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Background: Three clusters of coronavirus disease 2019 (COVID-19) linked to a tour group from China, a company conference, and a church were identified in Singapore in February, 2020., Methods: We gathered epidemiological and clinical data from individuals with confirmed COVID-19, via interviews and inpatient medical records, and we did field investigations to assess interactions and possible modes of transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Open source reports were obtained for overseas cases. We reported the median (IQR) incubation period of SARS-CoV-2., Findings: As of Feb 15, 2020, 36 cases of COVID-19 were linked epidemiologically to the first three clusters of circumscribed local transmission in Singapore. 425 close contacts were quarantined. Direct or prolonged close contact was reported among affected individuals, although indirect transmission (eg, via fomites and shared food) could not be excluded. The median incubation period of SARS-CoV-2 was 4 days (IQR 3-6). The serial interval between transmission pairs ranged between 3 days and 8 days., Interpretation: SARS-CoV-2 is transmissible in community settings, and local clusters of COVID-19 are expected in countries with high travel volume from China before the lockdown of Wuhan and institution of travel restrictions. Enhanced surveillance and contact tracing is essential to minimise the risk of widespread transmission in the community., Funding: None., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Influenza outbreaks occur periodically in Long Term Care Facilities (LTCFs) and vaccination is critical in preventing influenza infections. We evaluated the influenza vaccine effectiveness (VE) during respiratory outbreaks in LTCFs reported to the Ministry of Health, Singapore in 2017. A test-negative design was used to estimate the ratio of the odds of testing positive for influenza among vaccinated individuals to the odds among unvaccinated individuals. The VE was calculated as (1-odds ratio) × 100%. For adjusted VE, the estimates were derived using logistic regression adjusted for age group, gender, month of illness, and number of days from date of illness onset till to swab collection date. Estimates by influenza subtypes and post-vaccination time periods (15-180 days & 181-365 days) were also calculated using stratified data. 264 individuals, with 118 laboratory-confirmed influenza cases [32 A(H1N1)pdm09, 75 A(H3N2), 11 A(untypable)], were included in the analysis. No one was identified to be infected with influenza B. The overall adjusted VE estimate was 40.5% (95% CI: -12.2-68.5%), while the subtype-specific adjusted VE estimates were -43.4% (95% CI: -312.4-50.2%) against A(H1N1)pdm09 and 57.1% (95% CI: 5.7-80.5%) against A(H3N2). At 15-180 days post-vaccination period, the adjusted VEs were 59.3% (95% CI: 18.0-79.8%) against all influenza, 35.4% (95% CI: -123.5-81.3%) against A(H1N1)pdm09 and 67.9% (95% CI: 22.5-86.7%) against A(H3N2). Estimates were not significant at 181-365 days post-vaccination. The influenza vaccine showed varying effectiveness among individuals in Singapore's LTCFs in 2017, with a higher effectiveness among those who were more recently vaccinated. It remains an important tool in preventing influenza infections, especially for those who are at high risk of influenza-related complications., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Objective: Between February 2012 and May 2016, six residents of an 11-storey apartment block were diagnosed with MDR-TB. Based on initial tests, all isolates had similar genotypic profiles, although there were no identifiable epidemiological transmission patterns between three cases. We present findings from the cluster investigation and results of a mass screening exercise., Design: Free voluntary TB screening was offered to past and current residents of the apartment block, comprising an interview, Chest X-Ray, and Interferon Gamma Release Assay or Tuberculin skin test. Expected latent TB proportions were calculated using a reference population, and whole genome sequencing (WGS) was performed., Results: The index case was involved in a separate gaming centre outbreak involving five patrons. 241 current (67.9% of 355 residents) and 18 past residents were screened. The latent TB proportion was 19.9%, which was at the higher end of the expected range. WGS confirmed relatedness of cases' MDR-TB isolates- eight of 10 isolates were genetically identical, while the remaining two were one Single Nucleotide Polymorphism apart., Conclusion: With WGS, TB clusters not apparent through regular activity-based contact tracing may be detected. Mass screening may help inform the extent of transmission, but is limited by participation and difficulties in interpretation., (Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.)