Good Ventilation is a Key Factor in Reducing New Covid-19 infections

By the Daily Maverick

The looting and unrest in KwaZulu-Natal and Gauteng in mid-July 2021 was, from a Covid-19 perspective, a damp squib. There is no clear evidence in the numbers to support the dire predictions at the time that the gatherings of thousands of people to loot and burn property would be a super-spreader event.

True, the Institute for Water and Wastewater Technology found an increase in infected effluent at the eThekwini Central Wastewater Treatment plant two weeks later. But other simultaneous factors make it difficult to draw simplistic conclusions: the whole country had just moved from level 4 to level 3 lockdown and infection rates were still rising everywhere. In fact, the graphs show that the trajectory in infections in KwaZulu-Natal during that period mirrors that of the Western Cape, where there was no looting.

To analyse this in depth would take considerably more than a quick glance at the graphs. It is very likely that there was at least some increase in transmission from crowd behaviour. However, we believe there was a fundamental, often-overlooked reason why this was not a super-spreader catastrophe.

Unlike the disastrous Matric Rage events in late 2020, the unrest in KwaZulu-Natal and Gauteng for the most part, took place in the open air, not within confined or poorly ventilated spaces. It underlines the importance of good ventilation – a critical public health factor that has not been prioritised or emphasised enough in all the public health messaging advice dispensed by the government and other leading institutions – to effectively limit Covid-19 transmission.

continue reading…

SARACCA