Traveling for Work, Peruvian Migrants Sometimes Find Malaria

In the Maynas Province in northeastern Peru, few roads connect the small communities dotting the heavily forested region, and many people travel by boat to fish or work. But those trips also may be taking people to malarial hotspots, increasing their risk of infection.  

This is one of the key findings from thesis research done by Annika Gunderson, who graduated from DGHI’s Master of Science in Global Health program in 2021. Gunderson’s thesis was recently published in the Epidemiology and Infection journal. 

As a master’s student, Gunderson worked with a team of researchers to analyze data from an earlier survey of residents in the Maynas Province. Many men in the region work in logging or fishing, and researchers learned that these jobs often took them to remote areas where mosquitoes breed, increasing their risk of being bitten by mosquitoes that carry malaria parasites. 

“The results also showed people tend to travel more during the rainy seasons when there’s more water flowing through the rivers,” says Gunderson, who is pursuing a Ph.D. in epidemiology at The University of North Carolina at Chapel Hill. “It’s interesting to see the unique challenges of malaria in Latin America.” 

Bill Pan, DrPH, an associate professor of global environmental health at DGHI and The Nicholas School of the Environment, says Gunderson’s research helps document the malaria risk associated with traveling to remote parts of the province for work.   

“We were told by health care workers many malaria cases were from people returning from travel,” says Pan, who advised Gunderson’s research. “Our study confirmed this assumption.”  

Pan says the simplest approach to protecting workers from infection is prevention. For example, companies that purchase wood, oil, gold and other resources could call for better health standards for migrants working in those industries. “This includes interventions like providing insecticide-treated bed nets, supporting vector control in work camps and providing clothing or repellents to prevent mosquito bites,” he says.  

Gunderson adds that understanding the risks associated with migration could help identify workers for early treatment. 

Peru saw a decline in malaria cases in the early 2000s because of funded prevention programs. Once the funding stopped, cases began to rise in 2015 before slightly dropping prior to the COVID-19 pandemic, according to a 2022 report from the World Health Organization.  

Several factors contribute to the frequency of malaria outbreaks in the region, including climate change, deforestation and human migration, Pan says. The interconnection of those social and environmental factors is one reason Gunderson chose to study malaria for her thesis.  

“There’s a lot to take into account with malaria such as environmental factors and the mosquito-life cycle, which makes it more complex than other diseases,” she says. “You work with a lot of different people on this topic, which makes the work more interdisciplinary, and you learn more.” 

 Although COVID restrictions prevented Gunderson from traveling to Peru to conduct her research, she says working with data from the earlier survey taught her the imporance of fieldwork. 

 “You have to think about the assumptions you’re making and going to the field is important to draw accurate conclusions,” she says. “The beauty of observational studies are, in this case, when you understand where people travel and what they’re doing, you can better address it.”