COVID-19 Transmission among Healthcare Workers at a Quarantine Facility in Thailand: Genomic and Outbreak Investigations

Abstract

During the COVID-19 pandemic, Thailand implemented a quarantine program at approved quarantine facilities for every international traveler. Here, we report an epidemiological and genomic investigation of a COVID-19 cluster consisting of seven healthcare workers (HCWs) at a quarantine facility and its partnered hospital in Thailand. Outbreak investigations were implemented to obtain contact tracing data and to establish chains of transmission. Genomic sequencing of SARS-CoV-2 with samples within the cohort was performed. Investigations of 951 HCWs and staff with quarantined travelers were implemented to determine the chain of transmission. Genomic and outbreak investigations identified the international travelers infected with the B.1.1.31 SARS-CoV-2 lineage as the source of this outbreak. The genomic data and the investigated timeline revealed a putative transmission chain among HCWs, pointing toward the transmission via the use of common living quarters at the investigated quarantine site. The evaluation of this cohort has led to a policy recommendation on quarantine facility management. International travel quarantine is an important strategy to contain importation of COVID-19 cases. However, a quarantine facility is likely to become a potential hotspot, requiring thorough preventive measures. Reducing the exposure risk by providing private living quarters and scheduling clinical duties at a quarantine site separated from the conventional healthcare workforce have been implemented.

Prevalence and factors associated with COVID-19 among healthcare workers at a university hospital in Thailand

“…There are few published data on COVID-19 in Thai HCWs; these reports focused on the impact and outbreak of COVID-19 in healthcare facilities [12,13] and demonstrated the important of effective preventive measures for COVID-19. In Siriraj Hospital database from May 2020 to May 2021, there were 13,035 patients that met the criteria of “patient under investigation (PUI)” that underwent RT-PCR for SARS-CoV-2 and 705 (5.4%) were confirmed to have COVID-19.…”

Risks and challenges in COVID-19 infection prevention and control in a hospital setting: perspectives of healthcare workers in Thailand

“…Adaptation of physical space and working environment is therefore crucial in response to some implementation measures, including weather conditions and social distancing (31). A recent study on an outbreak investigation reported transmission among HCWs at a quarantine facility in Thailand, and suggested use of thorough prevention measures and setting up private living quarters to reduce exposure risk for HCWs whilst performing their clinical work (32). In Malaysia, HCWs were also found to be particularly at risk at work when COVID-19 was not suspected in patients and insufficient PPE was worn (33), recommending that occupational health check-ups should be conducted to obtain information about the epidemiology of COVID-19 among HCW.…”

Risk of within-hotel transmission of SARS-CoV-2 during on-arrival quarantine in Hong Kong: an epidemiological and phylogenomic investigation

“…6 Transmission of infection from quarantined guests to other guests or staff has also been reported elsewhere and is now well-documented. Nine studies 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 have reported investigations of within-hotel transmission of SARS-CoV-2 between guests and/or staff, though most were conducted to investigate individual outbreaks where suspected transmission had occurred, and only five combined both genomic and epidemiologic data in their investigation. 7 , 8 , 9 , 10 , 11 Regular testing of hotel guests and staff can help to identify infections more quickly and limit leaks into the community.…”

“…Nine studies 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 have reported investigations of within-hotel transmission of SARS-CoV-2 between guests and/or staff, though most were conducted to investigate individual outbreaks where suspected transmission had occurred, and only five combined both genomic and epidemiologic data in their investigation. 7 , 8 , 9 , 10 , 11 Regular testing of hotel guests and staff can help to identify infections more quickly and limit leaks into the community. However, it can be challenging to identify transmission between quarantined persons because those who test positive in HQ would typically be assumed to have acquired their infection before they entered quarantine and therefore go unrecognised.…”