Even weak tropical cyclones raise infant mortality in poorer countries, USC-led research finds

By A Representative 

Even tropical cyclones that fall below hurricane or typhoon strength significantly increase infant mortality in low- and middle-income countries, according to new research led by the University of Southern California and published in Science Advances. The study, covering the first two decades of this century, found that exposure to such storms raised infant deaths by an average of 11%—or 4.4 additional deaths per 1,000 live births—in economically vulnerable nations.

The research team, which included scholars from USC, RAND Corporation, Stanford University, Johns Hopkins University and UCLouvain in Belgium, discovered that the elevated mortality was most pronounced in the first year after a storm. Surprisingly, typical explanations such as reduced access to prenatal care or increased undernutrition did not account for the rise in deaths. “The fact that health care use and undernutrition were not affected by tropical cyclone exposure suggests that the mortality effects are driven by other factors that we could not directly study,” said lead author Zachary Wagner, associate professor at USC Dornsife College and senior economist at the Center for Economic and Social Research.

The study examined data from nearly 1.7 million children in seven lower-income countries—Madagascar, India, Bangladesh, Cambodia, the Philippines, the Dominican Republic and Haiti. The effects of storms varied widely across nations. Bangladesh, Haiti and the Dominican Republic experienced the most severe increases in infant deaths, with more than 10 additional deaths per 1,000 births following cyclones. By contrast, India, the Philippines, Cambodia and Madagascar showed little to no change in mortality. The researchers suggest these discrepancies may stem from differences in geography, housing, healthcare infrastructure and disaster preparedness.

“Some countries may be helped by mountains while others have more flood-prone areas,” Wagner noted. “And in some places, children may already be malnourished or in poor health from malaria and other diseases, which increases vulnerability.” Wagner said a key focus going forward will be to understand why some countries fare better than others.

“As the planet warms, we risk more tragedies across the globe if measures aren’t taken to protect children in the poorest countries,” added Zetianyu Wang, a PhD student at RAND and first author of the report.

The study was supported by the National Institute of Child Health and Development under grant number R01HD104835.