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1998; 91: 56-60

**10** 

*USA* 

**Malaria Chemoprophylaxis for the** 

 **International Traveler, Current** 

*Uniformed Services University of the Health Sciences* 

Ross Parker and Kevin Leary

**Options and Future Possibilities** 

Malaria remains the most important parasitic disease in the world, causing approximately 250 million infections annually and one million deaths, mostly in African children. International travelers are at risk of developing malaria when visiting endemic regions, and account for an estimated 30,000 cases of malaria annually (World Health Organization, 2011). The parasite is transmitted by the female Anopheles mosquito and is caused by four protozoa of the *Plasmodium* genus *(P. falciparum, P. vivax, P. ovale* and *P. malaria)*. *P. falciparum* causes the most significant disease burden with the highest morbidity and mortality. In addition to mosquito control and avoidance measures, chemoprophylaxis remains a critical component for preventing malaria infection in non-

Addressing malaria chemoprophylaxis for the international traveler can be challenging. In addition to patient-specific factors, the provider must consider a wide array of other variables, such as the predicted risk of malaria associated with the destination, type and duration of exposure during the trip as well, as the profile of the drug being prescribed. Seasonal, geographic, and climate are among the environmental variables that should be addressed to appreciate risk of malaria transmission. There can be upwards of a 200-fold difference in relative risk of contracting malaria depending on geographic variables for the international traveler, with sub-Saharan Africa conferring the greatest risk (Leder et al., 2004; Freedman, 2008). The traveler's accommodations, anticipated understanding and adherence to mosquito avoidance and control measures, chemoprophylaxis and access to appropriate medical care

Patient-specific variables can also present challenges to the provider. Pregnant, nursing and pediatric travelers present unique considerations when determining the most appropriate chemoprophylactic regimen. Pregnant patients incur a much higher risk of mortality and morbidity from malaria than non-pregnant travelers, and require extensive counselling on the risks and benefits of proposed travel to areas at risk of transmission. Emerging parasite drug resistance patterns, side-effect profiles, both long and short term, contraindications and poor adherence are additional challenges that need to be considered when selecting an appropriate antimalarial chemoprophylactic agent. In addition, how to address chemoprophylaxis in long-term travelers, generally defined as travel greater than six-

contribute to the risk of morbidity and mortality associated with malaria.

**1. Introduction** 

immune travelers.
