Currently, there are no confirmed cases of 2019-nCoV in Africa, but multiple people suspected of infection, based on their travel history and symptoms, have been identified at the borders of a growing number of African countries. If the cases start to occur within the borders of these countries—and without obvious links to known sources of infection—properly diagnosing those infected will be extraordinarily difficult.

If the 2019-nCoV epidemic spreads around the world, rich countries may decide to test incoming travelers who display compatible symptoms. In poor communities, identifying those carrying the virus will be even harder. To test routinely for the large number of patients expected from the most pessimistic predictions about the 2019-nCoV epidemic, a herculean burden will need to be placed on national laboratories. Most important, a large-scale testing policy will require health-care workers to treat patients, collect all these individual samples, and ship them to central laboratories because no bedside rapid diagnostic tests are currently available for 2019-nCoV virus. In the face of competing needs from diseases with much higher mortality rates, how realistic is such a proposal?

The 2019-nCoV acute respiratory disease may manifest profoundly differently in poor regions of the world. Currently, older patients and those with chronic ailments seem to get more severely ill from coronavirus and are at higher risk of death. In the developing world, 2019-nCoV could conceivably yield more severe disease and higher mortality rates because of underlying malnutrition and other concurrent infections (as we see with tuberculosis and influenza).