Prevention of malaria in long-term travelers.
BACKGROUND
Long-term travelers, defined here as those traveling for periods of 6 months or longer, face particular challenges regarding malaria prevention. Current guidelines for malaria prevention primarily address prevention of Plasmodium falciparum infections in short-term travelers.


OBJECTIVE
To examine the risk of malaria in long-term travelers, recent developments in personal protective measures, and the safety and tolerability of malaria chemoprophylaxis during long-term use and to consider prevention strategies including continuous chemoprophylaxis, stand-by emergency self-treatment, seasonal prophylaxis, and strategies to prevent primary infection and relapses from P vivax malaria.


METHODS
Comprehensive search of scientific publications including MEDLINE via both OVID and PubMED for relevant studies and articles with a cutoff date of July 2006, using the search terms long-term travel and malaria prevention, long-term malaria chemoprophylaxis, and insect repellent and malaria. Additional references were obtained from searching the bibliographies of the selected articles, from dissertations, and from the proceedings of relevant conferences on travel medicine. There were no language restrictions.


RESULTS
Long-term travelers have a higher risk of malaria than short-term travelers. Long-term travelers underuse personal protective measures and adhere poorly to continuous chemoprophylaxis regimens. A number of strategies are used during long-term stays: discontinuation of chemoprophylaxis after the initial period, sequential regimens with different medications for chemoprophylaxis, stand-by emergency self-treatment, and seasonal chemoprophylaxis targeting high-incidence periods or locations. All strategies have advantages and drawbacks. Counterfeit drugs sold in countries endemic for malaria pose serious concern for long-term travelers who purchase their medications overseas. Vivax malaria causes significant illness in travelers, but relapses of vivax malaria are not prevented with the current first-line chemoprophylaxis regimens. Consensus guidelines are needed for prevention of malaria in long-term travelers.


CONCLUSIONS
Prevention of malaria in long-term travelers is a complex issue and requires expert advice from travel medicine specialists. Recommendations for prevention of malaria in long-term travelers must be individualized.
Chen
Lin H
LH
Travel Medicine Center, Division of Infectious Diseases, Mount Auburn Hospital, Cambridge, Mass 02238, USA. lchen@hms.harvard.edu
Wilson
Mary E
ME
Schlagenhauf
Patricia
P
D000465:Algorithms; D000962:Antimalarials / Q000627:therapeutic use*; D006801:Humans; D008288:Malaria / Q000175:diagnosis / Q000517:prevention & control*; D012306:Risk; D014195:Travel
D000962:Antimalarials