Prime minister Narendra Modi warned that if India did not get the next 21 days right it would risk wiping out the gains of 21 years. In South Africa, Cyril Ramaphosa ordered one of the world’s strictest lockdowns before the country had registered even a single coronavirus death. The three-week shutdown was necessary, the president said, to save hundreds of thousands of lives. All across the developing world – with some exceptions, including Brazil – leaders are closing their economies to stop the pandemic. But in countries with high death rates from other illnesses and with brutal levels of poverty, could the cure actually be worse than the disease?

In an era of groupthink, in which not to impose a lockdown risks accusations of mass killing, it is at least worth posing the question. Even if leaders such as Mr Modi or Mr Ramaphosa hold private doubts, their instincts for political survival might force them onward. No one is likely to lose support for being too tough on coronavirus. To state the obvious, it is harder to impose a lockdown in a poor country than in a rich one. In huge cities such as Lagos, Mumbai or Manilla, instructing people to stay at home is to confine millions to cramped housing. In the slums where up to half the population may live, people could be crammed six or eight to a room, with no easy access to water, or even soap.

Arundhati Roy, the Indian author and political activist, has called the lockdown not an act of social distancing but rather one of “social compression”. It is hard enough to keep wealthy economies ticking over in a lockdown. In poor countries, huge informal economies are a double-edged sword. They may act as shock absorbers. Some people might be able to leave the city and scrape a living on family plots of land. In other ways, informal economies make things more difficult.

People who eke out an income by hawking roadside goods, fixing pots and pans, shining shoes or braiding tourists’ hair have little way of surviving if they are forced indoors. Within hours of India ‘s lockdown order, there were pitiable scenes of migrant workers trudging home by foot, in some cases hundreds of miles. In South Africa, too, signs of social stress are everywhere. Police have used rubber bullets and tear gas to enforce social distancing in the crowded townships, where the black majority still lives a quarter of a century after the end of apartheid.

Then there are the silent bombs, the invisible consequences of fighting one disease to the possible neglect of others·. while we obsessively count the coronavirus death toll, only a dedicated few worries about possible knock-on effects in a country such as the Democratic Republic of Congo where measles killed 6,200 and malaria 17,000 last year. If economies crash, silent killers such as diarrhoea,  malnutrition and infant mortality may sweep through populations.