Malaria risk in travelers.

Imported malaria has been an increasing problem in several Western countries in the last 2 decades. To calculate the risk factors of age, sex, and travel destination in Swedish travelers, we used data from the routine reporting system for malaria (mixture of patients with and without adequate prophylaxis), a database on travel patterns, and in-flight or visa data on Swedish travelers of 1997 to 2003. The crude risk for travelers varied from 1 per 100,000 travelers to Central America and the Caribbean to 357 per 100,000 in central Africa. Travelers to East Africa had the highest adjusted odds ratio (OR = 341, 95% confidence intervals [CI] 134-886) for being reported with malaria, closely followed by travelers to central Africa and West Africa. Male travelers as well as children <1-6 years of age had a higher risk of being reported with malaria (OR = 1.7, 95% CI 1.3-2.3 and OR = 4.8, 95% CI 1.5-14.8) than women and other age groups.