[Application of a system of serological surveillance of Chagas disease in a region of high chagasic endemia. I. Prevalence of Trypanosoma cruzi infection in Salamanca].

A serologic study for prevalence of Chagas infection was performed in Salamanca, Northern Chile. Indirect immunofluorescence and indirect hemagglutination reactions were used in samples from 1529 females and 698 males representing 10% of the population. A total of 499 positive results were obtained. The incidence of infection increases at a mean rate of 1% per year up to age 30, declining slowly in older groups to reach a maximum of 39.7% for the population. These data will be used to implement appropriate serologic surveillance programs and sanitary control measures in this and other populations.