Clinical diagnosis of malaria on the Thai-Myanmar border.

BACKGROUND: To evaluate the prevailing practice of presumptively diagnosing malaria in all cases of febrile illness in a clinic serving a refugee population on the Thai-Myanmar border METHODS: A retrospective review of 3,506 patient charts from December 1993 through June 1994 at the MaeSot medical clinic to compare clinical signs of malaria to blood smear findings. Patients presenting without fever were assumed not to have malaria; the remaining 2,111 patients presenting with fever had blood smears examined for malaria infection. RESULTS: Fever alone sufferedfrom poorpositive predictive value (54.7 percent) and specificity (59.3 percent). When fever was combined with hepatosplenomegaly and anemia, the positive predictive value and specificity improved (84.5 percent and 98.5 percent, respectively). However, this combination also resulted in an unacceptably poor sensitivity (16.5 percent) and false negative error rate (835/1,000). CONCLUSIONS. In this nonimmune refugee population, severe complications of falciparum malaria occur quickly and commonly; aggressive chemotherapy is necessary to reduce morbidity and mortality. Until laboratory facilities are made available, all cases offever should continue to be treated presumptively as malaria.