Flu and Cold

The flu, also called influenza, is a viral respiratory illness. A virus is a microscopic infectious agent that invades the cells of your body and makes you sick. The flu is often confused with another virus, the common cold, because of the similarity in symptoms, which can include a cough, sore throat, and stuffy nose. However, flu symptoms also include fever, cold sweats, aches throughout the body, headache, exhaustion, and even some gastro-intestinal symptoms, such as vomiting and diarrhea.

Part of flu potency is from the virus changing so quickly that the body is rarely prepared for the next season’s strain. “The antibodies we have built up no longer recognize the virus, so we lose our immunity.

During the last five years researchers have come up with a way to stem the tide of infection and it revolves around the ways that sneezes linger in the air. Cold air can carry less water vapor before it reaches the dew point and falls as rain. While the weather outside may seem wetter, the air itself is drier as it loses the moisture. A stream of new research has shown that these dry conditions seem to offer the perfect environment for the flu virus to flourish.

Lab experiments have looked at the way flu spreads among groups of guinea pigs. In moister air, the epidemic struggles to build momentum, whereas in drier conditions it spreads quickly. Comparing 30 years’ worth of climate records with health records, Jeffrey Shaman at Columbia University and colleagues found that flu epidemics almost always followed a drop in air humidity.

When we sneeze we expel a mist of particles from our nose and mouths. In moist air, these particles may remain relatively large, and drop to the floor, but in dry air, they break up into smaller pieces, eventually becoming so small that they can stay aloft for many hours. The result is that in winter, you are breathing a cocktail of dead cells, mucus, and viruses from almost anyone who has sneezed in the area.