A bacterial disease you’ve probably never heard of could be responsible for almost 90,000 deaths each year, a new analysis suggests. And though the bacterium was previously thought to reside mostly in Southeast Asia and Northern Australia, scientists now say it could be present in nearly 80 countries across the world.
Melioidosis is caused by the bacteria Burkholderia pseudomallei, which is typically found in soil and can infect people when inhaled or through cuts and sores on the skin. It is naturally resistant to many antibiotics. The disease’s fatality rates can surpass 70 percent in some areas, partly because it is very difficult to diagnose.
In a study published Monday in Nature Microbiology, researchers found that melioidosis cases likely occur in 34 countries in the Middle East, Africa, and South America that have never documented a case. The disease is also “severely underreported” in the 45 countries with reported cases, particularly in South Asian countries, the study found.
Though the bacterium is likely not in US soil now, scientists found that the climate of Florida, Louisiana, and Texas would likely support the microbe if it was introduced.
To predict where in the world the bacteria live, the researchers developed a model based on reported cases, soil characteristics, and other geographic factors. Once they had their map, they estimated the number of melioidosis cases and deaths based on existing epidemiological data.
Many countries that might see melioidosis lack the microbiological facilities to identify the bacteria, said Direk Limmathurotsakul, the lead author of the study and a researcher at Mahidol University in Bangkok and the University of Oxford. A lack of knowledge about the disease and flawed reporting systems in parts of the developing world also contribute to the underreporting problem, he said.
The researchers’ revised estimate finds that 165,000 people may have been infected with melioidosis in 2015, and that 89,000 could have died. In comparison, measles killed 115,000 people in 2014, according to the World Health Organization.
Limmathurotsakul said the authors hope policymakers in countries at risk for melioidosis cases improve their ability to diagnose the disease and their overall disease reporting systems. That could lead to prevention campaigns to stop new cases, he said.
“With those, the mortality caused by this deadly disease could be reduced worldwide,” he wrote in an email.
Bart Currie, an infectious diseases professor at the Menzies School of Health Research in Australia who was not involved with the study, called the analysis “excellent” but said the figures now need real-world verification.
“One possibility that further studies may show is that the bacteria may not yet have spread to all the predicted areas,” Currie wrote in an email. “If that is the case, then the predicted numbers and deaths may not be at the level found in the modeling.”
Currie said it is unclear whether melioidosis is increasing as a global health problem or keeping stable. But one worrying trend: Diabetes is growing in the developing world, and people with diabetes are more susceptible to melioidosis.