[Effects of the 1987 revision of the definition for an AIDS case in Switzerland].

AIDS cases diagnosed in Switzerland after the revision of 1987 and reported to the Swiss Federal Office of Public Health until 31.12.1992 were categorised according to whether they conformed to the diagnostic criteria valid before the revision (= "pre-87"-group) or only to the new criteria introduced with the revision (= "post-87"-group). Compared to the "pre-87"-group, the proportion of injecting drug users was higher, the proportion of homosexual men was lower, the patients were younger and Pneumocystis carinii pneumonia (PCP) and Kaposi-sarcoma were diagnosed less frequently in the "post-87"-group. The revision of the AIDS case-definition affected the proportion of Aids-diagnoses with PCP over time. It improved the surveillance of AIDS morbidity in Switzerland but its effects must be distinguished from true phenomena of the AIDS-epidemic.