An outbreak of COVID-19 in Bach Mai Hospital, the Major Tertiary Care Hospital in Hanoi, Vietnam, March 2020: Implications for prevention

Tóm tắt

Vietnam experienced an outbreak of COVID-19 at Bach Mai hospital, a major tertiary referral hospital in March 2020. We describe the findings of the outbreak investigation for the purpose of informing future prevention measures. We defined hospital - related COVID-19 cases as those that tested positive with SARS-CoV-2 RNA using the polymerase chain reaction (PCR) test during March 4 - 20, 2020 and had been exposed to the hospital in the 14 days before symptom onset or before a positive PCR. We interviewed all COVID-19 cases on their exposure time and analyzed them for epidemiologic links. We performed whole - genome sequencing (WGS) among those whose Cycle - Threshold values were <30. Of 36 COVID-19 cases identified, ages ranged from 21-88 years; 10 (28%) remained asymptomatic. We identified cases among food-service workers (23, 64%), family members (6, 17%), inpatients (4, 11%), healthcare workers (2, 6%), and household contacts (1, 3%). Fourteen (39%) had spent 14 days in the hospital before diagnosis. We identified 3 clusters of cases consisting of 3 (2 healthcare workers, 1 household contact, the earliest cases), 7 (neurology department), and 23 cases (all food-service workers). Of 17 WGS - available strains, 14 had identical sequences; the remaining 3 differed by 1 - 2 nucleotide changes. The introduction of SARS-CoV-2 into the hospital likely occurred at an outpatient screening clinic, while rapid spread may have been facilitated by food-service workers. To prevent outbreaks of COVID-19 in healthcare settings, infection prevention and control and routine screening among healthcare workers, including auxiliary groups such as food - service staff should be strengthened.