Comparative Analysis of COVID-19 Prevalence in Coastal Versus Inland Populations of North Carolina

Statement of Significance This study aimed to assess geographic trends in COVID-19 cases and deaths across North Carolina (NC). Our study found that population-adjusted COVID-19 cases and deaths were lower in the coastal region of NC during the study period, independent of demographic composition and population-density within the region. This represents an interesting finding regarding COVID-19 transmission that deserves further investigation. One possible explanation for this finding is differing environmental conditions between the inland and coastal region.   Background: Existing literature has explored the geographic and spatial variations in COVID-19 prevalence. Some studies suggest that the transmission and total prevalence of COVID-19 is diminished in areas with low levels of air pollution, high humidity, and more sunlight. The coastal regions of NC are more likely to have these environmental characteristics than the inland regions. Given these trends, we analyzed and compared population-adjusted COVID-19 case and death counts in the coastal and inland regions of NC. Methods: Time series data displaying the prevalence of population adjusted COVID-19 case and death counts from 15 March 2020 to 15 August 2020 were plotted for a variety of North Carolina regional and population density classifications. A local regression analysis was computed to further assess the observed relationships. Basic demographic characteristics were also compared for the coastal versus inland region. Results: There were fewer population-adjusted COVID-19 cases and deaths in the coastal region (889 cases/100,000; 12.5 deaths/100,000) than in the inland region (1426 cases/100,000; 23.5 deaths/100,000) at the endpoint of this study. This trend is observed even when controlling for population density, and in the absence of significant demographic differences between the two regions. Conclusions: The prevalence of population-adjusted COVID-19 cases and deaths was lower in coastal versus inland NC during this study period. Given that the NC coastal region is associated with lower pollution, higher humidity, and more exposure to sunlight, our findings suggest that more research should be done to explore the correlation between environmental variables and the spread of COVID-19.