Cold snap could result in infections ‘snowballing’

A SHORT spell of cold weather could result in an increase in coronavirus cases, scientists have warned.

Cooler temperatures mean weather droplets containing virus particles remain on surfaces for longer as they take more time to evaporate.

Joshua Moon, a specialist in global health security at the University of Sussex, said this could increase the rate of transmission of Covid-19 between people who come into contact with unclean surfaces.

He stressed that the speed of infection depended much on human behaviour, with people more likely to stay inside and observe social distancing guidelines when it is cold.

However, Dr Moon, who is a research fellow at the institution’s Science Policy Research Unit, noted that even a short period of cooler weather may cause a rise in cases.

He said: “There is a lot of uncertainty about the different weather patterns and how it will affect the virus from a viral droplet perspective.

“On the one hand, cooler weather could be quite damaging because it means there is going to be more droplets around.

“Even a small increase in cases can multiply with issues like asymptomatic and pre-symptomatic transmissions – people who do not have symptoms who in some cases transmit the virus. Although, that is not as common as people with symptoms spreading it.

“So, even a slight uptick in cold weather resulting in possibly more people getting infected could end up snowballing into a larger number of cases.”

Researchers from Beihang and Tsinghua universities in China, who have studied how the coronavirus has spread in 100 Chinese cities, found that “high temperature and high relative humidity significantly reduce the transmission of Covid-19”.

It is hoped summer may bring some respite, but uncertainty still remains over whether Covid-19 will behave like flus and colds, which peak in winter.