Abstract
Household transmission is a primary source of SARS-CoV-2 spread. We used COVID-19 epidemiologic investigation data and viral genome analysis data collected in the city of Kyoto, Japan, during January 2020-June 2021 to evaluate the effects of different settings and viral strains on SARS-CoV-2 transmission. Epidemiologic investigations of 5,061 COVID-19 cases found that the most common category for close contact was within households (35.3%); this category also had the highest reverse transcription PCR positivity. The prevalent viral lineage shifted from B.1.1.214 in the third wave to the Alpha variant in the fourth wave. The proportion of secondary cases associated with households also increased from the third to fourth waves (27% vs. 29%). Among 564 contacts from 206 households, Alpha variant was significantly associated with household transmission (odds ratio 1.52, 95% CI 1.06-2.18) compared with B.1.1.214. Public health interventions targeting household contacts and specific variants could help control SARS-CoV-2 transmission.
Keywords: COVID-19; Japan; SARS; SARS-CoV-2; contact tracing; coronavirus; coronavirus disease; epidemiology; household contact; respiratory infections; severe acute respiratory syndrome coronavirus 2; viral genome; viruses; zoonoses.
【저자키워드】 COVID-19, coronavirus disease, severe acute respiratory syndrome coronavirus 2, viruses, respiratory infections, SARS-CoV-2, coronavirus, Epidemiology, SARS, Contact tracing, Japan, household contact, zoonoses., viral genome, 【초록키워드】 coronavirus disease, respiratory infections, zoonoses, variant, Contact tracing, Intervention, Transmission, severe acute respiratory syndrome Coronavirus, Spread, SARS-CoV-2 transmission, Health, household, Lineage, Households, Public health interventions, Japan, household transmission, Alpha variant, reverse transcription PCR, household contacts, viral genome, close contact, Odds ratio, Contact, primary source, viral strain, viral strains, acute respiratory syndrome, 95% CI, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, COVID-19 case, city, help, secondary cases, viral genome analysis, secondary case, Public, prevalent, Kyoto, highest, collected, significantly, proportion, evaluate the effect,