What happened to home HIV test collection kits? Intent to use kits, actual use, and barriers to use among persons at risk for HIV infection.

Through sequential cross-sectional surveys, we examined intent to use home HIV test collection kits, actual use and barriers to use among persons at high risk for HIV infection. Interest in kits was assessed in the 1995-96 HIV Testing Survey (HITS, n=1683). Kit use, knowledge of kits and barriers to use were assessed in the 1998-99 HITS (n=1788), after kits had become widely available. When asked to choose among future testing options, 19% of 1995-96 participants intended to use kits. Untested participants were more likely than previously tested HIV-negative participants to choose kits for their next HIV test (p < 0.001). Among 1998-99 participants, only 24 (1%) had used kits; 46% had never heard of kits. Predictors of not knowing about kits included never having been HIV tested and black or Latino race. Common reasons for not using kits among participants aware of home test kits were concerns about accuracy, lack of in-person counselling and cost. Despite high rates of anticipated use, kits have had minimal impact on the testing behaviour of persons at high risk for HIV infection. Increasing awareness of kits, reducing price and addressing concerns about kit testing procedures may increase kit use, leading to more HIV testing by at-risk individuals.

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.

Trends in human immunodeficiency virus diagnoses among women in the United States, 1994-1998.

OBJECTIVE: Since the introduction of combination antiretroviral therapy in 1996, acquired immune deficiency syndrome (AIDS) data no longer provide information about trends in human immunodeficiency virus (HIV) incidence; therefore, we used HIV surveillance data to describe recent trends in HIV diagnoses among women. METHODS: Using HIV cases reported from 25 states with confidential HIV reporting, we examined new HIV diagnoses from 1994 to 1998 among women born between 1950 and 1979 by five-year birth cohorts. We adjusted for reporting delays and anticipated reclassification of cases reported without exposure risk. RESULTS: During the period, 24 171 cases of HIV infection were diagnosed among women. The annual number increased 4% from 1994 to 1995, then declined 12% from 1995 to 1998. The annual number of diagnoses attributed to heterosexual contact (HC) among women age 15 to 19 in 1994 (born 1975-1979) increased 117% from 1994 to 1998. Among older women, HC-related diagnoses remained stable or declined. The annual number of diagnoses attributed to injection drug use (IDU) among women age 15 to 19 in 1994 increased 90% from 1994 to 1998. The number of IDU-related diagnoses among older women declined between 31% and 59%. Diagnosis rates were higher among HC-related cases than among IDU cases. The rate for IDU-related diagnoses declined by nearly half over the period, but remained stable for HC-related diagnoses. CONCLUSIONS: HIV diagnoses among women decreased slightly between 1994 and 1998. As the youngest cohort of women reached the age where risk behaviors are initiated, however, the number of diagnoses attributed to IDU increased and the number of diagnoses attributed to HC more than doubled. It is in this youngest cohort, where risk behaviors have only recently been initiated, that HIV diagnoses most closely approximate trends in HIV incidence.

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.

Knowledge of partner risk and secondary transmission of HIV.

BACKGROUND: The number and proportion of people living longer with HIV and the proportion of people infected heterosexually have increased. We measured the frequency with which people with heterosexually acquired AIDS knew their partners' risk behaviors, the extent of secondary heterosexual transmission of HIV, and characterized people at risk for secondary heterosexual transmission. METHODS: For each of five sites (Alabama, California, Florida, New Jersey, and Texas) and for New York City, a sample of adults with AIDS was interviewed. Primary heterosexual transmission was contact with a partner who had a known risk factor for HIV infection. Secondary transmission was contact with an HIV-positive partner not known to have a risk for HIV. RESULTS: Among men, 35% knew that a sexual partner was HIV infected, 56% of women knew that a sexual partner was HIV infected. Among women, 12% knew that a partner was bisexual. Overall, 79% (460 of 581) reported a partner with a primary risk for HIV; among men, 236 of 293 (81%), and among women, 224 of 288 (78%) reported a partner with a primary risk. People categorized with secondary transmission were significantly more likely to be black and never married. People categorized with secondary transmission were more frequently women (53%), had less than a high school education (48%), and a history of drug use (52%). Men categorized with secondary transmission of HIV had a mean of 22 heterosexual partners; women had a mean of 16 partners. CONCLUSIONS: We found that many heterosexuals with AIDS did not know their sexual partners' risk for HIV, and that secondary heterosexual transmission probably results in a small proportion of all AIDS cases in the U.S.

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.

Successful implementation of perinatal HIV prevention guidelines. A multistate surveillance evaluation.

In 1994, zidovudine (ZDV) was demonstrated to substantially reduce perinatal transmission of the human immunodeficiency virus (HIV). Guidelines regarding the use of ZDV to reduce transmission and regarding counseling and voluntary testing of pregnant women were issued in 1994 and 1995, respectively. Surveillance methods were used to evaluate the implementation of these guidelines and to understand reasons for continued perinatal transmission of HIV. Population-based enhanced perinatal surveillance was used in seven states to collect information regarding mother-infant pairs in 1993, 1995, and 1996. Birth registries and HIV/Acquired immunodeficiency virus (AIDS) registries were matched to determine the number of HIV-infected women with diagnosis before delivery. Supplemental epidemiologic information was collected for 1,321 pairs. The estimated total number of HIV-infected women giving birth each year was derived from the Survey of Childbearing Women, an anonymous serologic survey of the prevalence of HIV infection among women giving birth. From 1993 through 1996, the proportion of HIV-infected women with diagnosis before delivery increased from 70% to 80%. The proportion of women with a diagnosis who received ZDV prenatally increased from 27% to 83% and intrapartum, 6% to 75%; for neonates, the increase was from 8% to 77%. Overall, 14% of women received no or only one prenatal care visit. A total of 36% of women who used illicit drugs during pregnancy had not had prenatal care. Of the children who received any ZDV, 8% were infected compared with 16% of those who received no ZDV. ZDV, used for treating pregnant HIV-infected women, has been rapidly adopted in clinical practice and has reduced the transmission of HIV. To achieve continued declines in perinatal transmission of HIV infection, continued progress is needed in the following areas: a) increases in the proportion of women who receive prenatal care and an HIV diagnosis; and b) implementation of rapid testing methods (when licensed rapid tests are available) or rapid turnaround of standard tests (expedited EIA tests).

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.

Duration of human immunodeficiency virus infection and likelihood of giving birth in a Medicaid population in Maryland.

The objective of this study was to examine the effect of duration of human immunodeficiency virus (HIV) infection on a woman's likelihood of giving birth. Using longitudinal data from the Maryland state Human Immunodeficiency Virus Information System and a retrospective cohort design, the authors compared 1,642 women with acquired immunodeficiency syndrome (AIDS) to 8,443 uninfected women enrolled in the Medicaid program between 1985 and 1995. The decade before AIDS diagnosis was divided into four 2.5-year periods. Proximity to AIDS diagnosis served as a proxy for duration of infection. An extension of the Cox model was used to estimate the relative risk for giving birth, with adjustment for covariates and repeated outcomes. The average number of births per 100 person-years was 6.0 for HIV-infected women and 11.1 for uninfected women (adjusted relative risk = 0.63; 95% confidence interval (CI): 0.57, 0.68). Accounting for duration of infection, the adjusted relative risks for birth among HIV-infected women, as compared with uninfected women, were 0.85 (95% CI: 0.71, 1.03), 0.74 (95% CI: 0.63, 0.86), 0.55 (95% CI: 0.47, 0.64), and 0.45 (95% CI: 0.38, 0.55) for successive 2.5-year periods before AIDS diagnosis. Demographic characteristics, contraception, abortion, fetal loss, or drug use could not fully explain the reductions. These results suggest that HIV-infected women experience a progressive reduction in births years before the onset of AIDS. This may compromise estimation of HIV prevalence and interpretation of time trends from serosurveillance of pregnant women.

AIDS among Asians and Pacific Islanders in the United States.

OBJECTIVE: To characterize Asians and Pacific Islanders in the United States with reported acquired immunodeficiency syndrome (AIDS). METHODS: AIDS surveillance data reported through June 1998 were analyzed. Characteristics of cumulative case patients, rates of AIDS incidence in 1996 through 1997, and trends from 1982 through 1996 were analyzed. RESULTS: Through December 1998, 4,928 Asian and Pacific Islander adults and 46 Asian and Pacific Islander children with AIDS were reported in the United States. Of the total cases, 89% were in men, and 79% of those were in men who have sex with men (MSM). Five states, which account for 63% of the Asian and Pacific Islander population in the United States, reported 78% of the cases: California (45%), Hawaii (12%), New York (15%), Texas (3%), and Washington (3%). Of the 92% of Asian and Pacific Islander patients with country of birth information, 59% were foreign-born, a percentage that corresponds to the distribution in the general population. The overall incidence rate per 100,000 for 1996 through 1997 was 12.8 (21.3 for men; 3.3 for women). The highest rate was in the Northeast (15.9), followed by the West (13.8), South (10.6), and Midwest (5.7). Tuberculosis, reported for 6% of Asians and Pacific Islanders, was higher among foreign-born than among U.S.-born Asians and Pacific Islanders (8% and 4%, respectively). Between 1982 and 1996, AIDS incidence among MSM increased and peaked in 1994. Among heterosexual contacts and injection drug users, incidence has increased but remained low. CONCLUSIONS: The AIDS epidemic among Asians and Pacific Islanders in the United States has primarily affected MSM and is concentrated in a few states where most Asians and Pacific Islanders reside. Prevention activities should include consideration of cultural diversity and an understanding of cultural norms regarding sexuality. Additional information on risk behaviors and seroprevalence among Asian and Pacific Islander MSM is needed to better guide prevention planning.

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.

Epidemiology of AIDS in incarcerated persons in the United States, 1994-1996.

OBJECTIVE: To compare demographic, behavioral, and geographic characteristics of incarcerated persons with AIDS and those of all persons with AIDS reported from January 1994 through December 1996. DESIGN: Population-based surveillance. SETTING: Medical records of persons for whom AIDS diagnosis was made in hospitals, clinics, and other settings (e.g., prisons) in the United States. PATIENTS: Adults (13 years or older) with AIDS reported from January 1994 through December 1996. RESULTS: Of the 220000 AIDS cases in adults, 4% were reported in incarcerated persons. Compared with all persons with AIDS, a higher proportion were male (89% versus 82%), black (58% versus 39%), younger at time of diagnosis (35 versus 37 years), had injected drugs (61% versus 27%), and were reported on the basis of the 1993 immunologic criteria (71% versus 50%). Fewer cases in incarcerated persons were diagnosed at death (3% versus 10%). The South (38%) and the Northeast (37%) United States accounted for the largest proportion of incarcerated persons. The 1996 AIDS rate for incarcerated persons (199 per 100000) was six times the national rate of 31 per 100000. Among persons incarcerated at time of diagnosis, rates for women were higher than for men (287 versus 185 per 100000) and higher for blacks and Hispanics than for whites (253, 313, and 100 per 100000, respectively). By state of report, Connecticut had the highest rate among incarcerated persons (1348 per 100000). CONCLUSION: These data illustrate differences in demographic, behavioral, and geographic characteristics of incarcerated persons compared with all persons with AIDS. However, they reflect only the minimum numbers of incarcerated persons with AIDS in the United States. Our results highlight the need for state health departments to work with correctional systems to ensure accurate and timely reporting of AIDS cases and to develop HIV prevention, education, and treatment both in prison and on release into the community.

Unreported AIDS-defining opportunistic illnesses in persons reported with HIV-related severe immunosuppression.

To better estimate the distribution of AIDS cases after the 1993 change in the case definition, we assessed the proportion of persons whose AIDS diagnosis was based on laboratory criteria for severe immunosuppression (CD4 count <200 cells/microl or <14%) and who also had an unreported opportunistic illness (OI) at the time of the CD4 report. Five U.S. reporting sites (Arizona; Los Angeles County, California; New Jersey; Oregon; and Washington State) reviewed AIDS cases reported between January 1 and June 30, 1993. From these sites, 3289 immunologic cases were reported; of these cases, 322 (9.8%; range, 1.6%-16.1%) were in persons who had an unreported OI. More of those who had an unreported OI were male, members of racial groups other than white, injection drug users, and had a CD4 count of <50 cells/microl at AIDS diagnosis. Because of recent advances in OI prophylaxis and treatment of HIV infection, studies monitoring HIV-related morbidity should assess the occurrence of OIs in a sample of persons reported with HIV and severe immunosuppression. Such assessment will ensure representative ascertainment of initial AIDS-defining OIs and thus improve the usefulness of the data for public health planning and the allocation of resources for patient care.

Trends in perinatal transmission of HIV/AIDS in the United States.

CONTEXT: Since 1994, the US Public Health Service (PHS) has recommended routine, voluntary prenatal human immunodeficiency virus (HIV) testing and zidovudine therapy to reduce perinatal HIV transmission. OBJECTIVE: To describe trends in incidence of perinatal AIDS and factors contributing to these trends, particularly the effect of PHS perinatal HIV recommendations. DESIGN, SETTING, AND PARTICIPANTS: Analysis of nationwide AIDS surveillance data and data from HIV-reporting states through June 1998. MAIN OUTCOME MEASURES: Trends in AIDS by year of diagnosis, incidence rates of AIDS and Pneumocystis carinii pneumonia (PCP) among infants younger than 1 year from US natality data for birth cohorts 1988 to 1996; expected number of infants with AIDS from national serosurvey data; and zidovudine use data from selected HIV-reporting states. RESULTS: Perinatal AIDS cases peaked in 1992 and then declined 67% from 1992 through 1997, including an 80% decline in infants and a 66% decline in children aged 1 to 5 years. Rates of AIDS among infants (per 100000 births) declined 69%, from 8.9 in 1992 to 2.8 in 1996 compared with a 17% decline in births to HIV-infected women from 1992 (n = 6990) to 1995 (n = 5797). Among infants, PCP rates per 100000 declined 67% (from 4.5 in 1992 to 1.5 in 1996), similar to the decline in other AIDS conditions. The percentage of perinatally exposed children born from 1993 through 1997 whose mothers were tested for HIV before giving birth increased from 70% to 94%; the percentage who received zidovudine increased from 7% to 91%. CONCLUSIONS: According to these data, substantial declines in AIDS incidence were temporally associated with an increase in zidovudine use to reduce perinatal HIV transmission, demonstrating substantial success in implementing PHS guidelines. Reductions in the numbers of births and effects of therapy in delaying AIDS do not explain the decline.

Trends in AIDS among Hispanics in the United States, 1991-1996.

OBJECTIVES: This article describes recent trends in AIDS among US Hispanics. METHODS: Incidence rates were calculated from AIDS surveillance data for persons diagnosed from 1991 through 1996. Increases in the number of cases among Hispanics were calculated by linear regression. RESULTS: Of the 415,864 persons diagnosed with AIDS from 1991 through 1996, 19% were Hispanic. Among Hispanics with AIDS, 67% were born in the United States or Puerto Rico. The relative risk (RR) of AIDS for Hispanics compared with Whites was highest for women (RR = 7.0), followed by children (RR = 6.2) and men (RR = 2.8). Increases in the number of cases were higher among foreign-born Hispanics. CONCLUSIONS: An understanding of which Hispanic subgroups are at greatest risk for HIV infection is important for prevention efforts.

Is there really a heterosexual AIDS epidemic in the United States? Findings from a multisite validation study, 1992-1995. Mode of Transmission Validation Study Group.

The objective of this study was to verify the mode of exposure to the human immunodeficiency virus (HIV) among cases who obtained acquired immunodeficiency syndrome (AIDS) through heterosexual contact and to determine the proportion of cases initially reported with no risk but whose exposure may have been heterosexual. Adults aged > or = 13 years with AIDS, diagnosed from 1992 through 1995 with heterosexual risk or no risk at six US study sites (Alabama, California, Florida, New Jersey, New York City, and Texas), were eligible. Heterosexual risk was validated in 82% (1,610/1,952) of the heterosexual cases. Men were more likely than women to have a risk other than heterosexual (24% vs. 13%, chi2 p < 0.01). An HIV risk was identified for 351 (55%) of those cases with no risk, and men were more likely than women to remain without risk (48% vs. 38%, chi2 P = 0.02). Of the 415 men with no risk, 215 (52%) were reclassified: 94 (44%) were men who had sex with men, 61 (28%) were injection drug users, 48 (22%) had a heterosexual risk, and 12 (6%) had other exposures. Of the 219 women with no risk, 136 (62%) were reclassified: 82 (60%) had a heterosexual risk, 47 (35%) were injection drug users, and 6 (4%) had infection associated with transfusion. In conclusion, most cases reported with heterosexually acquired AIDS had valid heterosexual risk exposures.

Surveillance for AIDS-defining opportunistic illnesses, 1992-1997.

PROBLEM/CONDITION: Acquired immunodeficiency syndrome (AIDS)-defining opportunistic illnesses (OIs) are the major cause of morbidity and mortality among persons infected with human immunodeficiency virus (HIV). As a result of new treatments that reduce mortality for persons with AIDS, the number of persons living with AIDS is increasing, and the incidence of AIDS is decreasing. In 1997, an estimated 271,245 persons were living with AIDS in the United States and thus were at high risk for OIs. In 1997, an estimated 21,909 HIV-infected persons died with AIDS, nearly all as a result of OIs. REPORTING PERIOD COVERED: Aggregate data and trends for 1992-1997 were examined to determine a) the frequencies at which OIs occurred first; b) the incidence of OIs; c) the percentage of persons among those who have died who had had a given OI during their course of AIDS, and d) the frequency of prescriptions for antiretroviral therapy and prophylaxis for Pneumocystis carinii pneumonia (PCP) and for Mycobacterium avium complex disease (MAC). DESCRIPTION OF SYSTEM: Data were analyzed from the Adult/Adolescent Spectrum of HIV Disease (ASD) sentinel surveillance project, a prospective medical record review of HIV-infected persons aged > or = 13 years conducted in 11 U.S. cities. ASD data were standardized to national AIDS surveillance data for 1992-1997 by age; race; sex; country of birth; year of AIDS diagnosis; HIV exposure mode; and for incidence calculations, by CD4+ T-lymphocyte distribution. RESULTS: The incidence declined significantly for each of 15 of the 26 specific AIDS-defining OIs (p<0.05). PCP was the most common AIDS-defining OI to occur first (PCP was the first OI to occur for 36% of HIV-infected persons), the most common incident AIDS-defining OI (274 cases per 1000 person-years), and the most common AIDS-defining OI to have occurred during the course of AIDS (53% of persons who died with AIDS had PCP diagnosed at some time during their course of AIDS). Of persons with CD4+ T-lymphocyte counts <500 cells/microL, the number with prescriptions for triple combination therapy increased from zero in 1992 to 40% in 1997, and 80% of persons had a prescription for any antiretroviral therapy in 1997. Of persons with CD4+ T-lymphocyte counts <200 cells/microL, the percentage with prescriptions for PCP prophylaxis remained stable from 1992 through 1997 (range: 75% to 80%). Of persons with CD4+ T-lymphocyte counts <50 cells/microL, the percentage with prescriptions for MAC prophylaxis increased from 9% in 1992 to 44% in 1997. INTERPRETATIONS: The incidences of many OIs are decreasing primarily because of advances in HIV-related therapy. However, OIs are still occurring, especially when patients access care late during the course of disease. Even after accessing care, persons may develop OIs because of lack of prescription for prophylaxis, antiretroviral drug resistance, or poor adherence to therapy. During 1992-1997, most patients in need of PCP prophylaxis received a prescription for it; however, even in 1997, most patients in need of MAC prophylaxis did not receive a prescription for it. ACTIONS TAKEN: These surveillance data are used by persons involved with developing guidelines for preventing OIs to determine the importance of and trends in OIs and preventive therapy. CDC is developing population-based approaches for surveillance of HIV disease progression, OIs, and therapies with the goal of making these data available in more geographic areas to help assess public health and health-care programs.