A superspreading event involving a cluster of 14 coronavirus disease 2019 (COVID-19) infections from a family gathering in Hong Kong SAR (China)

Abstract

Objectives: An outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in Wuhan, China in December 2019, with subsequent spread around the world. Hong Kong, a Special Administrative Region of China, recorded its first confirmed case on 23 January 2020. In this report, we describe a family cluster of 12 confirmed cases with 2 additional confirmed cases from secondary transmission. Method: We reported the epidemiological, clinical and laboratory findings of the family cluster and the public health measures instituted. Results: All 12 confirmed COVID-19 cases were among the 19 attendees of a 3-hour Chinese New Year family dinner consisting of hotpot and barbecue. Environmental sampling of the gathering venue was negative. 2 additional confirmed cases who were the co-workers of 2 confirmed cases were later identified, indicating secondary transmission. Contact tracing, quarantine and environmental disinfection were instituted to contain further spread. Discussion: Our findings are highly suggestive of a superspreading event during the family gathering. The source is likely one of the cases during the asymptomatic phase. It attested to the high infectivity of SARS-CoV-2 through human-to-human transmission from social activities and argued for the necessity of social distancing in curtailing the disease spread.

Keywords

• coronavirus disease 2019
• sar-cov-2
• virus
• outbreak
• social distancing
• hong kong
• novel coronavirus