The researchers from China and Europe found in an international collaborative study that humidity and temperature in the environment affect coronavirus symptoms.
Researchers compared the outcomes of more than 40,000 COVID-19 patients during the pandemic that suggested the symptoms of coronavirus are more severe in cold weather than warm ones. Moreover, dry indoor air plays a significant role in the rapid spread of the virus.
Several viruses have shown seasonal incidence with being more common during the cold winters, but the scientists were not aware of the effect of weather on coronavirus. The results from prior studies were inconsistent that believed the transmission of coronavirus decreases in high temperature and humidity. In the United States, scientists found that sunlight and humidity can kill coronavirus and therefore decrease the spread.
Researchers analyzed the data from about 7,000 coronavirus patients in the hospitals of the United Kingdom, Croatia, China, Spain, Germany, Italy, Poland, and Finland. Information from the data was mapped on local temperatures and humidity that found a decrease in the severity of COVID-19 and transmission of the virus from winter to summer.
A corresponding decrease in the mortality rate was also observed, with about 15% of drop-in deaths as a rise in temperature was recorded. On the contrary, the symptoms of coronavirus were severe in winter during the first wave of COVID-19 in China. Moreover, the COVID-19 Symptom study app also showed a decrease in the reporting of symptoms in the United Kingdom as the temperature increased.
Additionally, the researchers pointed out that the indoor system of heating in winters dries out the protective mucus barriers in the airways and nose, contributing to the spread of disease. Dr. Gordon Lauc, the lead author of the study, said,
“The next winter in Europe when more severe ‘winter’ COVID-19 is expected to return – something we are currently observing in the southern hemisphere.”
Professor of Genetic Epidemiology, Tim Spector at the King’s College London gave his statement,
“By understanding many factors that contribute to the severity and spread of the disease, we can implement effective measures to control it over the coming months.”
The study has not been published for peer-review yet, and experts are looking for further evidence to gain in-depth knowledge of coronavirus.