World Malaria Day 2013: Travel and Malaria Infection in Ethiopia
Study Explores the Role Travel Plays in Malaria Infection in Ethiopia
Malaria remains the leading communicable disease and cause of morbidity in Ethiopia, with around one million clinical cases reported annually. Current methods to combat the disease—such as indoor residual spraying of households with insecticide and insecticide-treated mosquito nets—have proven to be highly effective at reducing exposure to infectious mosquito bites.
A recent report, co-authored by Richard Reithinger, an infectious disease expert at RTI, indicates travel may undermine control methods and complicate attempts to eliminate the disease by either maintaining or creating new sources of infection in areas where spraying, nets, and other interventions have lowered transmission rates.
The results were recently published in Malaria Journal.
As countries such as Ethiopia strive to eliminate malaria in areas of low transmission, the report suggests that careful consideration should be given to travelers, particularly mobile adult men, as they appear to be at a higher risk of infection.
The study was conducted at the Bulbula Health Center, a malaria epidemic detection and sentinel surveillance site in Oromia, as part of an ongoing collaboration between the U.S. President's Malaria Initiative, Tulane University, the Ethiopia Health and Nutrition Research Institute, and the Oromia Regional Health Bureau. The site serves as the primary health care facility in a market town that sees a significant number of migrant workers.
Over a period of 16 weeks, 560 patients (141 infected and 419 controls) were recruited for the study and then interviewed using a standard, pre-tested questionnaire covering socio-demographic and household risk factors for malaria, including recent travel history. Participants were questioned about overnight stays away from their home village within the prior 30 days and asked when and where they had traveled. Of these participants, 35 percent reported staying overnight outside their home village for at least one night. Travel was more common among men than among women.
The authors concluded that importation of infection due to travel may be key to maintaining transmission in areas of low endemicity. However, continued research will be needed to measure the proportionate effect such importation of infection to overall malaria transmission has in areas where transmission has been successfully lowered because of anti-malarial interventions.
The study results also indicated that increased risk of infection may arise from behavior changes coupled with travel, suggesting that communication strategies for travelers focused on prevention activities, including use of bed nets, may be beneficial in lowering infection risk.
"Although further investigation is needed," said Reithinger, "the findings indicate that in countries such as Ethiopia careful consideration has to be given to travelers and—in this case—specifically men so that efforts to reduce transmission are not undermined."