Control of an outbreak of COVID-19 at a tertiary hospital in Taiwan

Background: Coronavirus disease 2019 (COVID-19) has circulated in Taiwan since late 2019. Healthcare facilities are vulnerable to COVID-19 outbreaks due to clusters of symptomatic patients and susceptible hosts. Prompt control of outbreaks is crucial. In May 2021, an index case of COVID-19 was detected at Far Eastern Memorial Hospital (FEMH) in New Taipei City, Taiwan, 3 days after hospital admission, spreading to 26 patients and staff. Herein we evaluate control of this COVID-1 outbreak. Methods: To control the outbreak, the index case ward was closed, and large-scale COVID-19 testing (RT PCR) was performed for all inpatients, caregivers and healthcare workers (HCWs). All exposed persons were quarantined. Thorough investigation was conducted to analyze the transmission route. Results: The outbreak comprised 12 patients, 12 caregivers, and 3 HCWs. Seven patients expired and the remaining cases recovered. Overall, 456 patients/caregivers and 169 HCWs were quarantined. Analysis showed that longer exposure time was the main cause of HCW infection; all three infected HCWs were primary-care nurses related to the index case. To diminish hidden cases, all hospitalized patients/caregivers received PCR examinations and all results were negative. Thereafter, all patients/caregivers routinely received PCR examination on admission. Hospital-wide PCR screening for HCW detected 4 positive HCWs unrelated to this outbreak, and a second-round of screening detected 2 more cases, with no additional cases during the following 6 months. Conclusion: Prompt infection control measures and large-scale PCR screening can control a COVID-19 outbreak within 2 weeks. Exposure time is the major risk factor for HCW infection.