Winters are here and with it comes the thought of how the pandemic might take a turn. Since most respiratory diseases including cold and flu spread quickly in winters, some experts have indicated that COVID-19 cases may also increase with a drop in temperature and humidity. Several studies have also found that SARS-CoV-2, the causative agent of COVID-19, may survive longer and hence will be able to spread more in colder climates. However, scientists still don’t have any conclusions on this.
Some evidence:
A study conducted by Harvard University early this year suggested that there was no link between changing temperature and COVID-19 transmission. The WHO had said that the infection can spread at any temperature. A study done in China indicated that SARS-CoV-2 may spread quickly in summers when the temperature is around 19 degrees Celsius and the relative humidity is at about 75%.
A systematic review published in the journal PLOS One indicated that warm and wet climates are not conducive to the spread of COVID-19 and that the virus would spread better in cold and drier climates. But the authors suggested that temperature and humidity are not the only variables that determine the transmission of the disease.
A study conducted in India also showed an increase in cases of COVID-19 in areas at cold temperatures. Several other studies have also supported the association between cold temperature and the spread of the coronavirus disease.
As per the study, few factors drive the spread of a viral infection which
mainly include environmental factors such as temperature and humidity and host factors.
The researchers suggested that at lower temperatures, enveloped viruses like COVID-19 stay stable for a long because of the improved stability in their lipid envelope. Additionally, less humidity leads to quick evaporation of respiratory droplets which then stay in the air for longer.
But no matter what the temperature is, it is best to keep taking all the precautions including social distancing, wearing face masks, and washing hands. Stay safe and healthy.
