Emergency department presentation and misdiagnosis of imported falciparum malaria

Abstract

Study objective: To review the travel history, clinical presentation, laboratory findings, diagnostic accuracy, management, and outcome of the largest reported series of emergency department patients with imported falciparum malaria in the United States.

Methods: This is a retrospective case series at large, inner-city medical center in Los Angeles. Twenty cases of falciparum malaria with initial medical evaluation in the ED were identified from the period 1979 through 1993.

Results: Fifteen male and 5 female patients were identified, with an age range of 5 to 55 years. All had a recent history (within 2 months) of international travel in regions endemic for malaria. Most (85%) were recent immigrants or expatriates returning from a recent visit to their native country. The most common documented symptoms were fever (100%), chills (65%), vomiting (60%), anorexia (45%), and headache (45%). Tachycardia (85%) and hyperpyrexia (> 39 degrees C) (65%) were the most common presenting signs. Malaria was considered in the ED diagnoses in only 12 cases (60%). The specification of falciparum (malignant) malaria was established in only 2 cases (10%). Hepatitis and gastroenteritis were the most common misdiagnoses. Only four patients received antimalarial medication in the ED. There were no deaths, and complications were limited to thrombocytopenia and anemia. Two patients required transfusion.

Conclusion: Imported falciparum malaria presenting to EDs in the United States is frequently misdiagnosed. Emergency physicians improve their ability to diagnose falciparum malaria by obtaining a thorough travel history on all patients with clinical features suggesting an infectious origin and considering this diagnosis in any patient with a history of travel to or migration from malaria-endemic areas.