Singapore said yesterday it used a new type of test never administered before to find the link between two seemingly unrelated outbreaks of the virus on the island.
Calling the diagnostic a “world-first,” the Health Ministry said yesterday that it was able to match specific antibodies in different patients rather than the virus itself to determine that infections spreading in two religious communities originated in a married couple visiting from virus ground zero.
Officials said the couple from Wuhan, China, spread the infection to a married Singaporean couple at the Life Church and Missions, who then infected a man working for the Grace Assembly of God at a Chinese New Year event.
“Using two different antibody testing platforms … the team at Duke-NUS Medical School proved that the two suspect Cases 83 and 91 were indeed infected with COVID-19 in late January 2020, as they had very high levels of the virus-specific antibodies in their blood,” the ministry said in a statement of tests on the Singaporean couple. The husband and wife became cases No. 83 on Feb. 19 and 91 three days later, respectively.
More than 20 cases have been linked to the Grace Assembly of God and at least eight to Life Church and Missions, making up about a third of Singapore’s 91 known infections as of Wednesday morning. The concentrated incidents of infection are referred to as “clusters.”
Where they both originated from remained unknown until the antibody test.
The Singaporean couple had symptoms for weeks prior their infections were confirmed, the ministry said, citing health records. The wife sought treatment at Sengkang General Hospital while her husband went to a clinic in late January.
“This result was a significant piece of evidence which confirmed the links between the church clusters and the two Wuhan travellers,” the ministry added.
Using the data, health officials were able to piece together the course the virus took from Wuhan to the two church groups. The married Chinese couple arrived Jan. 19 and that day attended the church where they met the Singaporean couple. Ten days later, the Chinese couple tested positive for what would soon be dubbed COVID-19.
The Singaporean couple then infected the Grace Assembly of God employee on Jan. 25 at a Chinese New Year gathering on Mei Hwan Drive. That church worker, aka Case No. 66, tested positive Feb. 14.