Have you ever wondered why thewinteris the time chosen by the flu virus to attack our respiratory system? According to a study by virologist Peter Palese, from the Mount Sinai School of Medicine (New York), this preference is due to the fact thatlow temperaturesand thedecrease in humiditystrengthen the virus.
Traditionally, some specialists blamed the increase in flu processes on the tendency of people to spend more time in contact with others inclosed placesduring the cold season. However, there was no scientific data to confirm this suspicion.
Palese has broken this myth by demonstrating, through a series of experiments with guinea pigs infected with the human influenza virus, that this disease is transmitted to at least 8 out of 10 animals when the relative humidity is between 20 and 35 percent, while when the humidity exceeds 80 percent, the virus is not transmitted. In addition,higher rates of contagion, according to experiments, occur at a temperature of5ºC. In that case, just talking, coughing or sneezing is enough to send the virus into the air so that other individuals can breathe it in. However, when the mercury reaches 30ºC, the transmission of the virus is non-existent.
One possible explanation, says the researcher, is that the virus could be more stable at low temperatures and with little water vapor in the atmosphere. Another possibility that is being considered is thatphysical barriers that protect usfrom microorganisms, such as the mucous membrane of the nose,lose their effectivenessin these weather conditions. Future experiments with humans will help clear up these doubts.
