A new modeling study evaluating unfolding COVID-19 epidemics among different income countries reports that, in lower income countries, even if risk is reduced because populations are younger, this benefit is largely negated by limited health system capacity and closer inter-generational contact. In these places, efforts to mitigate the virus will need to be maintained or triggered more frequently, say the authors.
The results offer insight into how differences in demography, social structure and healthcare availability and quality combine to influence the impact of virus mitigation measures. The COVID-19 epidemic places intense pressure on national health systems. To date, this has sometimes outstripped availability of resources even in relatively highly resourced settings.
Many lower income, resource-poor countries have acted while transmission remains at low levels, which is likely to have substantially slowed the spread of the virus, but questions remain about future virus spread. To better understand the factors that could result in a differential impact of the COVID-19 pandemic in low- and middle-income countries (LMICs), Patrick Walker and colleagues calibrated a global model with country-specific data on demography, contact patterns, disease severity, and healthcare capacity.
In lower income countries, despite risk being reduced by a younger population, they say, overall risk is still higher due to a limited health system capacity coupled with closer inter-generational contact. In these locations, mitigation strategies that slow but do not interrupt transmission will still lead to COVID-19 epidemics rapidly overwhelming health systems. A short-term priority in such locations should be to increase the availability of oxygen support to mitigate the health impact. In the longer-term, ensuring equitable provision of pharmaceutical interventions, once they are developed, should be a global focus.
"While our results illustrate the challenges that many countries will face in attempting to mitigate the impact of local COVID-19 epidemics, it is important to bear in mind that even moderate levels of changes in behavior can avert many infections and hence save millions of lives."
Walker, P.G.T., et al. (2020) The impact of COVID-19 and strategies for mitigation and suppression in low- and middle-income countries. Science. doi.org/10.1126/science.abc0035.