Factors contributing to the decline of leprosy in Spain in the second half of the twentieth century.

BACKGROUND Leprosy is a chronic infectious disease that is considered to be declining, though it still remains prevalent in many parts of the world. A study was made to explore the health and socioeconomic factors that most influenced the trend of the disease in a typical Mediterranean country. MATERIALS AND METHODS An ecological study was conducted, investigating possible social, economic and health factors related to the evolution of leprosy incidence. The time period considered was 50 years--the second half of the twentieth century in Spain. RESULTS The variables showing the strongest correlation to evolution of the incidence of the disease were employment, the number of physicians, and the gross domestic product (GDP), with negative coefficients--while tuberculosis showed a positive coefficient. However, the GDP showed the highest coefficient (0.5). The model that best explained the evolution of leprosy over the last 50 years comprised a 6-year lag period between the socioeconomic factors and the incidence of leprosy--explaining 57% of the data obtained. The annual decrease in leprosy incidence was 1.6%. CONCLUSIONS Socioeconomic development, assessed in terms of the GDP, was the most important factor in explaining the evolution of leprosy incidence.