Three fliers from Dubai who had tested positive for the UK strain of the Covid-19 virus on arrival were discharged from the Infectious Diseases and Beleghata General Hospital on Thursday, officials of the health department said.

“We discharged the three after each tested negative in two confirmatory tests,” said an official. “All of them have been handed over certificates saying they are no longer Covid-19 positive.”

A few days ago, a flier found to be carrying the South African strain of the SARS-CoV-2 virus had been discharged from the hospital. “There are now six patients in the special ward that has been set up for such fliers from abroad,” said a doctor at the Beleghata hospital.

The fliers discharged on Thursday had reached Calcutta in late February and tested positive in the RT-PCR test, the samples for which were collected at the airport. Since these fliers, mostly in their late 30s and early 40s, were asymptomatic, the health department allowed them to go home with specific instructions for home isolation.

The swab samples of the fliers, who worked as labourers in Dubai, were later sent for a different test, which revealed they were carrying the UK strain.