SARS-CoV-2 transmission potential and rural-urban disease burden disparities across Alabama, Louisiana, and Mississippi, March 2020 - May 2021

Sylvia K Ofori; Chigozie A Ogwara; Seoyon Kwon; Xinyi Hua; Kamryn M Martin; Arshpreet Kaur Mallhi; Felix Twum; Gerardo Chowell; Isaac C-H Fung

doi:10.1016/j.annepidem.2022.04.006

SARS-CoV-2 transmission potential and rural-urban disease burden disparities across Alabama, Louisiana, and Mississippi, March 2020 - May 2021

Ann Epidemiol. 2022 Jul:71:1-8. doi: 10.1016/j.annepidem.2022.04.006. Epub 2022 Apr 25.

Authors

Sylvia K Ofori¹, Chigozie A Ogwara¹, Seoyon Kwon¹, Xinyi Hua¹, Kamryn M Martin², Arshpreet Kaur Mallhi¹, Felix Twum³, Gerardo Chowell⁴, Isaac C-H Fung⁵

Affiliations

¹ Department of Biostatistics, Epidemiology and Environmental Health Sciences, Jiann-Ping Hsu College of Public Health, Georgia Southern University, Statesboro, GA.
² Department of Health Sciences and Kinesiology, Waters College of Health Professions, Statesboro, GA.
³ The Dr. Lynn Cook Hartwig Public Health Program, The University of Southern Mississippi, Hattiesburg, MS.
⁴ Department of Population Health Sciences, School of Public Health, Georgia State University, Atlanta, GA.
⁵ Department of Biostatistics, Epidemiology and Environmental Health Sciences, Jiann-Ping Hsu College of Public Health, Georgia Southern University, Statesboro, GA. Electronic address: cfung@georgiasouthern.edu.

Abstract

Purpose: To quantify and compare SARS-CoV-2 transmission potential across Alabama, Louisiana, and Mississippi and selected counties.

Methods: To determine the time-varying reproduction number R_t of SARS-CoV-2, we applied the R package EpiEstim to the time series of daily incidence of confirmed cases (mid-March 2020 - May 17, 2021) shifted backward by 9 days. Median R_t percentage change when policies changed was determined. Linear regression was performed between log₁₀-transformed cumulative incidence and log₁₀-transformed population size at four time points.

Results: Stay-at-home orders, face mask mandates, and vaccinations were associated with the most significant reductions in SARS-CoV-2 transmission in the three southern states. R_t across the three states decreased significantly by ≥20% following stay-at-home orders. We observed varying degrees of reductions in R_t across states following other policies. Rural Alabama counties experienced higher per capita cumulative cases relative to urban ones as of June 17 and October 17, 2020. Meanwhile, Louisiana and Mississippi saw the disproportionate impact of SARS-CoV-2 in rural counties compared to urban ones throughout the study period.

Conclusion: State and county policies had an impact on local pandemic trajectories. The rural-urban disparities in case burden call for evidence-based approaches in tailoring health promotion interventions and vaccination campaigns to rural residents.

Keywords: COVID-19; Non-pharmaceutical interventions; Reproduction number; SARS-CoV-2; Vaccine.

MeSH terms

Alabama / epidemiology
COVID-19* / epidemiology
Cost of Illness
Humans
Louisiana / epidemiology
Mississippi / epidemiology
SARS-CoV-2*
United States