Epidemiologic features impacting the presentation of malaria in children in Houston.

Malaria is diagnosed in children in the United States despite availability of effective chemoprophylaxis. The features impacting the presentation of malaria diagnosed in a nonendemic setting are not well characterized in children.

A retrospective chart review was conducted of children with peripheral smear-confirmed malaria diagnosed from 1994 to 2007 at 4 tertiary referral hospitals in Houston, TX.

Among 104 children with malaria, 43 were recent immigrants and 61 were travelers leaving the United States. Severe malaria accounted for 21 (20%) of episodes. Children residing in the United States accounted for 86% of those with severe malaria. Factors relating to malaria severity included vacation-related travel (P = 0.005), female gender (P = 0.02), birth in the United States (P = 0.043), short travel duration (P = 0.024), and short duration from return to presentation (P = 0.023). Children with severe malaria more often had a history of vomiting (P = 0.048) and presented with hepatomegaly (P = 0.008), heart murmur (P = 0.041), and higher parasitemia (P < 0.001) than those with uncomplicated malaria. Vacation-related travel (aOR 7.6; 95% CI 1.4–61.5), admission hemoglobin (aOR 0.6; 95% CI 0.4–0.8), and admission platelet count (aOR 1.0; 95% CI 1.0-1.0) remained significant risk factors for severity by multivariate analysis. Prophylaxis appropriate to region of travel was documented in only 8 of 47 children leaving the United States.

Children diagnosed in Houston with severe malaria usually had traveled from the United States to malaria-endemic regions without benefit of appropriate prophylaxis. Malaria-related morbidity in nonendemic countries could potentially be reduced by optimizing adherence to prophylactic regimens.