that have been standard for HIV prevention programs.

Few studies have examined gender-specific factors associated with the nonuse of condoms among homeless and runaway youths (HRYs)-a population at high risk for HIV infection. In this article, we evaluate these factors and explore gender differences in background experiences, psychosocial functioning, and risk behaviors among HRYs from four U.S. metropolitan areas. Of 879 sexually active HRYs sampled, approximately 70% reported unprotected sexual intercourse during a 6-month period, and nearly a quarter reported never using condoms in the same period. Among males and females, having only one sex partner in the previous 6 months had the strongest association with nonuse of condoms. Among males, nonuse was also associated with having ever caused pregnancy, frequent marijuana use, prior physical victimization, and low self-control and sociability. Among females, nonuse was associated with knowledge of HIV status, prior sexual victimization, low social support, and infrequent marijuana use. These findings highlight the ongoing need for HIV prevention services for HRYs. Implications for the scope and content of these services are discussed.

Context: Studies conducted in the late 1980s on human immunodeficiency virus (HIV) infection among older men who have sex with men (MSM) suggested the epidemic had peaked; however, more recent studies in younger MSM have suggested continued high HIV incidence., Objective: To investigate the current state of the HIV epidemic among adolescent and young adult MSM in the United States by assessing the prevalence of HIV infection and associated risks in this population in metropolitan areas., Design: The Young Men's Survey, a cross-sectional, multisite, venue-based survey conducted from 1994 through 1998., Setting: One hundred ninety-four public venues frequented by young MSM in Baltimore, Md; Dallas, Tex; Los Angeles, Calif; Miami, Fla; New York, NY; the San Francisco (Calif) Bay Area; and Seattle, Wash., Subjects: A total of 3492 15- to 22-year-old MSM who consented to an interview and HIV testing., Main Outcome Measures: Prevalence of HIV infection and associated characteristics and risk behaviors., Results: Prevalence of HIV infection was high (overall, 7.2%; range for the 7 areas, 2.2%-12. 1%) and increased with age, from 0% among 15-year-olds to 9.7% among 22-year-olds. Multivariate-adjusted HIV infection prevalence was higher among blacks (odds ratio [OR], 6.3; 95% confidence interval [CI], 4.1-9.8), young men of mixed or other race (OR, 4.8; 95% CI, 3. 0-7.6), and Hispanics (OR, 2.3; 95% CI, 1.5-3.4), compared with whites (referent) and Asian Americans and Pacific Islanders (OR, 1. 1; 95% CI, 0.5-2.8). Factors most strongly associated with HIV infection were being black, mixed, or other race; having ever had anal sex with a man (OR, 5.0; 95% CI, 1.8-13.8); or having had sex with 20 or more men (OR, 3.0; 95% CI, 2.0-4.7). Only 46 (18%) of the 249 HIV-positive men knew they were infected before this testing; 37 (15%) were receiving medical care for HIV, and 19 (8%) were receiving medical drug therapy for HIV. Prevalence of unprotected anal sex during the past 6 months was high (overall, 41%; range, 33%-49%)., Conclusions: Among these young MSM, HIV prevalence was high, underscoring the need to evaluate and intensify prevention efforts for young MSM, particularly blacks, men of mixed race or ethnicity, Hispanics, and adolescents. JAMA. 2000;284:198-204

The emergence of a new infectious disease, AIDS, in the early 1980s resulted in the development of a national AIDS surveillance system. AIDS surveillance data provided an understanding of transmission risks and characterized communities affected by the epidemic. Later, these data provided the basis for allocating resources for prevention and treatment programs. New treatments have dramatically improved survival. Resulting declines in AIDS incidence and deaths offer hope that HIV disease can be successfully managed. However, to prevent and control HIV/AIDS in the coming decades, the public health community must address new challenges. These include the defining of the role of treatment in reducing infectiousness; the potential for an epidemic of treatment-resistant HIV; side effects of treatment; complacency that leads to relapses to high-risk behaviors; and inadequate surveillance and research capacity at state and local levels to guide the development of health interventions. Meeting these challenges will require reinvesting in the public health capacity of state and local health departments, restructuring HIV/AIDS surveillance programs to collect the data needed to guide the response to the epidemic, and providing timely answers to emerging epidemiologic questions.

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.

To describe HIV infection prevalence and prevalence trends for disadvantaged out-of-school youth in the United States, we analyzed the HIV prevalence for and demographic characteristics of youth, aged 16 through 21 years, who entered the U.S. Job Corps from January 1990 through December 1996. Job Corps is a federally funded jobs training program for socially and economically disadvantaged out-of-school youth. All 357,443 entrants residing at Job Corps centers during their training were tested for HIV infection; 822 (2.3 per 1000) were HIV-positive. HIV prevalence was higher for women than for men (2.8 per 1000 versus 2.0 per 1000; relative risk [RR]=1.4; 95% confidence interval [CI]=1.2-1.6). Among racial/ethnic groups, prevalence was highest for African Americans (3.8 per 1000). Prevalence was higher for African American women (4.9 per 1000) than for any other gender and racial/ethnic group. From 1990 through 1996, standardized HIV prevalence-stratified by age, race/ethnicity, home region, population of home metropolitan statistical area, and year of entry--declined for women and for men: for women, from 4.1 per 1000 in 1990 to 2.1 per 1000 in 1996 (p=.001); and for men, from 2.8 per 1000 in 1990 to 1.4 per 1000 in 1996 (p=.001). These data suggest that HIV prevalence for disadvantaged out-of-school youth declined from 1990 through 1996. However, considering their youth, prevalence was still high, particularly for women and African Americans, most notably African American women. These data support the need for ongoing HIV prevention programs targeting such youth.

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.

We developed a scheme using routinely available data to estimate the risk of human immunodeficiency virus (HIV) dementia in HIV-infected persons over time. We performed a longitudinal review of medical records from more than 100 medical facilities in 11 U.S. cities. A total of 19,462 HIV-infected persons without history of dementia enrolled in a multi-institution survey. The main outcome measure was the development of HIV dementia (1987 case definition) during the median follow-up period of 17 months (range, 1 to 72 months). Of 19,462 HIV-infected persons, HIV dementia developed in 880 persons (4.5%; 2.6% per person-year). The strongest predictors of HIV dementia were CD4+ T-lymphocyte count, anemia, and AIDS-defining infections or cancer. The 2-year probability of HIV dementia was highest for persons who had a CD4+ T-lymphocyte count of fewer than 100 cells/microL and an AIDS-defining illness or anemia or both (18.6 to 24.9%). Intermediate risk was observed in persons with CD4+ T-lymphocyte count of 100 to 199 cells/microL and an AIDS-defining illness or anemia or both or in persons with a CD4+ T-lymphocyte count of fewer than 100 cells/microL but without another risk factor (2-year probability, 10.4 to 15.2%). The 2-year probability that HIV dementia would develop was lowest (1.0%) for persons with CD4+ T-lymphocyte count of more than 200 cells/microL and no other risk factors. Risk stratification using routine clinical information provides information that may prove useful in patient care decisions.

Objective: To determine the association between human immunodeficiency virus (HIV) infection and stroke among young persons., Design: Retrospective case-control study., Setting: Large, inner-city public hospital., Participants: All patients aged 19 to 44 years with a diagnosis of stroke, whose HIV status was determined, admitted from January 1990 through June 1994. Controls matched for age and sex were selected from patients who were admitted during the same period for status asthmaticus whose HIV status was known., Main Outcome Measure: The associations of HIV infection with all strokes and with cerebral infarction, after adjustment for other cerebrovascular risk factors, were evaluated by Mantel-Haenszel stratified analyses. The subtypes and causes of stroke in HIV-infected patients were compared with HIV-seronegative patients., Results: The HIV infection was associated with stroke (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.0-5.3) and cerebral infarction (OR, 3.4; 95% CI, 1.1-8.9), after adjustment for other cerebrovascular risk factors. Among patients with stroke, cerebral infarction was more frequent in HIV-infected patients than in HIV-seronegative patients (20 [80%] of 25 vs 48 [56%] of 88, P = .04). The frequency of cerebral infarctions associated with meningitis (P < .001) and protein S deficiency (P = .06) was higher in HIV-infected patients than in seronegative patients., Conclusions: Our study suggests that HIV infection is associated with an increased risk of stroke, particularly cerebral infarction in young patients. This risk is probably mediated by increased susceptibility of HIV-infected patients to meningitis and protein S deficiency.

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.

Background: In the United States, transmission of the human immunodeficiency virus (HIV) by blood transfusion occurs almost exclusively when a recently infected blood donor is infectious but before antibodies to HIV become detectable (during the "window period"). We estimated the risk of HIV transmission caused by transfusion on the basis of the window period associated with the use of current, sensitive enzyme immunosorbent assays and recent data on HIV incidence among blood donors., Methods: We analyzed demographic and laboratory data on more than 4.1 million blood donations obtained in 1992 and 1993 in 19 regions served by the American National Red Cross, as well as the results of HIV-antibody tests of 4.9 million donations obtained in an additional 23 regions., Results: We estimated that, in the 19 study regions, 1 donation in every 360,000 (95 percent confidence interval, 210,000 to 1,140,000) was made during the window period. In addition, it is estimated that 1 in 2,600,000 donations was HIV-seropositive but was not identified as such because of an error in the laboratory. We estimated that 15 to 42 percent of window-period donations were discarded because they were seropositive on laboratory tests other than the HIV-antibody test. When these results were extrapolated to include the additional 23 Red Cross service regions, there was a risk of one case of HIV transmission for every 450,000 to 660,000 donations of screened blood. If the Red Cross centers are assumed to be representative of all U.S. blood centers, among the 12 million donations collected nationally each year an estimated 18 to 27 infectious donations are available for transfusion., Conclusions: The estimated risk of transmitting HIV by the transfusion of screened blood is very small and nearly half that estimated previously, primarily because the sensitivity of enzyme immunosorbent assays has been improved.

Objective: To describe the seroprevalence of human immunodeficiency virus type 1 (HIV-1) and risk factors for HIV-1 infection among teenagers attending selected clinics., Design: Anonymous, cross-sectional serosurveys conducted in 130 clinics in 24 cities., Settings: Adolescent medicine clinics, sexually transmitted disease clinics, clinics in juvenile detention and correctional facilities, and homeless and runaway youth centers., Patients: Teenagers in whom serum samples were drawn as part of routine medical services., Main Outcome Measures: Prevalence of HIV-1 infection and reported HIV risk behaviors., Results: From January 1, 1990 through December 31, 1992, serum specimens were collected from 79,802 teenagers; 591 of these specimens were positive for HIV-1 antibody. Seropositive test results were found in all 24 cities surveyed, and in 95 (73%) of the 130 clinics surveyed. The median clinic-specific prevalence was 0.2% (range, 0% to 1.4%) in 22 adolescent medicine clinics, 0.3% (range, 0% to 6.8%) in 33 correctional facilities, 0.5% (range, 0% to 3.5%) in 70 sexually transmitted disease clinics, and 1.1% (range, 0% to 4.1%) in five homeless youth centers. Rates exceeded 1% in 37 sites (28%). Excluding sites with many men reporting sex with men, rates in women were similar or somewhat higher than rates in men. Rates were highest among young men reporting sex with men, with clinic rates ranging from 16% to 17% in two homeless youth sites and 13% to 17% in two sexually transmitted disease clinics. Most teenagers with risk information reported heterosexual activity as their only potential risk exposure to HIV-1., Conclusions: Seroprevalence of HIV was generally low but varied by type of clinic and geographic area. The highest rates were observed among young women and gay men in some settings, suggesting that targeted prevention messages are needed.

Background: Routine, voluntary testing of hospital patients for the human immunodeficiency virus (HIV) has been proposed in order to identify those with early HIV infection in a setting where there is ready access to counseling, appropriate clinical referral, evaluation, and therapy. We studied the pattern of HIV infection among patients in 20 U.S. hospitals, in order to evaluate possible national strategies for the routine, voluntary HIV counseling and testing of hospital patients., Methods: Blood specimens remaining after clinical use from a systematically selected sample of patients at 20 hospitals in 15 U.S. cities were tested anonymously for antibody to HIV type 1 (HIV-1). Multivariate regression was used to determine which variables best predicted HIV seroprevalence in individual hospitals. Using these data, we estimated the number of HIV-positive patients in all U.S. hospitals and considered the efficiency of routine counseling and testing in different subgroups of patients and hospitals., Results: From September 1989 through October 1991, 9286 of 195,829 specimens (4.7 percent) were positive for HIV-1 in the 20 hospitals. The seroprevalence of HIV at these institutions ranged from 0.2 percent to 14.2 percent. Among HIV-positive patients, 32 percent had symptomatic HIV infection or the acquired immunodeficiency syndrome (AIDS) at the time of admission or evaluation. In the 20 hospitals, HIV seroprevalence was 10.4 times (95 percent confidence interval, 8.8 to 12.0) the AIDS-diagnosis rate (the annual number of patients with new diagnoses of AIDS per 1000 discharges in 1990). In a multivariate model that included 13 hospital-specific variables, only the AIDS-diagnosis rate was associated with the hospital-specific HIV-seroprevalence rate (P less than 0.001). Using these data and the AIDS-diagnosis rates for all U.S. acute care hospitals, we estimated that 225,000 HIV-positive persons were hospitalized (95 percent confidence interval, 190,000 to 260,000) in all 5558 such hospitals in 1990, including 163,000 persons presenting with conditions other than HIV or AIDS (95 percent confidence interval, 130,000 to 196,000). In 1990, in 593 U.S. hospitals with AIDS-diagnosis rates of 1.0 or more per 1000 discharges, HIV testing of patients 15 to 54 years old (3 million patients, or 12.0 percent of all patients in U.S. acute care hospitals) would have identified an estimated 68 percent of all HIV-positive patients (110,000 patients) who were admitted with conditions other than symptomatic HIV infection or AIDS., Conclusions: We estimate that about 225,000 HIV-positive persons were hospitalized in 1990, of whom only one third were admitted for symptomatic HIV infection or AIDS. Routine, voluntary HIV testing of patients 15 to 54 years old in hospitals with 1 or more patients with newly diagnosed AIDS per 1000 discharges per year could potentially have identified as many as 110,000 patients with HIV infection that was previously unrecognized.