For anyone who's ever suspected that flu spreads more easily in certain kinds of climes than others, you may be on to something.
The National Institutes of Health's Fogarty International Center and the University of Arizona discovered that flu epidemics tend to be associated with humid and rainy climates or cold and dry climates, according to a recent study in the journal PLoS Pathogens. Through these findings, researchers said that areas with these climes could better prepare themselves for flu season.
“The model could have a broader application, encouraging researchers to analyze the association between climatic patterns and infectious disease across a wide range of diseases and latitudes," study researcher Cecile Viboud said in a statement.
The researchers used a global database to examine virus activity in 78 sites from 1975 to 2008. This information provided insight into when the virus appeared most frequently, a phenomenon known as "influenza peaks," according to the study. The researchers also compiled data from other published surveillance studies on the flu and respiratory viruses.
In addition to collecting data from the 78 sites around the world, the researchers also included epidemiological information from Spain, Tunisia, Senegal, Philippines, Vietnam, Colombia, Paraguay, South Africa and Argentina. The nine countries had participated in FluNet, the World Health Organization's global influenza surveillance program.
Viboud and colleagues discovered that temperature and specific humidity were the best indicators of influenza peaks.
"Anecdotal evidence suggests that colder climates have winter flu while warmer climates that experience major fluctuations in precipitation have flu epidemics during the rainy season, and the current study fits that pattern," Viboud said in the statement. "In contrast, the seasonality of influenza is less well-defined in locations with little variation in temperature and precipitation and is a pattern that remains poorly understood."
The models the researchers devised managed to predict the timing of peak flu activity with 75 to 87 percent accuracy.
The researchers believe that the next step is to explore other factors that can influence the spread of influenza, such as specific environments, demography, and even travel.
Flu is not the only health issue that seems to be connected with climate. HuffPost Green reporter Lynne Peeples recently reported on a link between Lyme disease and precipitation and temperature changes from climate change.