Transmission dynamics, heterogeneity, and controllability of SARS-CoV-2 in the rural area

Abstract BackgroundsFew studies examine the transmission dynamics and heterogeneity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in rural areas and clarify rural–urban differences. Moreover, the effectiveness of non-pharmaceutical interventions (NPIs) relative to that of vaccination in rural areas is uncertain.MethodsWe addressed this knowledge gap using an improved statistical stochastic method based on the Galton–Watson branching process considering both symptomatic and asymptomatic cases. Data were collected from the epidemiological records of 1136 SARS-2-CoV infections after the rural outbreak in Hebei, China, between 2 January and 20 February 2021.ResultsThe estimated average reproductive number R and dispersion parameter k (k < 1 indicating strong heterogeneity) in the rural area were 0.55 (95% confidence interval [CI]: 0.45–0.68) and 0.14 (95% CI: 0.10–0.20), respectively. Although age group and contact-type distributions significantly differed between urban and rural areas, the \(R\) and \(k\) did not. Further, simulation results based on pre-control parameters (R = 0.81, k = 0.27) showed that in the vaccination scenario (80% efficacy and 55% coverage), the cumulative secondary infections will be reduced by more than half; however, NPIs are more effective than vaccinating 65% of the population. The presence of asymptomatic infections might affect the estimation of R but showed no significant effect on estimating transmission heterogeneity.ConclusionThe government should pay equal value to SARS-CoV-2 transmission in rural and urban areas and conduct specific prevention and control measures in rural areas. Older adults and children should receive particular attention in such policies, and community contact should be minimized. Moreover, the government must consider a country’s economy and governance when conducting vaccination and NPIs.