A warm and humid weather is linked to slower spread of the novel coronavirus, according to a study. The question of whether heat and summer can help stem the flow of the virus has been one that split the medical community

A warm and humid weather is linked to slower spread of the novel coronavirus, according to a study. The question of whether heat and summer can help stem the flow of the virus has been one that split the medical community. While many claimed that there is no adequate proof to back up the claims, now, scientists from the Massachusetts Institute of Technology (MIT) in the US assessed data on the number of COVID-19 infections in different parts of the world and compared it with two parameters of weather from all the regions—temperature and humidity.

“Based on the current data on the spread of 2019-nCoV, we hypothesize that the lower number of cases in tropical countries might be due to warm-humid conditions, under which the spread of the virus might be slower as has been observed for other viruses,” the study claimed, even while noting that the numbers cannot be taken as an absolute.

The scientists cautioned that there are several unknowns in the data currently used to arrive at the conclusion. “Our conclusions are based on currently available data with several unknowns including how the virus is mutating and evolving, case fertility ratio, reproductive numbers and direct versus indirect transmissions,” they said. The researchers also emphasised that the results “in no way suggest that 2019-nCoV would not spread in warm humid regions.”

The finding show that 90 per cent of the novel coronavirus, SARS-CoV-2, transmissions until March 22, 2020 have occurred in regions with temperature between 3 and 17 degrees Celsius. They added that these regions also had between 4 to 9 gram per cubic metre (g/m3) of absolute humidity, a measure of the amount of water vapour per cubic metre of atmosphere. “The higher number of tests and global connectivity of the northern-cooler countries may explain the difference in number of confirmed 2019-nCoV cases between cooler and warmer-humid regions. Nonetheless, several countries between 30N and 30S such as Australia, UAE, Qatar, Singapore, Bahrain, Qatar and Taiwan have performed extensive testing per capita and the number of positive 2019-nCoV cases per capita are lower in these countries compared to several European countries and the US. Therefore, even though currently available data is skewed by minimal testing per capita in many tropical countries, it is possible that weather plays a role in the spread of 2019-nCoV which warrants an investigation,” according to the study conducted by Qasim Bukhari and Yusuf Jameel.