Viruses spread faster in densely populated urban areas and, in a nation defined by inequality, the poor are most at risk. Gauteng, South Africa's smallest yet most populous province, is the epicentre in the country's Covid-19 battle and Premier David Makhura is ready to take 'extraordinary measures' to limit the virus's impact.
"Wars and refugee camps and urban overcrowding give the worst flu strains a huge evolutionary advantage," wrote Malcolm Gladwell in his 1997 feature on the Spanish flu.
South Africa isn't at war and doesn't have refugee camps, but the risk of Covid-19 spreading to densely populated urban areas and informal settlements has been a key factor in the government's decision to impose a nationwide lockdown.
Cabinet members have stressed the point during briefings throughout the week: the majority of Covid-19 cases have come from people who have travelled abroad, but if local transmissions start to spread in overpopulated urban areas, informal settlements, on the taxis and trains, contacts will be difficult to trace and the rate of infections could overwhelm the health system.
Nowhere is this more relevant than in Gauteng.
As of Wednesday morning, Gauteng had 366 confirmed cases of Covid-19 out of the country's total of...