With the flu season intensifying, you have to wonder what happens to the viruses that cause the sickness the rest of the year? As it turns out, they migrate—not unlike birds. Here are 9 ways to prepare for the worst month of flu season.
“The flu season can begin as early as October in the United States and ends in March, with a peak in February,” explains Dr. Kola Dushaj, MD, FACP of CareMount Medical in Cortlandt Manor, New York. However, cases can still occur a month or two after. But the flu season also depends on where you happen to be. “In the southern hemisphere, where their winter coincides with our summer months, the flu season can run from June to September,” says Dr. Dushaj.
So in the same way birds fly south for winter, the flu virus migrates—though in the opposite direction. “Studies have been done to analyze the migration of seasonal influenza A viruses,” says Dr. Dushaj. “After studying genomes from both southern and northern hemispheres, research reveals that cross-hemisphere migration frequently occurs and it can occur in both directions.” Plus, thanks to our modern modes of international travel and delivery of goods, says Dr. Dushaj, the flu virus can easily hitch rides around the world.
How does the flu stay alive?
The only way for viruses to survive and spread is to infect people (and animals). “Outside of a host, the virus lifespan is shortened. The influenza virus can live on some surfaces for up to 48 hours,” explains Dr. Dushaj. Because research suggests that colder weather favors a virus’s ability to survive, it travels in hosts to hospitable climates—winter—where it can more easily spread, he says. Find out 20 more things the flu virus doesn’t want you to know.
A study from 2007 showed the flu’s migration (and season) is based on humidity and temperature. “The flu virus tends to infect more people during cold and dry weather,” says Dr. Dushaj. Other conditions that encourage the spread of a virus may be staying indoors with sealed windows and recirculated air—as we do in winter. This increases the risk of inhaling the same air as someone who may have the flu, he says.
There are other theories on why the flu is worse in winter, says Dr. Dushaj: “Less sunlight exposure in the winter months leads to lower levels of vitamin D and melatonin.” Being low in these substances may undermine your immune system and your ability to fight off infection, he explains. Stay safe by getting a flu shot, he recommends. Next, make sure you don’t ignore these clear symptoms you have the flu.