TY - JOUR T1 - [Transmission chains of local epidemic of COVID-19 caused by 2019-nCoV Delta variant in Zhenhai district, Ningbo]. AU - Chen,Y, AU - Yan,K D, AU - Zhang,D L, AU - Yi,B, AU - Wang,A H, AU - Lei,S, AU - Hong,H, AU - Chu,Y R, AU - Xu,G Z, PY - 2022/7/20/entrez PY - 2022/7/21/pubmed PY - 2022/7/22/medline SP - 1044 EP - 1048 JF - Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi JO - Zhonghua Liu Xing Bing Xue Za Zhi VL - 43 IS - 7 N2 - Objective: To investigate the local epidemic of COVID-19 caused by 2019-nCoV Delta variant in Zhenhai district of Ningbo, identify the transmission chain and provide reference for the prevention and control of COVID-19 epidemic. Methods: The incidence data of COVID-19 in Zhenhai from 6 to 18 December, 2021 were collected in field investigation. Field epidemiological investigation was conducted to understand the epidemiological characteristics of COVID-19 cases and analyze the transmission chains. Results: The first case might be infected with 2019-nCoV through direct or indirect exposure when passing through a medium-risk area, then a family cluster was caused, and the epidemic spread through close contacts of family members with others such as work, daily life, and moxibustion. The epidemic lasted for 14 days, and 74 confirmed COVID-19 cases were reported. The median incubation period was 4.0(3.0,5.8)d. All the cases were in a chain of transmission for more than 6 generations, and the intergenerational interval was 3.5(2.0,5.3)d. The gene sequencing result indicated that the pathogen was Delta AY.4 variant of 2019-nCoV. Both the epidemiological investigation and the gene sequencing results supported that the local COVID-19 epidemic in Zhenhai was associated with the COVID-19 epidemic in Shanghai. Conclusions: The transmission chain of this epidemic was clear. Delta AY.4 variant has obvious characteristic to cause case clusters in families, places with poor ventilation, and residential communities. It is suggested to strengthen the health management in key areas and key populations, and increase the frequency of nucleic acid testing. SN - 0254-6450 UR - https://www.unboundmedicine.com/medline/citation/35856197/[Transmission_chains_of_local_epidemic_of_COVID_19_caused_by_2019_nCoV_Delta_variant_in_Zhenhai_district_Ningbo]_ DB - PRIME DP - Unbound Medicine ER -