'Warmer weather won't affect infections,' say experts

While the country's peak of Covid-19 infections is expected to gradually plateau after September, the warmer weather will not be the cause as there is still no evidence change of seasons impacts the survival of the virus. A team of expert modellers assisting the department of health predicted the country's peak would be in July, August and September, Minister of Health Zweli Mkhize said recently. "We think this is the major thrust that we are going through – July and August. After that, we should be getting the numbers to slow down a little bit," he said. While winter saw...
While the country's peak of Covid-19 infections is expected to gradually plateau after September, the warmer weather will not be the cause as there is still no evidence change of seasons impacts the survival of the virus.

A team of expert modellers assisting the department of health predicted the country's peak would be in July, August and September, Minister of Health Zweli Mkhize said recently.

"We think this is the major thrust that we are going through – July and August. After that, we should be getting the numbers to slow down a little bit," he said.

While winter saw a spike in Covid-19 infections, this was not because the virus survived better in the cold, said experts. It was most likely because people spent more time indoors with less ventilation, increasing the risk of infection, said head of University of Cape Town's School of Public Health and Family Medicine Professor Landon Myer.

"Many respiratory illnesses caused by viruses are more common in the winter months, which is thought to be related to the biology of the pathogens and/or the changing patterns of human interaction – as people often spend more time indoors in the winter, often with less ventilation, thus facilitating transmission of respiratory pathogens," he said.

Warmer weather often came with better ventilation which potentially had a possible indirect effect on limiting the spread of the virus, said Wits School of Governance head Professor Alex van den Heever.

"What you see in the US is huge surges in the epidemic in certain states where the weather is hotter than South Africa, like Florida, Texas and California. I don't think there is any real evidence that seasonality in weather directly impacts on the virus itself. "It may, however, have indirect influence," he said.

The projected slow infectious rate expected after September could be due to the known natural progression of the epidemic, meaning the decline could partly be because of the decreasing number of people who can be newly infected, Myer said.

"The epidemic first peaked in the Western Cape around May and already we are starting to see decreases in the epidemic there. "In Gauteng and the eastern parts of the country, this peak may be coming in August and September and then, perhaps, we will be on the decline by October," he said.

rorisangk@citizen.co.za

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