A new research has substantiated that low temperatures and relative dampness promote influenza.
Influenza, commonly known as flu, has long been considered a seasonal virus.
Factors responsible for the spread of the infection include indoor crowding during cold weather, seasonal fluctuations in host immune responses, relative humidity, temperature, and UV radiation, but none of these hypotheses had previously been tested directly.
Led by Dr. Peter Palese, from the Mount Sinai School of Medicine, the research team therefore examined the effects of temperature and relative humidity on infected and naive guinea pigs.
After the test, they found that low relative humidities of 20 percent-30 percent induced the rapid spread of the virus, with the opposite effect at 80 percent or above.
Also, results showed that the virus spread more easily at 5 °C than at 20 °C, with no transmission at 30 °C.
The result of the study therefore implicates that low relative humidities produced by indoor heating and winter temperatures favour the spread of influenza.