MALARIA - HOW USEFUL ARE CLINICAL-CRITERIA FOR IMPROVING THE DIAGNOSIS IN A HIGHLY ENDEMIC AREA

To assess the validity of clinical criteria, we investigated 2096 outp atients diagnosed as malaria cases by nurses at a rural health subcent re in a highly endemic area of Papua New Guinea. 73% of the children < 10 years old had a positive blood slide for any species of Plasmodium and 32% had greater than or equal to 10 000 P. falciparum parasites pe r mu L. For adults the frequencies were 51% and 9%, respectively. Step wise logistic regression identified spleen size, no cough, temperature , no chest indrawing, and normal stools as significant predictors for a positive blood slide in children; no cough and normal stools predict ed a positive blood slide in adults. Fever, no cough, vomiting, and en larged spleen were significant predictors for a P. falciparum parasita emia greater than or equal to 10 000/mu L in children; in adults the o nly predictor was vomiting. In children the association of no cough an d enlarged spleen had the best predictive value for a positive blood s lide, and a temperature greater than or equal to 38 degrees C had the best predictive value for a P. falciparum parasitaemia greater than or equal to 10 000 mu L. In adults, no major symptom had a good predicti ve value for a positive blood slide but vomiting had the best predicti ve value for a P. falciparum parasitaemia greater than or equal to 10 000/mu L. When microscopy is not available, these findings can help in areas of high endemicity to determine which patients with a history o f fever are most likely to have malaria and, more importantly, for whi ch patients another diagnosis should be strongly considered.