Fever of unknown origin and the role of Plasmodium vivax in Sao Paulo

Malaria is a disease that hits the northern part of Brazil in an endemic form. Recorded cases outside this region are unusual and, in most cases, limited to travellers. The southeast of Brazil has an extensive wilderness area with a type of vegetation similar to the one found in the equatorial rainforest. We present the case of a patient living in the southeast, with no reported travel history, who evolved to periodic fever, associated with myalgia and chills. With the positive test result for Plasmodium, the treatment for malaria was started. This case enabled the study in the Anopheles mosquito affected area, where the patient reported infection, outside the Amazon region.