Second wave

Indoor venues are public enemy No 1, warns Wits prof as second wave hits

The message is clear: sit outside, or don't go to a restaurant at all

09 December 2020 - 21:01
By tanya farber AND Tanya Farber
Second waves of Covid-19 are hitting countries all over the world, pushing up deaths. SA is not being spared and indoor superspreader events are the main culprit, says a Wits professor.
Image: REUTERS/AJENG DINAR ULFIANA Second waves of Covid-19 are hitting countries all over the world, pushing up deaths. SA is not being spared and indoor superspreader events are the main culprit, says a Wits professor.

“It makes no sense to close beaches but keep places of worship open. Walking on the beach without a mask is not the main problem here. People gathering in places with poor ventilation are the problem. We’re talking about shebeens, pubs, clubs, indoor seating at restaurants.”

So says Prof Shabir Madhi, a vaccinologist at Wits University who has been leading clinical trials for Covid-19 vaccines in SA, and who says it is clear that airborne transmission of the virus — and thus ventilation — are critical factors to consider as the second wave hits.

He was speaking on Wednesday afternoon, just hours before health minister Dr Zweli Mkhize confirmed that a second wave of infections had hit SA.

Even at 50% occupancy, you “can still end up with a superspreader event”.

“Good ventilation in any situation is absolutely essential,” said Madhi, “because infected airborne droplets generally stay in the air for at least 10-12 minutes, but in a poorly ventilated space, can even hang around for up to one or two hours.

Speaking on online broadcast channel MyHealth, Madhi was responding to recent allegations that local authorities in KwaZulu-Natal and Nelson Mandela Bay were considering closing beaches.

He says good ventilation can save us as the second wave hits.

Wits University’s professor Shabir Madhi.
Image: Supplied Wits University’s professor Shabir Madhi.

“Unfortunately, we are heading into the second wave. Nelson Mandela Bay is in the midst of a resurgence, while in the Western Cape, in George and along the Garden Route there are clear signs of resurgence,” he added.

He said it had become apparent that airborne transmission is an even more important consideration than hand hygiene.

Airflow plays an important role, he explained, so when you’re outdoors, the droplets get dispersed more quickly and there’s less chance of being infected.

As soon as you’re indoors “every window and door — absolutely everything — have to be open”.

“Even physical distancing won’t help if you’re in a closed space without great ventilation. Even if it is a small number of people and there is physical distancing, it doesn’t help if there is poor ventilation — it is about airborne transmission. Even an air-conditioning system can actually distribute the virus to a different room,” he said.

He added that “droplets from the infected in poorly ventilated venues can stay in the air for up to two hours”.

“Someone just has to inhale those particles or it could be through the eyes or nose or mouth alone — and they will enter your body and infect you,” he said.

The message is clear: if you go to a restaurant, “sit outside or don’t go at all”.

Madhi lamented the fact that young people were still attending gatherings like matric parties and organised “Rage” events. Others were still passing round hookah pipes, with no consideration of the effect this could have on whole communities.

“They will inadvertently take those viruses home to their families,” he cautioned.

He said you could “rest assured” that “any matric Rage parties” would fuel and have already fuelled an uptick in infections.

“People have become complacent and when people start gathering — especially in poorly ventilated spaces — you get a resurgence. We have seen that in parts of the country and if it carries on, we will see a much more generalised resurgence across the country by February,” he said.


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