Humphreys and Jane Ruseski, PhD, associate professor of economics at WVU, analyzed flu mortality data from the Centers for Disease Control and Prevention (CDC) between 1962 to 2016. They found that flu deaths increased by between 5 and 24 percent during the NFL, NBA, NHL, and MLB seasons, with the largest increase being during NHL season. The researchers looked at what happened with flu death rates when a city got a new professional sports team compared to cities that didn’t. “As it turned out, after a new professional sports team came into a city, that flu season and every flu season afterward had more people dying of the flu,” Humphreys said in a statement.ae0fcc31ae342fd3a1346ebb1f342fcb The report also showed a decline in flu deaths in U.S. cities during season stoppages, like during the 2011 NBA lockout and the 1982 NFL strike. RELATED: For more up-to-date information, sign up for our daily newsletter. As the potentially deadly COVID-19 contagion continues to spread throughout the nation, this data could hint that the coronavirus could see a further jump should fans return to stadiums. “Opening pro sports games to fans is probably a terrible idea, in terms of public health,” said Humphreys. “You’re right on top of people and everybody’s yelling, screaming, high-fiving and hugging. And you’ve got people eating and drinking. You could be putting the virus right into your mouth. The bottom line is we need to be very careful if we’re considering opening up games to the fans.” One of the things we know about the COVID-19 pandemic is that being in a crowded and poorly ventilated indoor environment—like arenas that host sporting events—are among the most dangerous. Also, the release of aerosolized droplets from yelling, chanting, or singing, which many fans do during a big game, significantly increases the risk of spread. “It isn’t one or two people dying. This is closer to 30 or 40 additional flu deaths over the course of flu season. When you blow it up to a virus that’s more fatal like COVID-19, we could be talking about hundreds of additional deaths because of these games,” Humphreys added. And for more on places that pose danger, check out These Will Be the Last Places to Reopen After the Coronavirus.