COVID-19 control in low-income settings and displaced populations: what can realistically be done?

While modelling predictions1 suggest that uncontrolled or even partially mitigated COVID-19 epidemics in high-income countries could lead to substantial excess mortality, the virus’ impact on people living in low-income settings or affected by humanitarian crises could potentially be even more severe. Three mechanisms could determine this: (i) higher transmissibility due to larger household sizes2, intense social mixing3 between the young and elderly4, overcrowding in urban slums and displaced people’s camps, inadequate water and sanitation, and specific cultural and faith practices such as mass prayer gatherings, large weddings and funerals during which super-spreading events might propagate transmission disproportionately5; (ii) higher infection-to-case ratios and progression to severe disease due to the virus’ interaction with highly prevalent co-morbidities, including non-communicable diseases (NCDs; prevalence of hypertension and diabetes is often higher in low- than high-income settings, with a far lower treatment coverage6), undernutrition, tuberculosis7 and HIV; and (iii) higher case-fatality due to a dire lack of intensive care capacity, especially outside large cities. Moreover, extreme pressure on curative health services could result in indirect impacts resulting from disrupted care for health problems other than COVID-19.8 While these risk factors could be counterbalanced by younger age distributions and hot temperatures, on balance we believe that, given current evidence and plausible reasoning, drastic action is required immediately to protect the world’s most fragile populations from this unfolding threat.