Patients are crammed into every corner of the hospital's emergency room ward. They lie on beds and gurneys, or sit slumped in wheelchairs. Many suck on oxygen, but nobody talks. Some die while waiting for a bed.

On the worst nights in Johannesburg, currently in the grips of a terrible wave of infections, medics at one hospital must turn away ambulances carrying Covid-19 patients. It may be a diversion order more common to mass casualty events, but 16 months into the pandemic here, Covid-19 is a mass casualty event.

"It's devastating, it's soul destroying. We are trained to save lives, but you revert to that wartime mentality. You revert to becoming numbed, you revert to becoming blunted," said a senior doctor at a major public hospital in South Africa's largest city.

"Patients are being brought in in cars with desperately ill patients who have been turned away from other hospitals with no beds."