[Evaluation of the demand for tests for the detection of anti-human immunodeficiency virus antibodies in Catalonia].

BACKGROUND: Most programs for the control of the acquired immunodeficiency syndrome (AIDS) contemplate the registry of cases as the principal source of information. Despite the fact that these data have permitted important epidemiologic and clinical aspects of the disease to become known epidemiologic surveillance systems should be developed based on the detection of infection by the human immunodeficiency virus (HIV). METHODS: The prevalence and the epidemiologic profile of patients who underwent an anti-HIV test were studied in 17 hospitals in Catalonia in 1989. In addition, a questionnaire concerning demographic and epidemiologic variables was completed by all the patients in whom an ELISA test had been carried out during 4 periods of 15 days. RESULTS: During this period 33,012 serologic tests were performed in 17 centers with a global prevalence of positive results of 20.7% (IC 95% = 20.2%-21.1%). The greatest number of positive serologies corresponded to the collective of intravenous drug users (IVDU), consisting of 68% of all the positive tests with a prevalence of infection of 76.4%. Prevalence was considered as constant throughout the year despite the differences between the prevalence observed in some periods. CONCLUSIONS: The fact that the collective of intravenous drug users is most prevalent among the patient with positive results in the serologic detection of the human immunodeficiency virus (HIV) confirms that this is the principal group of transmission in Catalonia. This type of study may provide information on the rate of infection by HIV complementing other surveillance methods of the epidemic. However, the basic function of these tests stems from the study of the demand and use of detection tests.