Lower daily temperatures can lead to higher transmission of Covid-19, says a new research published in PLOS ONE.
Researchers at the University of Louisville’s Christina Lee Brown Environment Institute, the Johns Hopkins University School of Medicine, the US Department of Defense Joint Artificial Intelligence Centre and others tried to better understand the impact of atmospheric temperature on the transmission of the SARS-CoV-2 virus.
The researchers compared daily low-temperature data and recorded cases of Covid-19 in 50 countries in the northern hemisphere between January 22 and April 6, 2020.
According to the data analysed, as temperatures rose, the rate of new cases of Covid-19 decreased.
Between 30 and 100 degrees Fahrenheit, a 1-degree Fahrenheit increase in daily low temperature was related to a 1 per cent decrease in the rate of increase in cases, and a 1-degree decrease in temperature was related to an increase in that rate by 3.7 per cent, the data analysis showed, said an official release published in Eurekalert!
Researchers analysed early data of the pandemic in order to obtain results without significant influence by lockdowns, masking or other social efforts to contain the virus.
“Although Covid-19 is an infectious disease that will have non-temperature-dependent transmission, our research indicates that it also may have a seasonal component,” said Aruni Bhatnagar, co-author and director of the Brown Environment Institute.
“Of course, the effect of temperature on the rate of transmission is altered by social interventions like distancing, as well as time spent indoors and other factors. A combination of these factors ultimately determines the spread of Covid-19,” Bhatnagar said.
Researchers further found that Covid-19 transmission is slower in summer months, similar to other seasonal respiratory viruses. The data also indicated that the correlation between temperature and transmission was much higher than the association between temperature and recovery or death from Covid-19.
“This understanding of the SARS-CoV-2 temperature sensitivity has important implications for anticipating the course of the pandemic,” said Adam Kaplin of Johns Hopkins, first author of the study.
“We do not know how long the currently available vaccines will sustain their benefits, nor what the risks are of new variants developing over time if the northern and southern hemispheres continue to exchange Covid-19, back and forth across the equator, due to their opposing seasons. But it is reasonable to conclude that this research suggests that, like other seasonal viruses, SARS-CoV-2 could prove to be extremely difficult to contain over time unless there is a concerted and collaborative global effort to work to end this pandemic,” Kaplin said.