The completeness, validity, and timeliness of AIDS surveillance data.

PURPOSE: To assess the completeness, validity, and timeliness of the AIDS surveillance system after the 1993 change in the surveillance case definition. METHODS: To assess completeness of AIDS case reporting, three study sites conducted a comparison of their AIDS surveillance registries with an independent source of information. To evaluate validity, the same sites conducted record reviews on a sample of reported AIDS cases, we then compared agreement between the original report and the record review for sex, race, and mode of transmission. To evaluate timeliness, we calculated the median delay from time of diagnosis to case report, before and after the change in case definition, in each of the three study sites. RESULTS: After expansion of the case definition, completeness of AIDS case reporting in hospitals (> or = 93%) and outpatient settings (> or = 90%) was high. Agreement between the information provided on the original case report and the medical record was > 98% for sex, > 83% for each race/ethnicity group; and > 67% for each risk group. The median reporting delay after the change was four months, but varied by site from three to six months. CONCLUSIONS: The completeness, validity, and timeliness of the AIDS surveillance system remains high after the 1993 change in the surveillance case definition. These findings might be useful for programs implementing integrated HIV and AIDS surveillance systems.

HIV in the United States at the turn of the century: an epidemic in transition.

OBJECTIVES: The current status of and changes in the HIV epidemic in the United States are described. METHODS: Surveillance data were used to evaluate time trends in AIDS diagnoses and deaths. Estimates of HIV incidence were derived from studies done during the 1990s; time trends in recent HIV incidence were inferred from HIV diagnoses and seroprevalence rates among young persons. RESULTS: Numbers of deaths and AIDS diagnoses decreased dramatically during 1996 and 1997 but stabilized or declined only slightly during 1998 and 1999. Proportional decreases were smallest among African American women, women in the South, and persons infected through heterosexual contact, HIV incidence has been roughly constant since 1992 in most populations with time trend data, remains highest among men who have sex with men and injection drug users, and typically is higher among African Americans than other racial/ethnic groups. CONCLUSIONS: The epidemic increasingly affects women minorities, persons infected through heterosexual contact, and the poor. Renewed interest and investment in HIV and AIDS surveillance and surveillance of behaviors associated with HIV transmission are essential to direct resources for prevention to populations with greatest need and to evaluate intervention programs.

Survival after AIDS diagnosis in adolescents and adults during the treatment era, United States, 1984-1997.

CONTEXT: Declines in the number of acquired immunodeficiency syndrome (AIDS) deaths were first observed in 1996, attributed to improvements in antiretroviral therapy and an increase in the proportion of persons receiving therapy. OBJECTIVE: To examine national trends in survival time among persons diagnosed as having AIDS in 1984-1997. DESIGN, SETTING, AND SUBJECTS: Retrospective cohort study using data from a population-based registry of AIDS cases and deaths reported in the United States. MAIN OUTCOME MEASURE: Months of survival after AIDS diagnosis through December 31, 1998, compared by year of diagnosis. RESULTS: Among 394 705 persons with an AIDS-defining opportunistic illness (OI) diagnosed in 1984-1997, median survival time improved from 11 months for 1984 diagnoses to 46 months for 1995 diagnoses. Among persons with an OI diagnosed in 1996 and 1997, 67% were alive at least 36 months after diagnosis and 77% were alive at least 24 months after diagnosis, respectively. Among 296 621 AIDS cases diagnosed during 1993-1997, 65% were based on immunologic criteria and 35% on OI criteria; 80% were among men; and 42% were among non-Hispanic blacks, 40% among non-Hispanic whites, 17% among Hispanics, 1% among Asians/Pacific islanders, and less than 1% among American Indians/Alaska natives. The probability of surviving at least 24 months increased from 67% for those with immunologic diagnoses in 1993 to 90% in 1997 and from 49% for those with OI diagnoses in 1993 to 80% in 1997. Survival time increased with each year of diagnosis from 1984 to 1997 for blacks, whites, and Hispanics. The greatest annual survival gains occurred among persons receiving an AIDS diagnosis in 1995 and 1996. CONCLUSIONS: Survival time after AIDS diagnosis improved from 1984 to 1997. While AIDS incidence is declining, improved survival times present a growing public health challenge as the number of persons living with chronic human immunodeficiency virus disease/AIDS increases.

A method for classification of HIV exposure category for women without HIV risk information.

An increasing number of cases of human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) among women is reported to state and territorial health departments without exposure risk information (i.e., no documented exposure to HIV through any of the recognized routes of HIV transmission). Because surveillance data are used to plan prevention and other services for HIV-infected persons, developing methods to accurately estimate exposure risk for HIV and AIDS cases initially reported without risk information and assisting states to analyze and interpret trends in the HIV epidemic by exposure risk category is important. In this report, a classification model using discriminant function analysis is described. The purpose of the classification model is to develop a proportionate distribution of exposure risk category for cases among women reported without risk information. The distribution was estimated based on behavioral and demographic data obtained from interviews with HIV-infected women; the interviews were conducted in 12 states during 1993-1996. Variables used in the analysis were alcohol abuse, noninjection-drug use, and crack use; year of HIV/AIDS diagnosis; age; employment; and region. As a result of the classification procedure, nearly all cases among women with no reported risk were classified into an exposure risk category: 81%, heterosexual contact; and 16%, injection-drug use. These proportions are higher than the current redistribution fractions (calculated from risk reclassification patterns and weighted by demographic characteristics) and reflect the increasing proportion of cases among women attributable to heterosexual contact with an infected partner. This report provides one method that could be applied to HIV surveillance data at the national level to estimate the proportion of cases in exposure risk categories. However, because the study in this report is limited in sample size and geographic representativeness, other models are also needed for adjusting risk exposure data at the national, state, and local levels.

Tracking the HIV epidemic: current issues, future challenges.

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.

HIV prevalence and associated risks in young men who have sex with men. Young Men's Survey Study Group.

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

Short-course oral zidovudine for prevention of mother-to-child transmission of HIV-1 in Abidjan, Côte d'Ivoire: a randomised trial.

BACKGROUND: In Africa, the risk of mother-to-child transmission of HIV-1 infection is high. Short-course perinatal oral zidovudine might decrease the rate of transmission. We assessed the safety and efficacy of such a regimen among HIV-1-seropositive breastfeeding women in Abidjan, Côte d'Ivoire. METHODS: From April, 1996, to February, 1998, all consenting, eligible HIV-1-seropositive pregnant women attending a public antenatal clinic in Abidjan were enrolled at 36 weeks' gestation and randomly assigned placebo or zidovudine (300 mg tablets), one tablet twice daily until the onset of labour, one tablet at onset of labour, and one tablet every 3 h until delivery. We used HIV-1-DNA PCR to test the infection status of babies at birth, 4 weeks, and 3 months. We stopped the study on Feb 18, 1998, when efficacy results were available from a study in Bangkok, Thailand, in which the same regimen was used in a non-breastfeeding population. FINDINGS: 280 women were enrolled (140 in each group). The median duration of the prenatal drug regimen was 27 days (range 1-80) and the median duration of labour was 7.5 h. Treatment was well tolerated with no withdrawals because of adverse events. All babies were breastfed. Among babies with known infection status at age 3 months, 30 (26.1%) of 115 babies in the placebo group and 19 (16.5%) of 115 in the zidovudine group were identified as HIV-1 infected. The estimated risk of HIV-1 transmission in the placebo and zidovudine groups were 21.7% and 12.2% (p=0.05) at 4 weeks, and 24.9% and 15.7% (p=0.07) at 3 months. Efficacy was 44% (95% CI -1 to 69) at age 4 weeks and 37% (-5 to 63) at 3 months. INTERPRETATION: Short-course oral zidovudine was safe, well tolerated, and decreased mother-to-child transmission of HIV-1 at age 3 months. Substantial efforts will be needed to ensure successful widespread implementation of such a regimen.

Efficacy of trimethoprim-sulphamethoxazole prophylaxis to decrease morbidity and mortality in HIV-1-infected patients with tuberculosis in Abidjan, Côte d'Ivoire: a randomised controlled trial.

BACKGROUND: There is a high incidence of opportunistic infection among HIV-1-infected patients with tuberculosis in Africa and, consequently, high mortality. We assessed the safety and efficacy of trimethoprim-sulphamethoxazole 800 mg/160 mg (co-trimoxazole) prophylaxis in prevention of such infections and in decrease of morbidity and mortality. METHODS: Between October, 1995, and April, 1998, we enrolled 771 HIV-1 seropositive and HIV-1 and HIV-2 dually seroreactive patients who had sputum-smear-positive pulmonary tuberculosis (median age 32 years [range 18-64], median CD4-cell count 317 cells/microL) attending Abidjan's four largest outpatient tuberculosis treatment centres. Patients were randomly assigned one daily tablet of co-trimoxazole (n=386) or placebo (n=385) 1 month after the start of a standard 6-month tuberculosis regimen. We assessed adherence to study drug and tolerance monthly for 5 months and every 3 months thereafter, as well as rates of admission to hospital. FINDINGS: Rates of laboratory and clinical adverse events were similar in the two groups. 51 patients in the co-trimoxazole group (13.8/100 person-years) and 86 in the placebo group (25.4/100 person-years) died (decrease In risk 46% [95% CI 23-62], p<0.001). 29 patients on co-trimoxazole (8.2/100 person-years) and 47 on placebo (15.0/100 person-years) were admitted to hospital at least once after randomisation (decrease 43% [10-64]), p=0.02). There were significantly fewer admissions for septicaemia and enteritis in the co-trimoxazole group than in the placebo group. INTERPRETATION: In HIV-1-infected patients with tuberculosis, daily co-trimoxazole prophylaxis was well tolerated and significantly decreased mortality and hospital admission rates. Our findings may have important implications for improvement of clinical care for such patients in Africa.

Trends in HIV prevalence among childbearing women in the United States, 1989-1994.

We used data from a national serosurvey to describe national and regional trends in the prevalence of HIV among women giving birth in the United States from 1989 through 1994, and to estimate the number of women between 15 and 44 years old with HIV infection who had not yet developed opportunistic infections defining AIDS. We compared these estimates with AIDS prevalence and mortality estimates from the national AIDS case surveillance system. HIV seroprevalence among childbearing women remained stable nationwide from 1989 through 1994, ranging from 1.5 to 1.7/1000 women. In the Northeast, seroprevalence declined significantly after 1989. Seroprevalence increased significantly in the South through 1991 and then stabilized, although seroprevalence among black women continued to increase through 1994 in some southern states. Although AIDS prevalence and mortality increased nationwide each year from 1989 through 1994, the number of women infected with HIV who had not yet developed AIDS changed little and was approximately 86,000 in 1994. Our data suggest that new HIV infections among women of reproductive age are occurring at a rate that offsets losses from this population due to aging, disease progression, and death.

HIV infection in disadvantaged out-of-school youth: prevalence for U.S. Job Corps entrants, 1990 through 1996.

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.

The current status of methods for estimating the prevalence of human immunodeficiency virus in the United States of America.

The prevalence of human immunodeficiency virus (HIV) infection can be estimated by two distinct methods. One method, back-calculation, is a complex statistical procedure that estimates the HIV epidemic curve. The second method is based on data from population-based surveys, which provide estimates of the proportion of persons infected with HIV within subgroups, and on the known or estimated population totals for these subgroups. Estimates from these methods are subject to substantial uncertainty and bias, both of which are difficult to quantify. We review recent use of these procedures to estimate HIV prevalence in the United States of America. We also summarize new data on the uncertainty and the bias in these estimates. Reliable estimates of HIV prevalence can be made only by synthesizing estimates from several procedures and by a comprehensive evaluation of relevant data. Future estimates of HIV prevalence will require modifications of these methods or the development of new methods.

Estimating the number of AIDS-defining opportunistic illness diagnoses from data collected under the 1993 AIDS surveillance definition.

Expansion of the surveillance definition for AIDS in the United States in 1993 caused a substantial distortion in the trend in AIDS incidence, mainly because CD4-positive (CD4+) T-lymphocyte criteria were added to the definition. To evaluate trends in the rate at which HIV-infected persons develop the opportunistic illnesses listed in the AIDS surveillance definition (AIDS-OIs), we developed a procedure for estimating the incidence of these diseases. This estimate is based primarily on the probability distributions of the time from a CD4+ count in given ranges to the diagnosis of the first AIDS-OI. Our estimates of AIDS-OI incidence change by <4% during most calendar quarters during 1991 through 1995 if we also include the estimated effects of unreported AIDS-OIs among persons with AIDS reported based on the CD4+ criteria. Our procedure eliminates the transient effect of adding the CD4+ criteria to the AIDS surveillance definition and permits us to evaluate trends in the incidence of AIDS-OIs.

Human immunodeficiency virus infection and stroke in young patients.

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.

Effect of the human immunodeficiency virus epidemic on mortality from opportunistic infections in the United States in 1993.

To measure the effect of the human immunodeficiency virus (HIV) epidemic on mortality from opportunistic infections (OIs) in 1993, national multiple-cause death certificate data were examined using two approaches. First, for each OI, the percentage of deaths with HIV infection reported as the underlying cause was calculated. Second, the age-adjusted rate of death per million population was compared with the rate predicted from a model of rates in 1970-1980 or 1979-1981, as available. The percentage of deaths with HIV as the underlying cause and the ratio of observed to predicted death rates were as follows: toxoplasmosis, 91% and 86 (5.24/0.06); cryptosporidiosis/isosporiasis, 90% and infinite (1.61/0.00); progressive multifocal leukoencephalopathy, 87% and 19 (2.58/0.13); pneumocystosis, 82% and 18 (15.44/0.87); cytomegalovirus disease, 82% and 17 (12.60/0.74); nontuberculous mycobacteriosis, 79% and 18 (15.51/0.84); cryptococcosis, 76% and 4 (5.80/1.35); and histoplasmosis, 68% and 6 (1.36/0.23). Thus, the HIV epidemic has greatly increased mortality from several OIs.

Late postnatal mother-to-child transmission of HIV-1 in Abidjan, Côte d'Ivoire.

BACKGROUND: HIV-1 can be transmitted from an infected mother to her infant through breastfeeding, although the precise risk of transmission by this route is unknown. A long-term follow-up of children born to HIV-infected women in Abidjan, Côte d'Ivoire, has enabled us to estimate this risk. METHODS: Children born to 138 HIV-1-seropositive women, 132 HIV-2-seropositive women, 69 women seroreactive to both HIV-1 and HIV-2, and 274 HIV-seronegative women were enrolled at birth and followed up for as long as 48 months. All children were breastfed (median duration 20 months). Blood samples for either or both HIV PCR and HIV serology were obtained at 1, 2, and 3 months of age, and every 3 months thereafter. Early HIV infection was defined as a positive HIV-1 PCR result obtained in the first 6 months of life. Late postnatal transmission was diagnosed when a child had a negative PCR at 3 or 6 months of age, followed by either or both a positive HIV-1 PCR at 9 months or older, or persistently positive HIV-1 serology at 15 months or older. FINDINGS: 82 children born to HIV-1-seropositive mothers and 57 children born to mothers seropositive for both HIV-1 and HIV-2 had PCR results for samples taken within the first 6 months. By 6 months of age, 23 (28%; 95% CI 19-39) of the 82 children born to HIV-1-seropositive mothers and ten (18%; 95% CI 9-30) of the 57 children born to dually seropositive mothers were HIV-1 infected. Among children whose PCR results were negative at or before age 6 months, and who were followed up beyond 6 months, an additional four (9%) of the 45 children born to HIV-1-seropositive mothers and two (5%) of the 39 children born to dually seropositive mothers became HIV infected. The estimated rates of late postnatal transmission, with account taken of loss to follow-up and the observed pattern of weaning, were 12% (95% CI 3-23) and 6% (0-14), respectively. One of the five children whose mothers seroconverted from HIV-negative to HIV-1, and one of seven children whose mothers seroconverted from HIV-2 to dual reactivity, became HIV-1 positive. No case of late postnatal transmission occurred in children born to HIV-2-positive or persistently HIV-negative mothers. INTERPRETATION: Breastfed children born to mothers seropositive for HIV-1 alone or seropositive for HIV-1 and HIV-2 in Abidjan are at substantial risk of late postnatal transmission. Early cessation of breastfeeding at 6 months of age should be assessed as a possible intervention to reduce postnatal transmission of HIV.

Update on the seroepidemiology of human immunodeficiency virus in the United States household population: NHANES III, 1988-1994.

To update the estimate of seroprevalence of HIV from the third National Health and Nutrition Examination Survey (NHANES III), data from the second phase of the survey were combined with previously published data to produce a more precise estimate. The testing was performed anonymously on 11,203 individuals 18-59 years of age examined from 1988 to 1994. Fifty-nine individuals were HIV positive, for an overall prevalence of 0.32%. The number of individuals living in households with HIV infection based on this estimate was 461,000, with a 95% confidence interval of 290,000-733,000. Analysis of nonresponse demonstrated that white and black men 40-59 years of age were least likely to participate in the survey. A sensitivity analysis demonstrated that this nonresponse may have biased the NHANES III estimate downward by 190,000 persons. Data from the second phase of the survey were used to analyze the association between drug use and HIV infection. Black women who used cocaine were 12 times more likely to be HIV positive compared with all tested black women (6.5% vs. 0.55%). This survey provides an estimate of HIV prevalence for individuals who reside in households but excludes some persons who are at higher risk for HIV infection, including prisoners and the homeless not residing in shelters.

Prevalence of HIV infection in the United States, 1984 to 1992.

OBJECTIVE: To estimate the number of persons infected with the human immunodeficiency virus (HIV) living in the United States and the change in HIV infection prevalence since 1984. DESIGN: We estimated HIV prevalence from 3 data sources. We estimated past HIV infection rates from a statistical procedure based on national acquired immunodeficiency syndrome (AIDS) case surveillance data and estimates of the time from HIV infection to AIDS diagnosis. We also analyzed HIV prevalence data from 2 national surveys, a survey of childbearing woman and a household survey of current health status. We used other data sources to adjust these survey estimates to include groups not covered in the surveys. RESULTS: Approximately 0.3% of US residents (650,000-900,000 persons) were infected with HIV in 1992. Approximately 0.6% of men (including adolescent boys > or = 13 years of age) were infected, including approximately 2% of non-Hispanic black men and 1% of Hispanic men. Approximately 0.1% of women (including adolescent girls > or = 13 years of age) were infected, including approximately 0.6% of non-Hispanic black women. Approximately half of all infected persons were men who had sex with men, and one fourth were injecting drug users. The prevalence of HIV infection increased from 1984 to 1992, with a greater relative increase among women than men. CONCLUSIONS: The 3 different data sources and methods are consistent in estimating that 650,000 to 900,000 persons were infected with HIV in the United States in 1992. Among adolescents and adults of both sexes, the proportion infected was substantially higher among non-Hispanic blacks and Hispanics than among non-Hispanic whites. HIV-related illness will be a major clinical and public health problem in the United States for years to come.

Prevalence and incidence of vertically acquired HIV infection in the United States.

OBJECTIVE: To estimate human immunodeficiency virus (HIV) type I prevalence among childbearing women, HIV incidence in infants, and the number of children living with HIV infection and acquired immunodeficiency syndrome as a result of transmission from mother to infant (vertical transmission). DESIGN: The national HIV serosurvey of childbearing women was used to estimate the incidence of vertically acquired HIV infection in children born between 1988 and 1993. Data from the national acquired immunodeficiency syndrome case surveillance system and a multicenter pediatric HIV surveillance project were modeled to estimate incidence in children born between 1978 and 1987. SETTING: Surveillance conducted by the Centers for Disease Control and Prevention, Atlanta, Ga, in collaboration with state and local health departments. RESULTS: Approximately 14,920 HIV-infected infants were born in the United States between 1978 and 1993. Of these, an estimated 12,240 children were living at the beginning of 1994; 26% were younger than 2 years, 35% were aged 2 to 4 years, and 39% were aged 5 years or older. Approximately 6530 HIV-infected women gave birth in the United States in 1993, and, based on a 25% vertical transmission rate, an estimated 1630 of their infants were HIV infected. CONCLUSIONS: These results provide a basis for estimating medical and other resource needs for HIV-infected women and their children and for measuring the impact of interventions to reduce vertical transmission of HIV.

The seroepidemiology of human immunodeficiency virus in the United States household population: NHANES III, 1988-1991.

To provide an estimate of the seroprevalence of human immunodeficiency virus (HIV) in a representative sample of the U.S. household population, serum samples from participants in the third National Health and Nutrition Examination Survey (NHANES III) were tested for HIV antibody. The testing was performed anonymously on 5,430 individuals 18-59 years old from phase 1 of NHANES III conducted from 1988 to 1991. Twenty-nine individuals were HIV positive. The total weighted prevalence was 0.39%. The population estimate of infected individuals was 547,000, with a 95% confidence interval of 299,000-1,020,000 infected persons. Black participants were four times more likely to be HIV positive than white/other individuals and three times more likely than Mexican Americans. Men were three times more likely to be infected than women. Higher nonresponse to the survey and to phlebotomy was observed in young white men; therefore these data provide a conservative estimate of HIV infection in the general household population. This estimate does not include individuals who do not live in households and who may be at higher risk of infection, such as persons in penal institutions, the homeless, or certain hospitalized patients.