[An estimation of the prevalence of hanseniasis by research in non-specific demand for health services].

In view of the importance of knowing the prevalence and incidence rates of a disease to learn about its behavior and control at the collective level, a study was undertaken to determine the occurrence of hanseniasis among the clients of health agencies and to explore the use of this methodology for estimating the epidemiologic "iceberg" of the disease, i.e., the total number of cases including those that are not officially reported. The city of Taubaté in the Paraíba Valley, State of S. Paulo, Brazil, was chosen for the study. All clients aged 15 years or older were screened regardless of variables such as sex, age, social condition or marital status. The study was based on what is known about the populational distribution of the disease and the characteristics of health services. In view of the local peculiarities of operationalization (e.g., identity of the different clientele, availability of offices, hours of greatest flux), the sampling process used was simple randomization. The patients with active disease detected, 40 of the 10,013 persons examined, correspond to a prevalence of 3.99/1000, with a confidence interval (at the 5% level of reliability) of 3,365 to 4,625/1000, indicating that the minimum estimated increase of prevalence is of the order of 52% and the maximum estimated increase is of the order of 109%.(ABSTRACT TRUNCATED AT 250 WORDS)