SARS-CoV-2 Variants Detection Strategies in Wastewater Samples Collected in the Bangkok Metropolitan Region.

Wastewater surveillance is considered a promising approach for COVID-19 surveillance in communities. In this study, we collected wastewater samples between November 2020 and February 2022 from twenty-three sites in the Bangkok Metropolitan Region to detect the presence of SARS-CoV-2 and its variants for comparison to standard clinical sampling. A total of 215 wastewater samples were collected and tested for SARS-CoV-2 RNA by real-time PCR with three targeted genes (N, E, and ORF1ab); 102 samples were positive (42.5%). The SARS-CoV-2 variants were determined by a multiplex PCR MassARRAY assay to distinguish four SARS-CoV-2 variants, including Alpha, Beta, Delta, and Omicron. Multiple variants of Alpha-Delta and Delta-Omicron were detected in the wastewater samples in July 2021 and January 2022, respectively. These wastewater variant results mirrored the country data from clinical specimens deposited in GISAID. Our results demonstrated that wastewater surveillance using multiple signature mutation sites for SARS-CoV-2 variant detection is an appropriate strategy to monitor the presence of SARS-CoV-2 variants in the community at a low cost and with rapid turn-around time. However, it is essential to note that sequencing surveillance of wastewater samples should be considered complementary to whole genome sequencing of clinical samples to detect novel variants.

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

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.

Mortality among foreign nationals in Chiang Mai City, Thailand, 2010 to 2011.

BACKGROUND: Up to 65% of travelers to less developed countries report health problems while traveling. International travel is an increasing concern for health practitioners. To date, there have not been any published analyses of mortality amongst foreign nationals visiting Thailand. Our objectives are to examine the magnitude and characterize the deaths among foreign nationals in Chiang Mai, a popular tourist province in Thailand. METHODS: The study commenced with a review of the Thai death registration. Death certificates were retrieved, reviewed, and classified by the causes of death. Basic statistics and proportionate mortality ratio (PMR) were used to describe the pattern of deaths. Standardized mortality ratio (SMR) was used to assess the excess mortality risk among foreign nationals. RESULTS: Between January 1, 2010 and May 31, 2011, there were 1,295 registered deaths in Chiang Mai City, of which 102 records (7.9%) were foreign nationals. Median age of decedents was 64 years (range 14-102 y). Female-to-male ratio was 1 : 5.4. The highest mortality was among Europeans (45.1%). Most of the deaths were natural causes (89.2%) including 36 cardiac diseases (PMR = 35.3) and 20 malignancy diseases (PMR = 19.6). Deaths due to external causes were low. The SMRs range between 0.15 and 0.30. CONCLUSION: Communicable diseases and injuries were not the leading causes of death among foreign nationals visiting Chiang Mai, Thailand. It is essential that travelers are aware of mortality risk associated with their underlying diseases and that they are properly prepared to handle them while traveling.