When a doctor suspects a patient has malaria, the next step is usually a blood test. Most commonly, a technician smears a drop of blood on a slide and examines it under a microscope for tell-tale signs of the parasite.
But preliminary research from Washington University suggests future malaria testing could be as simple as collecting a breath sample.
The study, published in the February issue of The Journal of Infectious Diseases, reports malaria-infected children in Malawi show a distinct shift in the compounds in their breath compared to healthy children. Based on the abundance of six compounds, the researchers were able to diagnose malaria infection with 83 percent accuracy.
Importantly, breath differences between infected and uninfected children were consistent even after controlling for potential complicating factors such as sex, age and malnutrition.
“It’s really been a very exciting result for the lab,” said Audrey Odom John, Washington University associate professor and study co-author. “I think there was some jumping up and down involved.”
The need for a new diagnostic test for malaria may become more urgent. According to the World Health Organization, there were an estimated 216 million new cases and 445,000 malaria-related deaths in 2016. Meanwhile, a common blood test for diagnosing malaria, the rapid diagnostic test (RDT), is becoming less effective.
“The malaria parasite has stopped making the protein that is detected in [the rapid diagnostic] test,” said Odom John. The predictions are in the next 20 to 25 years there is probably going to be widespread ability of the parasite to avoid being diagnosed.”
Despite the need for a new test, the results are just the first step in developing a breath test for malaria.
“In order to ultimately have a real breathalyzer test for malaria, we need to see if these results hold true in other populations,” Odom John said. “Do they hold up in adults as well as children? Do they hold up in children with severe malaria, not just uncomplicated malaria?”
The research team plans to expand the study to populations in Malawi and Kenya.