Abstract
Background: Sars-CoV-2 outbreaks resulted in a high case fatality rate in nursing homes (NH) worldwide. It is unknown to which extent presymptomatic residents and staff contribute to the spread of the virus.
Aims: To assess the contribution of asymptomatic and presymptomatic residents and staff in SARS-CoV-2 transmission during a large outbreak in a Dutch NH.
Methods: Observational study in a 185-bed NH with two consecutive testing strategies: testing of symptomatic cases only, followed by weekly facility-wide testing of staff and residents regardless of symptoms. Nasopharyngeal and oropharyngeal testing with RT-PCR for SARs-CoV-2, including sequencing of positive samples, was conducted with a standardised symptom assessment.
Results: 185 residents and 244 staff participated. Sequencing identified one cluster. In the symptom-based test strategy period, 3/39 residents were presymptomatic versus 38/74 residents in the period of weekly facility-wide testing (P-value < 0.001). In total, 51/59 (91.1%) of SARS-CoV-2 positive staff was symptomatic, with no difference between both testing strategies (P-value 0.763). Loss of smell and taste, sore throat, headache or myalga was hardly reported in residents compared to staff (P-value <0.001). Median Ct-value of presymptomatic residents was 21.3, which did not differ from symptomatic (20.8) or asymptomatic (20.5) residents (P-value 0.624).
Conclusions: Symptoms in residents and staff are insufficiently recognised, reported or attributed to a possible SARS-CoV-2 infection. However, residents without (recognised) symptoms showed the same potential for viral shedding as residents with symptoms. Weekly testing was an effective strategy for early identification of SARS-Cov-2 cases, resulting in fast mitigation of the outbreak.
Keywords: COVID-19; nursing home; older people; presymptomatic; residents; staff.
【저자키워드】 COVID-19, nursing home, older people, presymptomatic, staff, residents, 【초록키워드】 SARS-CoV-2, SARS-COV-2 infection, Sequencing, viral shedding, Symptom, headache, RT-PCR, virus, Symptoms, observational study, Spread, SARS-CoV-2 transmission, Asymptomatic, outbreak, symptomatic, Cluster, Ct-value, Oropharyngeal, sore throat, Older, P-value, no difference, Fatality rate, symptomatic case, positive, Loss, effective, not differ, resulting, reported, conducted, contribute, Weekly, participated, presymptomatic resident, 【제목키워드】 SARS-COV-2 infection, outbreak, symptomatic, Metadata,