Diagnosis of malaria in the febrile traveler.

To determine if clinical presentation can be used for predicting malaria infection in febrile patients with recent travel to a malaria-endemic area, 157 patients with malaria, a history of fever, and recent travel to a malaria-endemic area were compared with 157 matched controls in case-control study. Fever pattern, symptom duration, temperature, splenomegaly, and platelet count were correlated with malaria infection. These criteria, however, either singly or in combination, had low sensitivity for accurately identifying patients with malaria. Because no criterion could accurately predict the presence of malaria, it is concluded that microscopic examinations of blood for malaria parasites should be done in all symptomatic patients with a history of travel to a malaria-endemic area.