SINGAPORE - A 43-year-old Indian national who had been discharged from hospital on April 6 after being deemed to be no longer infectious has been identified as a likely case of reinfection.
He then infected two others.
The two cases he has been linked to are an accountant, 41, and her husband, a 44-year-old restaurant manager at two eateries here.
They were reported as community cases on April 16 and April 18 respectively.
They are his sister-in-law and her husband.
This has prompted the Ministry of Health (MOH) to open a new local cluster around the three cases.
The man is here on a work pass and was classified as an imported case when he tested positive for the virus on April 2.
He had arrived from India.
He was taken to hospital, where he was assessed to have previously recovered from the virus based on his high CT value, which indicated a low viral load; his positive serology test result on April 4; and his negative pre-departure test taken on March 31, said MOH.
He was then discharged on April 6 without being required to isolate as he was deemed to be no longer infectious.
On April 17, he was identified as a close contact of his sister-in-law and subsequently tested positive for the virus.
In a release on Tuesday night (April 20), MOH, in consultation with an expert panel that comprises infectious diseases and microbiology experts, said it assessed that he was likely to have been reinfected with Covid-19 recently.
MOH added he was probably reinfected in India, and was infectious when he returned to Singapore.
It said: "With the emergence of new variants of concern around the world, we will closely monitor for reinfection of recovered Covid-19 cases, and are reviewing our border measures for recovered travellers.
"Similar imported cases suspected of reinfection will be isolated and undergo repeat Covid-19 PCR tests to monitor the trend of their viral loads, to ensure that such cases are detected promptly."
The authorities are unable to confirm when he suffered his first bout of the virus.
This is not the first case of Covid-19 reinfection in Singapore.
On Jan 25, a Bangladeshi, 28, tested positive for the virus after having recovered from it in June last year.