Coronavirus ‘highly sensitive’ to high temperatures, but don’t bank on summer killing it off, studies say
- Pathogen appears to spread fastest at 8.72 degrees Celsius, so countries in colder climes should ‘adopt the strictest control measures’, according to researchers from Sun Yat-sen University in Guangdong province
- But head of WHO’s health emergencies programme says it is ‘a false hope’ to think Covid-19 will just disappear like the flu
The study, by a team from Sun Yat-sen University in Guangzhou, the capital of south China’s Guangdong province, sought to determine how the spread of the new coronavirus might be affected by changes in season and temperature.
Published last month, though yet to be peer-reviewed, the report suggested heat had a significant role to play in how the virus behaves.
“Temperature could significantly change Covid-19 transmission,” it said. “And there might be a best temperature for viral transmission.”
The “virus is highly sensitive to high temperature”, which could prevent it from spreading in warmer countries, while the opposite appeared to be true in colder climes, the study said.
As a result, it suggested that “countries and regions with a lower temperature adopt the strictest control measures”.
Many national governments and health authorities are banking on the coronavirus losing some of its potency as the weather warms up, as is generally the case with similar viruses that cause the common cold and influenza.
“Weather alone, [such as an] increase of temperature and humidity as the spring and summer months arrive in the Northern Hemisphere, will not necessarily lead to declines in case counts without the implementation of extensive public health interventions,” said the study, which was published in February and is also awaiting scientific review.
The Guangzhou team based their study on every novel coronavirus case confirmed around the world between January 20 and February 4, including in more than 400 Chinese cities and regions. These were then modelled against official meteorological data for January from across China and the capital cities of each country affected.
The analysis indicated that case numbers rose in line with average temperatures up to a peak of 8.72 degrees Celsius and then declined.
“Temperature … has an impact on people’s living environments … [and] could play a significant role in public health in terms of epidemic development and control,” the study said.
Other experts, like Hassan Zaraket, an assistant director at the Centre for Infectious Diseases Research at the American University of Beirut, said it was possible that warmer, more humid weather would make the coronavirus less stable and thus less transmissible, as was the case with other viral pathogens.
“We are still learning about this virus, but based on what we know of other coronaviruses we can be hopeful,” he said.
“As temperatures are warming up, the stability of the virus could decrease … if the weather helps us reduce transmissibility and environmental stability of the virus, then maybe we can break the chain of transmission.”
However, even if this were the case, the benefit would be greatest in areas that had yet to see widespread community transmission of Covid-19, he said.
“We have to assume the virus will continue to have the capacity to spread,” he said.
“It’s a false hope to say, yes, it will disappear like the flu … we can’t make that assumption. And there is no evidence.”
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