Time trends of Hansen's disease in Brazil

In an analysis of the trend of Hansen's disease in Brazil, the "incidence register" or "detection rate" per 100,000 was used. The operational data analyzed were presumed to be related to true incidence because of the time elapsed (38 and 19 years) and because of the large number of cases. The statistical method used was the exponential curve fit. From 1950 to 1987, there was an average annual decrease in the rate of 3% as indicated by the regression coefficient (slope), but from 1969 to 1987 an increase of 6% per year was observed. If this last trend is sustained, the detection rate in the year 2000 will be 35.03 per 100,000 or, in a population estimated as 190,000,000 inhabitants, 66,600 new cases. For comparison, in 1983 there were 18,759 new cases registered. The trend analysis for each of the Brazilian political-administrative areas (states and territories) is more accentuated in the Center-West and Northeast Macroregions, with a slope of 8% and 10%, respectively. In some states, such as Paraiba, Rio Grande do Norte, and Alagoas, there were astonishingly positive slopes of 20%, 18% and 17%, respectively. The distribution of the new cases by clinical forms during most of the period studied (1969-1987) confirms the overall trends observed. There was an increase in the detection rate of the tuberculoid form of 5% annually--compared to the lepromatous (combined with borderline) rate of 3% per year--and, also, the increase in the tuberculoid form was greatest in the Center-West and Northeast Macroregions.(ABSTRACT TRUNCATED AT 250 WORDS)