New Americans remember when malaria plagued the United States. In the early 20th century, officials fought to control the disease — especially in the South — by studying transmission and targeting mosquitoes. Cases fell from 15,000 in 1947 to just 2,000 in 1950, leading the CDC to declare malaria eliminated in 1951. Yet the Anopheles mosquitoes that carry malaria still exist throughout the continental United States.
Increased international travel during the 21st century has made it necessary for scientists, healthcare providers and public health professionals in the United States to maintain watch against malaria and other deadly infections, said Tuan M. Tran, MD, PhD, a physician-scientist in the Division of Infectious Diseases who studies immunity to malaria.
"We have to remain vigilant and continue to study these infectious diseases that can emerge or re-emerge within the United States, especially since our climate has become ideal for the mosquitoes that spread malaria and other infectious pathogens to thrive," Tran said. He added that infected travelers returning from a country where malaria is common could lead to local outbreaks of the disease in the United States similar to what happened in the summer of 2023.
The Tran Lab at IU School of Medicine investigates the immune system by applying multiomic technologies to biological samples from malaria-exposed individuals. His research aims to explain how the body protects itself from malaria and how the immune system works to fight it off.

Tran began malaria research as an MD/PhD student at Emory University. He completed his residency in internal nedicine at the Johns Hopkins Hospital in 2010 and then a fellowship in infectious diseases at the National Institutes of Health in 2015. During his fellowship, he studied the human immune response to malaria and developed his skills in bioinformatics analysis.
Now, Tran and his research team at IU School of Medicine study all facets of malaria, from field studies where the children frequently suffer from malaria to experiments in the lab using human blood cells and the plasmodium parasites that cause the disease. In recent years, they have made important observations on how low-level inflammation may help lessen the impact of malaria infections in young children in sub-Saharan Africa who face a constant barrage of infectious mosquito bites every single day.
As malaria continues to be a major public health issue and causes severe illness in thousands of young children across the globe every day, Tran knows their efforts are as important as ever.
"At the top levels, you have the ecological and socioeconomic factors that affect the behaviors of the primary vector for transmitting malaria, female Anopheles mosquitoes, and its obligate vertebrate hosts, including us humans. Then there is still so much to learn about the biology of single-celled malaria parasites and how they interact with their mosquito and human hosts at the molecular level," he said. "These reasons challenge me to come up with important questions that, if successfully answered by our work, may lead to solutions to reduce the burden of illness caused by malaria."