Uncovering the Impact of Control Strategies on the Transmission Pattern of SARS-CoV-2—Ruili City,Yunnan Province,China,February–March 2022

Introduction:The implementation of public health and social measures(PHSMs)was an effective option for controlling coronavirus disease 2019(COVID-19).However,evidence is needed to evaluate these PHSMs’effects on the recently emerged variant Omicron.Methods:This study investigated variant Omicron BA.2’s outbreak in Ruili City,Yunnan Province,China.The disease transmission dynamics,spatiotemporal interactions,and transmission networks were analyzed to illustrate the effect of PHSM strategies on Omicron spread.Results:A total of 387 cases were related to the outbreak.The time-varying reproduction number was synchronized with PHSM strategies.Spatiotemporal clustering strength presented heterogeneity and hotspots.Restricted strategies suppressed temporal and spatial relative risk compared with routine and upgraded strategies.The transmission network presented a steeper degree distribution and a heavier tail under upgraded strategies.Phase transformation and distinctive transmission patterns were observed from strategy-stratified subnetworks.Conclusions:The tightened response strategy contained reproduction of the virus,suppressed spatiotemporal clustering,and reshaped the networks of COVID-19 Omicron variant transmission.As such,PHSMs against Omicron are likely to benefit future responses as well.