Study of coinciding foci of malaria and leptospirosis in the Peruvian Amazon area.

A hyperendemic malaria focus, found in 1973 in a secluded valley in South-eastern Peru, was restudied in 1975. Tests for antibodies to Plasmodium and Leptospira were performed on blood serum and blood slides collected at three locations on the Rio Ene and confluent streams and at two locations in the neighbouring highlands. The hyperendemic focus of P. vivax-P. malariae found at Mission Cutivirini in 1973 was confirmed in this study. Another hyperendemic focus of predominantly P. vivax was found at the village of Saoreni. Lesser amounts of malaria were found at other locations. Serology indicated past or present contact with Leptospira of from 50 to 75% of individuals at all locations. The two hyperendemic malaria foci therefore were embedded in a much larger hyperendemic focus of leptospirosis. The value of the indirect immunofluorescence test for malarial antibodies as a sero-epidemiological tool was emphasized by this study.