A sudden drop in outdoor temperature increases the risk of respiratory infections
You can pretty much put a mark in your calendar for when the annual flu epidemic begins. Using 20,000 virus samples and weather statistics, researchers have now discovered more details about how outdoor temperature and flu outbreaks are linked.
“According to our calculations, a cold week with an average temperature below zero degree Celsius precedes the start of the flu epidemic” says Nicklas Sundell, a researcher at Sahlgrenska Academy and infectious diseases specialist at Sahlgrenska University Hospital.
The study comprised three seasons and 20,000 virus samples taken with nasal swabs from people who sought medical care in the Gothenburg area. The incidence of respiratory viruses was then compared over time with weather data from the Swedish Meteorological and Hydrological Institute (SMHI) and the results are clear: Flu outbreaks seem to be activated about one week after the first really cold period with low outdoor temperatures and low humidity.
Kickstarting the epidemic
“We believe that this sudden drop in temperature contributes to “kickstart” the epidemic. Once the epidemic has started, it continues even if temperatures rise. Once people are sick and contagious, many more may become infected,” says Nicklas Sundell.
Continue reading at University of Gothenburg.
Photo via University of Gothenburg.