Cluster C
The Ministry of Health in Singapore identified two people from Singapore (C3 and C4), with no recent travel history to China, who tested positive for SARS-CoV-2 from enhanced pneumonia surveillance. Activity mapping showed that both individuals had visited the same church on Jan 19, 2020. C5 was identified through active case-finding. Two other people with COVID-19 were subsequently linked to this cluster (C1 and C2, who are husband and wife). These individuals were Chinese nationals from Wuhan who arrived in Singapore on Jan 19, 2020. Re-interviews with C1 and C2 found they had also visited the church on the same day. All five people were asymptomatic during the church visit (figure 1 lower panels).
The church is an independent church that occasionally receives a few visitors from China at the Mandarin service conducted every Sunday.11 Although C1 and C2 were not church members, they attended the 2-h morning service when they travelled to Singapore. They left immediately after the service and did not report having lunch at the church. Based on closed-circuit camera findings, C5 occupied the same seat as did cases C1 and C2 at the prayer meeting after the morning service, but they did not recall meeting each other.
Among the 227 regular church members, 191 members were contacted, of whom 142 attended the church on Jan 19, 2020. Of these people, only two had travel history to Guangdong, China, 14 days before Jan 19, 2020; both reported being well. Six were unwell and referred for further management and none tested positive for SARS-CoV-2. 93 close contacts were placed under quarantine.
No additional cases linked to any of the three clusters were identified as of Feb 14, 2020.