The American public can expect to add earlier and more severe flu seasons to the fallout from climate change, according to a research study published online Jan. 28 in PLOS Currents: Influenza.
A team of scientists led by Sherry Towers, research professor in the Mathematical, Computational and Modeling Sciences Center at Arizona State University, studied waves of influenza and climate patterns in the U.S. from the 1997-1998 season to the present.
"It appears that fewer people contract influenza during warm winters, and this causes a major portion of the population to remain vulnerable into the next season, causing an early and strong emergence," says Towers. "And when a flu season begins exceptionally early, much of the population has not had a chance to get vaccinated, potentially making that flu season even worse."
The current flu season, which is still in high gear in parts of the nation, began early and fiercely. It followed a relatively light 2011-2012 season, which saw the lowest peak of flu since tracking efforts went into effect, and coincided with the fourth warmest winter on record. According to previous studies, flu transmission decreases in warm or humid conditions.
If global warming continues, warm winters will become more common, and the impact of flu will likely be more heavily felt, say the study's authors.