We all know that flu season hits hardest in the winter, but have you ever wondered why? The New York Times reports that the flu virus ‘is more stable and stays in the air longer when air is cold and dry, the exact conditions for much of the flu season.’
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A flu researcher from the microbiology department at Mount Sinai School of Medicine in New York adds, ‘Influenza virus is more likely to be transmitted during winter on the way to the subway than in a warm room.’
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Interestingly, some historians have suggested that the name influenza comes from the Italian influenza di freddo, which means ‘influence of the cold.’
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To test why the flu virus is so prevalent in the winter months, the researchers used guinea pigs and altered both the temperature and humidity in their living quarters. Transmission excelled at 41 degrees, and declined steadily as the temperature got warmer. By 86 degrees, the virus wasn't passed around at all.
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The findings confirmed that ‘the virus was transmitted best at a low humidity, 20 percent, and not transmitted at all when the humidity reached 80 percent.’ Flu viruses are airborne (unlike colds, which spread more through direct contact with infected surfaces). The virus is more stable in cold air, and low humidity helps the virus particles stay in the air. Humid air, on the other hand, causes the virus particles to pick up more water and then fall to the ground — where we can't breathe them.
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Based on this reasearch, experts recommend setting room temperatures near 69 degrees Farenheit and keeping rooms at around 50% humidity.
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Monitoring your home's temperature and humidity is an important part of keeping your family healthy in the winter months. A humidity gauge can help you keep humidity at the recommended levels. And using a humidifier not only eases the adverse effects of dry witner air, but can even help protect you and your family against winter's dreaded flu.