Outbreak Investigation of COVID-19 Transmission Among Healthcare Workers Who Worked at an Alternative State Quarantine Facility, Bangkok

Abstract

On December 5, 2020, Institute for Urban Disease Prevention and Control Institute(IUDC) had reported a confirmed case of COVID-19  by a private hospital as a healthcare worker working in an alternative state quarantine Facility(ASQ). IUDC and The Division of Epidemiology conducted an investigation on 5 December 2020 -9 January 2021 to confirm the diagnosis of COVID-19, the epidemiological of the disease and propose measures for disease control and prevention. The descriptive epidemiological studies were conducted, consisting of 1) the study of personal characteristics, general information, clinical data and risk factors by interviewing patients and infection control nurses. 2) Active case finding the exposure in the hospital, ASQ Roommates and family  by defining 4 types of  definitions: suspected , confirmed, High-risk and low risk exposure  from 23 November to 30 December 2020 3) COVID 19 detection and immunity laboratory studies 4) ASQ Environmental studies by interviewing general managers and staff in the quarantine facility. The results of the study showed 7 confirmed patients working in rotation in the ASQ 1 and ASQ 3, were 3 and 2 cases respectively. One person was responsible for measuring the fever of quarantined patients in the room, conducted nasopharyngeal swab  3 samples from quarantined patients and one who collected the quarantine samples with COVID-19 infection. Door knob, bathroom, nursing room where ASQ1 found the genetic material of the coronavirus 2019. Results of active case finding from 37 high-risk people were found in their families, work, accommodation, and colleagues. Laboratory tests showed COVID 19 among two high-risk people, 35 were not found. Results of the IgG, IgM immunity test against SARS-CoV2 in 29 ASQ workers were alll non-reactive. A common point source COVID-19  was identified in medical personnel operating in ASQ, Bangkok. The most likely sources of the outbreak to be due to exposure during quarantine sample collection and fever measurements of three infected Russians whom detected COVID-19 and transmitted to a colleague while having meals together and sharing in the same accommodation. The virus strain of  detected person showed that it was the same as the Russians whom detected COVID-19. After disease control and surveillance for 2 incubation periods, no additional cases were reported. Disease control in ASQ requires strict adherence to the standard of infection control. And there is constant control, supervision, monitoring, and evaluation continuously.