Background The Pandemic of coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has critically impacted the spread of infection within nursing facilities. We evaluated the usefulness of genetic and serological tests conducted during a COVID-19 outbreak in a nursing facility in Japan. Methods After the first identification of SARS-CoV-2 infection, a comprehensive, facility- and/or unit-wide PCR testing from nasopharyngeal swabs was repeatedly performed in a three-unit facility including 99 residents with dementia and 53 healthcare personnel. Additionally, PCR testing was conducted separately for residents and staff with fever of ≥37.5 °C. Facility-wide serological testing, including rapid kit testing and quantitative assay, was conducted twice over 1 month apart. Results A total of 322 PCR and 257 antibody tests were performed. 37 (24.3%) of the 152 individuals (25/99 residents, 25.3%; 12/53 staff, 22.6%) were identified as PCR-positive. Seven residents died with a mortality of 7.1% (7/99). Among the 37 individuals, 10 (27.0%) were asymptomatic at the time of testing. PCR positivity was concentrated on one unit (Unit 1) (20/30 residents, 66.7%; 9/14 staff, 64.3%). The other units showed a limited spread of infection. In unit-wide and separate tests, PCR positivity detection was highly prevalent (22.9 and 44.4%, respectively) in Unit 1, compared with that in the other units. Serological testing identified two additional infected residents with a negative PCR result and showed that no staff was newly identified as infected. Conclusions Thorough PCR testing, in combination with comprehensive and separate tests, is critical for managing COVID-19 outbreaks in nursing facilities, particularly, in units considered an epicenter. Serological testing is also beneficial for tracing contacts, confirming the number of infected individuals, and authorizing the termination of the outbreak. Supplementary Information The online version contains supplementary material available at 10.1186/s12879-021-05972-5.
【저자키워드】 SARS-CoV-2, Antibody testing, PCR testing, COVID-19 outbreak, Nursing facility, 【초록키워드】 COVID-19, coronavirus disease, serological test, coronavirus, Mortality, SARS-COV-2 infection, Genetic, Infection, severe acute respiratory syndrome Coronavirus, Spread, Nasopharyngeal swab, Dementia, PCR testing, PCR, Serological tests, Asymptomatic, COVID-19 outbreak, Serological testing, outbreak, nasopharyngeal swabs, antibody tests, Fever, Japan, Antibody test, respiratory, Critical, PCR positivity, Combination, healthcare personnel, acute respiratory syndrome, supplementary material, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, infected individuals, epicenter, individual, PCR-positive, Negative PCR, unit, quantitative assay, termination, prevalent, Result, performed, caused, died, evaluated, conducted, individuals, number of infected, impacted, 【제목키워드】 serological,