Yesterday (20 Apr), the Health Ministry (MOH) issued a press release with regard to an imported COVID-19 case discovered earlier this month.
A 43 year-old Indian expat on Work Pass arrived in Singapore from India on 2 Apr and was tested for COVID-19. Even though he was asymptomatic and had a negative pre-departure test taken on 31 Mar in India, his on-arrival swab was positive and he was immediately conveyed to a hospital.
On 4 Apr, his serology test result came back positive showing that it was an old infection. The authorities then deemed that the Indian expat was a recovered case based on his high Ct value which indicated a low viral load.
The authorities discharged him from the hospital on 6 Apr, as he was deemed to have been shedding only minute fragments of the virus RNA, which were no longer transmissible and infective to others.
Ten and twelve days later on 16 Apr and 18 Apr, the sister-in-law of the Indian expat and her husband were found to be infected with COVID-19. The three live together in the same household. The sister-in-law is a PR who works as an accountant at OM Universal Pte Ltd and her husband is also a PR who works as a manager at Spice Grill Restaurant and Rangoon Bar & Bistro.
In view of his sister-in-law infected with COVID-19, the Indian expat was tested again on 17 Apr. He tested positive for COVID-19. His Ct value of his polymerase chain reaction (PCR) was lower than his earlier test, indicating a higher viral load this time. His antibody titres are also currently very high, suggesting that he was exposed to a new infection which boosted his antibody levels.
MOH, in consultation with its expert panel, thought that the Indian expat was likely to have been re-infected with COVID-19. MOH said, “Our epidemiological investigations indicate that Case 61536 (Indian expat) was probably re-infected when he was in India, and had been infectious when he returned to Singapore. He then passed the infection to Cases 62045 (sister-in-law) and 62143 (husband of sister-in-law).”
MOH added that it is reviewing the border measures for recovered travellers.