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.