Last winter was unseasonably mild across many parts of the country. More cities set record highs than record lows, and many climate areas still have not recovered from snow droughts. The mild weather had many are questioning if there was a correlation between the low reports of influenza virus infections across all 50 states. With this year's winter rapidly approaching, many may be wondering how the forecast will impact the upcoming flu season. However, much like the winter season, the flu runs in cycles.
According to the Centers for Disease Control and Prevention's (CDC) weekly influenza report, the virus' activity last season has remained low well into the start of winter. According to the trends seen over the last 30 years, flu infections pick up in January, peak in February then continue on into May. The flu follows its own natural cycle, and CDC experts say that there isn't much of a correlation between how severe the winters are and how the flu will spread.
"There's just no solid science around the issue of the weather and influenza," said Tom Skinner with the CDC's Influenza Center.
He explained that there are some factors of winter that can help spread the influenza virus. People end up in closer quarters with windows shut to try to keep the cold out. This leads to stagnant air that allows the virus to spread with greater ease from person to person. Beyond that, there isn't much of a proven correlation between why the flu cycle happens to naturally peak during winter months.
The winter months correspond with the flu season nationally. From Alaska to North Carolina to Arizona, areas with drastically different climates, last year's flu stayed in the minimal range through late January with only sporadic spreading of the disease. It maintained the same levels regardless of the different winter weathers.
This map from CDC.gov shows the intensity of influenza across the United States last January:
This map from CDC.gov shows the intensity of influenza across the United States at the end of this past December:
While the increased cold compared to last winter may help account for more people being in closer quarters, the spread of the virus across differing climate areas is not correlated to the weather itself.
As for the myth that you can get sick by going outside in cold air under-dressed or with your hair wet, there is very little merit. Cold air by itself cannot "make" you sick.
"Going outside without a coat won't make you catch a cold, not wearing your earmuffs won't give you an ear ache," said Geisinger Health Clinic physician Dr. Raymond Nungesser. "Influenza is a virus, and viruses are spread through either direct contact, like having someone who is infected coughing on you, or through indirect contact, such as touching dirty keyboards or doorknobs."
Dr. Nungesser advices that the best ways to prevent getting the influenza virus are to get a flu shot and to maintain good hygiene.
"Wash your hands, wash your hands, wash your hands," he advises.
Learn more about what you can do to help keep you and your family safe this cold and flu season.