Ever wonder why your entire workplace seems to get sick around the same time each year? It turns out there's a way to pinpoint when you're most likely to catch the flu, and it has everything to do with the weather.
In a November 2016 study published in the Journal of Clinical Virology, researchers from the University of Gothenburg in Sweden took more than 20,000 samples from nasal swabs of people receiving medical care over three seasons. When those data were compared to weather statistics from the same time period, an obvious trend emerged: Flu epidemics spike right after the temperature goes below freezing.
Yes, it turns out that a sudden drop of temperature is a sign the flu is coming. The researchers found that flu outbreaks tend to happen about a week after the first super-cold snap of the year, accompanied with dry air and low temperatures. "We believe that this sudden drop in temperature contributes to 'kickstart' the epidemic," researcher Nicklas Sundell said in a statement. "Once the epidemic has started, it continues even if temperatures rise. Once people are sick and contagious, many more may become infected."
It isn't clear exactly why cold weather seems to start annual flu epidemics, but the researchers do have a theory: When the air is cold and dry, aerosol particles of the flu virus can travel and spread more easily.
So if you live in a region that gets chilly in the winter, once you have that first cold spell, be sure to start taking precautions, including getting a flu shot if you haven't already, washing your hands frequently, and always covering your mouth when coughing or sneezing.