Accurate clinical diagnosis of malaria in a postflood epidemic: A field study in mozambique

Abstract

Objective - To determine the positive predictive value (PPV) of a clinical diagnosis vs laboratory testing for malaria in a remote field setting following a natural disaster. Methods - During an observational study, as part of a disaster response in Mozambique, patients were clinically diagnosed and treated for malaria. The population included native tribes in remote areas and displaced persons in refugee camps representing all age groups, male and female. The diagnosis was made if patients exhibited at least 3 of the following historical features: fever, chills, headache, and nausea/vomiting (N/V). In addition they had to have either a tactile fever or palpable spleen. At the conclusion of the mission, 28 patients were prospectively tested with an antigen-capture assay for P. falciparum to determine the PPV of clinical diagnosis vs definitive laboratory testing. Results - During the study period, 1215 of 4064 (30%) patients were diagnosed with malaria based on clinical presentation. On our final day, 28 consecutive patients with a clinical diagnosis of malaria were tested using an antigen-capture assay for P. falciparum. Of those, 25 tested positive - yielding a PPV of 89% (CI 0.78-1.01). Conclusion - In a remote field setting where malaria is endemic/epidemic, diagnosis of malaria based on selected historical and physical findings is possible with a high positive predictive value.