Summer WON’T curb the spread of the coronavirus: Study debunks claims that warmer weather will halt the pandemic
- Researchers examined the rate of spread of COVID-19 across 224 Chinese cities
- They compared this with local temperature, humidity and incoming UV radiation
- The team found no significant association between weather and infection rates
Summer will not curb the spread of the coronavirus in the northern hemisphere, a study has found — dashing hopes that warmer weather will halt the pandemic.
The transmission of many infectious diseases — such as influenza and SARS — are known to be impeded by increases in the ambient temperature.
Previous studies from both Beihang and Tsinghua Universities had concluded that the transmission rate of COVID-19 in China fell in as the temperature grew warmer.
However, the latest work comparing transmission rates with the weather by researchers from Fudan University has concluded there was no such relationship.
The findings come as both New Zealand and Australia report falling infection rates as they declare successes in breaking the coronavirus’ chain of the transmission.
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Summer will not curb the spread of the coronavirus in the northern hemisphere, a study has found — dashing hopes that warmer weather will halt the pandemic (stock image)
WHY WAS IT HOPED SUMMER WOULD SLOW THE SPREAD?
The transmission of many infectious diseases — for example, influenza and SARS — are thought to be impeded during the summer.
Scientists believe that warmer seasons slow the spread of viruses for a number of reasons.
- More sunlight allows the body to produce more vitamin D from cholesterol, resulting in better immune responses.
- The fact that schools are out, meaning that children are not clustered together to allow easier viral transmission.
- Increased UV radiation, which has been suggested can slow the spread of respiratory diseases.
The investigation was undertaken by public health expert Weibing Wang and colleagues from Fudan University in Shanghai, China.
‘Our analysis suggested that ambient temperature has no significant impact on the transmission ability of SARS-CoV-2,’ the researchers said.
‘It is premature to count on warmer weather to control COVID-19, and relying on seasonality to curb this pandemic can be a dangerous line of thought.’
‘Changing seasons may help but are unlikely to stop transmission,’ the team added.
‘Urgent policies or interventions — such as community travel bans and school closures — are needed to help slow transmission.’
In their study, Dr Wang and colleagues analysed the spread of coronavirus in 224 Chinese cities — including 17 in Hubei province, where the outbreak began — using data from the National Health Commission and the Provincial Health Commissions.
They then compared this information with daily weather data — including measurements of the mean temperature, relative humidity and incoming ultraviolet (UV) radiation — over the period between January and early March 2020.
The team found that there was no significant association between either the temperature or the levels of UV exposure from sunlight and the total infection rate, both in cities inside and outside of Hubei province.
COVID-19 would not be the first infectious disease to defy expectations and remain unaffected by the arrival of warmer weather, the researchers note.
Total case numbers in the MERS epidemic in the Arabian Peninsula were known to continue developing when temperatures reached as high as 113°F (45°C).
Other recently emerged diseases transmitted from animals into humans — including Ebola and some strains of influenza — have also occurred in unpredictable patterns.
‘Our analysis suggested that ambient temperature has no significant impact on the transmission ability of SARS-CoV-2,’ the researchers said. ‘It is premature to count on warmer weather to control COVID-19, and relying on seasonality to curb this pandemic can be a dangerous line of thought’
‘Even though the transmission of SARS, which began in November, 2002, and ended in July, 2003, suggests it might be seasonal,’ the researchers concluded.
‘It also might have been controlled by effective case finding, contact tracing and quarantine.’
The full findings of the study were published in the European Respiratory Journal.
NEW ZEALAND AND AUSTRALIA SEE COVID-19 TIDE TURNING
New Zealand’s prime minister Jacinda Ardern says her country is winning the battle against coronavirus after just 29 new cases were added to the tally today.
Australia and New Zealand have both seen falling infection rates after closing their borders by March 20 – something Britain has still not done.
Ardern hailed New Zealanders for mounting a ‘wall of defence’ which is ‘breaking the chain of transmission’ after the country moved quickly to impose a lockdown.
This graph shows the daily number of coronavirus cases recorded each day in New Zealand (in yellow), according to figures from the government health ministry. The red line shows the falling rate of growth in virus cases
The PM said the country was already ‘turning a corner’ just six weeks after the epidemic reached New Zealand, which has only 992 confirmed cases and one death so far.
Lockdown measures could be softened in just over a week, Ardern said, opening the door for some people to return to work if their employers can ensure social distancing.
The figure of 29 confirmed or probable infections in the last 24 hours marks a fourth straight day of decline, in the latest sign of a flattening curve.
New Zealand only confirmed its first case on February 26, but had shut its borders by March 19 and started imposing a full-scale lockdown on March 26.
Australia has also squashed the curve, with both countries carrying out more widespread tests than Britain or the United States.
This graph shows the flattening curve in Australia, where drastic measures were imposed at an earlier stage than in much of Europe