Per capita COVID-19 disease burden and healthcare system demand may be highest in rural areas in the US, according to a modelling study. These findings underscore the importance of ensuring that access to medical care and public-health resources are available to communities outside of urban areas.
Identifying regions of the US in which the number of COVID-19 cases is highest is crucial for the distribution of emergency medical services and public-health resources during the pandemic. Ian Miller and colleagues at the department of ecology and evolutionary biology and the Woodrow Wilson School of Public Affairs at Princeton University used age-specific mortality patterns along with demographic data to map the cumulative case burden of COVID-19 and the subsequent burden on healthcare resources across the US.
The authors developed a modified susceptible-exposed-infected-recovered epidemiological model and performed the analysis on 3,142 counties and county equivalents under a scenario in which 20% of the population of each county acquires infection.
They identified counties that are likely to be consistently more heavily affected than the rest of the country across a range of assumptions about transmission patterns, such as basic disease reproductive rate, contact patterns and efficacy of quarantine.
The authors found several regions in need of additional support, including much of the western part of the US, the northern Midwest, Florida and northern New England. Since age is associated with disease severity, the areas with the highest per capita burden were those with the highest percentages of people over the age of 60 years.
Future research is needed to consider how other factors linked with an increase in disease risk – such as pre-existing health conditions, societal factors or decreased access to medical care – might exacerbate disease burden in certain regions. The authors urge public-health officials to carefully consider patterns of relative burdens rather than projections for individual counties when planning emergency responses.
Abstract
As of 24 April 2020, the SARS-CoV-2 epidemic has resulted in over 830,000 confirmed infections in the United States1. The incidence of COVID-19, the disease associated with this new coronavirus, continues to rise. The epidemic threatens to overwhelm healthcare systems, and identifying those regions where the disease burden is likely to be high relative to the rest of the country is critical for enabling prudent and effective distribution of emergency medical care and public health resources. Globally, the risk of severe outcomes associated with COVID-19 has consistently been observed to increase with age2,3. We used age-specific mortality patterns in tandem with demographic data to map projections of the cumulative case burden of COVID-19 and the subsequent burden on healthcare resources. The analysis was performed at the county level across the United States, assuming a scenario in which 20% of the population of each county acquires infection. We identified counties that will probably be consistently, heavily affected relative to the rest of the country across a range of assumptions about transmission patterns, such as the basic reproductive rate, contact patterns and the efficacy of quarantine. We observed a general pattern that per capita disease burden and relative healthcare system demand may be highest away from major population centers. These findings highlight the importance of ensuring equitable and adequate allocation of medical care and public health resources to communities outside of major urban areas.
Authors
Ian F Miller, Alexander D Becker, Bryan T Grenfell, C Jessica E Metcalf
[link url="https://www.nature.com/articles/s41591-020-0952-y"]Nature abstract[/link]