Leishmaniasis in Central Brazil: Results of a Montenegro skin test survey among Amerindians in the Xingu National Park

74% of the population (540) of 8 tribes of protected Amerindians in the Xingú National Park of Brazil were skin tested with Montenegro antigen and examined for lesions due to Leishmania braziliensis. No active primary lesions or evidence of secondary mucocutaneous involvement were found. Old scars from primary lesions due to an epidemic of leishmaniasis in the Waurá tribe between 1962 and 1964 were examined, and possible causes for this outbreak are discussed. 76% of all males and 47% of all females gave positive Montenegro reactions, and all Indians by the age of 40 were found to have evidence of skin sensitivity to the antigen. The high rate of infection was found to be constant over the whole region studied. Important differences in the rates of infection in succeeding age groups of males and females appear to correlate with differing activities within the tribe of the two groups, and suggest that the major source of infection is beyond the confines of the village.