Background: 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.
Methods: 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.
Results: 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 (OR: 19.7; 95% CI: 2.2–174.6) and hepatomegaly (OR: 6.1; 95% CI: 1.1–32.8) 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.
Conclusions: 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.