SINGAPORE - Eight local cases of Covid-19 variants have been detected as at April 20, the Ministry of Health (MOH) said on Thursday (April 22), adding that necessary public health actions were taken promptly.

Seven of these cases are of the B117 variant - commonly known as the British variant - and one is of the B1351, or South African variant.

This solitary case works in the marine industry and was exposed to potentially infectious sources from ships visiting Singapore, said MOH, adding that all his close dormitory and workplace contacts have been placed on quarantine.

The seven cases with the British variant have been isolated and ring-fenced.

There was transmission to members of the same household for three out of these eight cases, but no further community spread has been detected, said MOH director of medical services Kenneth Mak at a Thursday briefing by the task force tackling the pandemic.

Singapore has also detected 342 imported cases of travellers from various countries carrying other variants.

Of these, 155 are of the British variant and 130 of the South African variant. Another 46 are of the B1617 or Indian variant, five of the B1525 variant and four of a Brazilian strain known as P1 (B11281).

Two other Brazilian strains - P2 (B11282) and P3 (B11283) - have infected one imported case each.

"All these cases have already been placed on stay-home notice or isolated upon arrival in Singapore," said Associate Professor Mak.

"We have not detected any further community spread for any of these other variants of interest.

"We continue to test all cases of Covid-19 infection that we've detected.

"But as more cases are reported, more testing is done, these numbers will change over time and in the future, we may provide further updates," added Prof Mak.