HIV/AIDS Surveillance Report: U.S. HIV and AIDS cases reported through December 1997

Details

• Alternative Title:
  HIV/AIDS Surveillance Report; Year-end Edition, Vol. 9, No. 2: U.S. HIV and AIDS cases reported through December 1997
• Corporate Authors:
  Centers for Disease Control and Prevention (CDC) (U.S.) ; National Center for HIV, STD, and TB Prevention. Division of HIV/AIDS Prevention — Surveillance and Epidemiology ; Division of HIV/AIDS Prevention. Surveillance Branch. Reporting and Analysis Section ; Division of HIV/AIDS Prevention. Statistics and Data Management Branch
• Description:
  Commentary: Through December 1997, 641,086 persons with AIDS have been reported to CDC (table 1). From 1995 to 1996, for the first time in the epidemic, the occurrence of AIDS-defining opportunistic illnesses (AIDS-OIs) among infected persons (tables 18-20) and deaths among persons reported with AIDS (tables 21-23) decreased 7 percent and 25 percent, respectively. These declines were largely due to the increasing use of combination antiretroviral therapy including protease inhibitors. Perinatally-acquired AIDS incidence continued a pattern of marked decline (table 20), principally reflecting successful strategies to promote voluntary prenatal HIV testing and reduce transmission rates through the administration of zidovudine perinatally. These treatment advances have altered the natural history of HIV infection, contributed to an increase in the number of persons living with AIDS, and changed the shape of the epidemic curves (see cover). As therapy has improved the health and prospects for AIDS-free survival among HIV-infected persons who receive these new treatment regimens, the ability of AIDS surveillance data to represent the characteristics of affected populations and project the need for resources for prevention and treatment has been diminished. This edition of the HIV/AIDS Surveillance Report marks a transition in how CDC will present HIV infection and AIDS data depicting the epidemic.
  
  AIDS surveillance data will no longer be adjusted to reflect the incidence of AIDS-OIs. The incidence of AIDS-OIs can no longer be estimated reliably because data are not currently available to model the increasing effects of therapy on the rate of disease progression. The procedure was developed to take into account the 1993 expansion of the AIDS case definition which had a temporary distorting effect on the AIDS incidence curve (see cover and technical notes). Because of these limitations, the estimates of AIDS-OI incidence in tables 18-20 will not be updated past the end of 1996. Instead, in future editions, CDC will publish estimates of AIDS incidence based on the incidence of all AIDS-defining conditions included in the 1993 AIDS surveillance case definition. AIDS data will remain useful as a measure of severe HIV-related morbidity in the population and to represent populations in which treatments have failed or those which were not tested or treated prior to a diagnosis of AIDS.
  
  The proportion of AIDS and HIV infection cases initially reported without risk information has increased in recent years. Several factors have contributed to this increase, including the greater volume of cases after the change in the AIDS case definition in 1993, decreases in surveillance staff in some areas, and increases in heterosexual transmission to persons (especially women) without recognizable high-risk behaviors. In the past, areas that conducted both HIV infection and AIDS case reporting prioritized the completion of risk information for AIDS rather than HIV infection cases. Because of delays in completing these data, trends in incidence, deaths, and prevalence by risk/exposure category (tables 20, 23, 26) are presented using an estimation procedure that imputes risk for cases initially reported without risk information. The procedure is based on historical patterns of reclassification after epidemiologic follow up (figure 7). However, tables that present characteristics of reported AIDS cases (tables 3-8, 15, 17) and of reported HIV infection cases (tables 28-31) are not adjusted for delays in reporting risk/exposure data. The high percentage of recent cases that have no reported risk poses difficulties in interpreting the meaning of the proportionate distribution of cases by risk groups. No longer is it possible to compare differences in proportions by risk group for the current year to the previous year without estimating how the cases without risk information will eventually be reclassified. Therefore, in future editions of the HIV/AIDS Surveillance Report, tables that present risk data for HIV infection and AIDS cases will be revised to include adjustments for unreported risk in order to enable readers of the report to infer recent trends by risk group.
  
  The trend data for AIDS-OI incidence, deaths, and prevalence shown in tables 18-26 are adjusted for delays in reporting of cases and deaths (see Technical Notes). These adjustments have been routinely applied when presenting trends in AIDS surveillance data for many years, but not for HIV infection surveillance data. HIV infection case surveillance data are currently reported from most, but not all states (table 27) and the HIV infection and AIDS case reporting systems in these areas were only fully integrated in late 1993. Based on several years experience with delays in reporting of HIV infection cases, delay adjustments for these data have been developed recently. In future editions of the HIV/AIDS Surveillance Report, trends in the number of new diagnoses of HIV infection will be presented using these adjustment procedures to enable readers of the report to interpret more recent trends in the epidemic than are reflected in AIDS surveillance data.
  
  Most states and metropolitan statistical areas reported a decrease in the number of AIDS cases reported in 1997 compared to the number reported in 1996 (tables 1 and 2). Whereas HIV infection and AIDS incidence are unaffected by surveillance practices, the reporting of HIV infection and AIDS cases to state and territorial health departments can be affected by changes in staffing patterns, evaluation studies which may identify previously unreported cases, or other changes in state or local reporting practices. In addition to these effects, antiretroviral treatments are changing the types of facilities where infected persons may be diagnosed and treated. Reporting areas are experiencing a shift in AIDS case reporting from hospital inpatient to outpatient settings. Areas that rely principally on case finding in hospitals may be missing cases. To ensure that persons eligible to be reported as HIV infection or AIDS cases are accurately represented in the surveillance data, it is increasingly important that states and territories implement uniform laboratory reporting methods to ascertain AIDS cases that meet immunologic criteria and HIV infection cases for those states that conduct HIV infection case reporting. To interpret unusual patterns in the number of cases reported in some geographic areas, readers of the HIV/AIDS Surveillance Report should consult the surveillance staff of the appropriate state or territorial health department.
  
  Since the beginning of the epidemic, CDC has published data on the number and characteristics of AIDS cases reported to CDC by state and territorial health departments. Initially, data were published weekly to help track this previously unrecognized and rapidly burgeoning health threat. Epidemiologic data quickly identified the ways in which the epidemic was spreading and the populations that were at greatest risk of HIV infection. With an increasing number of cases, detecting changes in geographic, demographic, and risk/exposure trends required longer periods of time, and the AIDS data publication schedule was revised to monthly, then quarterly, then semiannually. The ability of AIDS surveillance data to accurately depict the distribution and characteristics of affected populations led to a reliance on these data to describe the epidemic, identify populations in need of HIV prevention programs, and target and allocate resources for medical and other services for infected persons. However, because treatments have affected AIDS incidence rates among infected persons, CDC has stated that all states should implement HIV infection case surveillance as an extension of their AIDS surveillance programs. HIV diagnoses are not affected by treatment. Although all infected persons in the population may not seek or be offered HIV testing, the number of persons diagnosed with HIV infection together with AIDS diagnoses provides a reliable minimum estimate of the number and characteristics of persons who have accessed testing or care. CDC estimates that the majority of infected persons in the U.S. have been tested. The proportion tested among infected persons in the population is expected to increase. Accordingly, integrated HIV infection and AIDS case surveillance data will be useful in planning and evaluating prevention and treatment program needs and outcomes.
  
  While the number and characteristics of reported cases of HIV infection and AIDS in this edition remain useful as a minimum estimate of the characteristics of persons in need of services and treatment, the HIV/ AIDS surveillance system must evolve to meet public health needs for data in a changing epidemic. CDC and state and territorial health departments are currently revising HIV infection and AIDS case finding and reporting methods, changing how surveillance data will be analyzed and presented, and shifting the focus of surveillance program activities from AIDS to HIV infection including AIDS in order to be consistent with current public health recommendations for early voluntary testing, diagnosis, and treatment of HIV-infected persons.
  
  
• Content Notes:
  Publication date approximated.
• Subjects:
  Acquired Immunodeficiency Syndrome Acquired Immunodeficiency Syndrome / Epidemiology Data Interpretation, Statistical Epidemics Epidemiological Monitoring HIV Public Health Surveillance Statistics Tables
• Keywords:
  DHP_HIV_Reports
• Series:
  HIV Surveillance Report
• Subseries:
  HIVSR
• Publisher:
  Centers for Disease Control and Prevention (CDC) (U.S.)
• Document Type:
  Text
• Genre:
  Statistics ; Report
• Place as Subject:
  United States
• Rights:
  Public Domain
• CIO:
  National Center for HIV, STD, and TB Prevention (NCHSTP)
• Division:
  DHPSE - Division of HIV/AIDS Prevention — Surveillance and Epidemiology
• Topic:
  Diseases & Conditions
• Location:
  North America
• Pages in Document:
  43 pdf pages
• Volume:
  9
• Issue:
  2
• Citation:
  Suggested Citation: Centers for Disease Control and Prevention. HIV/AIDS Surveillance Report, 1997;9(No. 2):[inclusive page numbers].
• Collection(s):
  Infectious Diseases Stephen B. Thacker CDC Library
• Main Document Checksum:
  urn:sha-512:7986226858a4cce22b5e3eae0decda7606ad8e40d970602dd4d806a750d264b2fc429b27b257b06fb12c94b2b1eca0c0438abb05a0a50d743f11ade4e9283212
• Download URL:
  https://stacks.cdc.gov/view/cdc/34399/cdc_34399_DS1.pdf
• File Type:
  [PDF - 672.15 KB ]