Family clusters have contributed significantly to the onward spread of SARS-CoV-2. However, the dynamics of viral transmission in this setting remain incompletely understood. We describe the clinical and viral-phylogenetic characteristics of a family cluster of SARS-CoV-2 infections with a high attack rate, and explore how whole-genome sequencing (WGS) can inform outbreak investigations in this context. In this cluster, the first symptomatic case was a 22-month-old infant who developed rhinorrhoea and sneezing 2 days prior to attending a family gathering. Subsequently, seven family members in attendance at this event were diagnosed with SARS-CoV-2 infections, including the infant described. WGS revealed indistinguishable SARS-CoV-2 genomes recovered from the adults at the gathering, which were closely related genetically to B.1 lineage viruses circulating in the local community. However, a divergent viral sub-lineage was recovered from the infant and another child, each harbouring a distinguishing spike substitution (N30S). This suggested that the infant was unlikely to be the primary case, despite displaying symptoms first, and additional analysis of her nasopharyngeal swab revealed a picornavirus co-infection to account for her early symptoms. Our findings demonstrate how WGS can elucidate the transmission dynamics of SARS-CoV-2 infections within household clusters and provide useful information to support outbreak investigations. Additionally, our description of SARS-CoV-2 viral lineages and notable variants circulating in Ireland to date provides an important genomic-epidemiological baseline in the context of vaccine introduction.
【저자키워드】 COVID-19, SARS-CoV-2, Family cluster, Outbreak investigation, Whole-Genome-Sequencing, 【초록키워드】 whole-genome sequencing, Vaccine, SARS-COV-2 infection, variant, Local, Symptom, virus, Symptoms, Spread, Nasopharyngeal swab, family, Characteristics, outbreak, SARS-CoV-2 genome, attack rate, Co-infection, Transmission dynamics, Lineage, Community, Cluster, Ireland, Viral transmission, WGS, information, SARS-CoV-2 infections, Analysis, Support, circulating, symptomatic case, B.1 lineage, Seven, SARS-CoV-2 viral, described, significantly, diagnosed, unlikely, provide, suggested, contributed, notable, displaying, baseline, 【제목키워드】 household transmission, epidemiological, Analysis,