Characteristics and Severity of Disease among 100 Cases of Imported Malaria Seen at a U.S. University Hospital, 2000-2017.

Malaria acquired in endemic areas poses a substantial risk to travelers arriving in or returning to the United States. Timely diagnosis and recognition of severe illness are crucial; however, many U.S.-based clinicians lack familiarity with this disease. We conducted a retrospective review of 100 cases of malaria in adults seen at a single urban university hospital during 2000-2017. Descriptive and analytical statistics were calculated, including logistic regression modeling case severity. Most of the patients presented with Plasmodium falciparum (76%), most commonly after travel from sub-Saharan Africa (94%). Prior malaria experience was common (50%), but adherence to a prophylactic regimen was exceedingly rare (4%). Twenty-one patients had severe malaria, including 10 with cerebral malaria. Severity was predicted by high parasitemia, bandemia, hypoglycemia, and hypotension at the time of presentation. In 24 patients, the initial treatment regimen was changed, usually because of the appearance of clinical deterioration or drug toxicity. One patient required intravenous artesunate. All patients survived, although one suffered fetal loss. Among 30 patients initially evaluated at other institutions, 43% had been treated for an alternative diagnosis. The most common reasons for transfer of patients to our hospital were inadequate facilities and lack of expertise with malaria. There needs to be increased awareness among U.S.-based travelers and clinicians regarding malaria as a potentially lethal condition, emphasizing the use of appropriate prophylaxis. Our simple model of disease severity could serve frontline physicians when deciding which patients should be admitted to the intensive care unit or transferred for higher level care.