title: Estimating the number of AIDS-defining opportunistic illness diagnoses from data collected under the 1993 AIDS surveillance definition.
abstract: 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.
authors.affiliation: National Center for HIV, STD, and TB Prevention-Surveillance and Epidemiology, Centers for Disease Control and Prevention, United States Department of Health and Human Services, Atlanta, Georgia 30333, U.S.A.
authors.forename: J M
authors.initials: JM
authors.lastname: Karon
authors.forename: T A
authors.initials: TA
authors.lastname: Green
authors.forename: D L
authors.initials: DL
authors.lastname: Hanson
authors.forename: J W
authors.initials: JW
authors.lastname: Ward
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000145:classification / Q000175:diagnosis / Q000453:epidemiology*; D000163:Acquired Immunodeficiency Syndrome / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D000293:Adolescent; D000328:Adult; D000368:Aged; D018791:CD4 Lymphocyte Count; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D011159:Population Surveillance; D014481:United States / Q000453:epidemiology