A postgraduate science student from Maharashtra, who had recently returned to his institute in Bengal after classes resumed, tested positive for Covid-19 last week and was admitted to the ID Hospital in Beleghata.

The state health department has sent his swab sample to the School of Tropical Medicine to find out whether he is infected with a mutant strain of the SARS-CoV-2 virus.

The student, who got his swab sample collected at the Calcutta airport, is in the same ward at the ID Hospital where fliers from Dubai who have tested positive for the UK and South African strains of the virus have been admitted.

Doctors said on Monday evening the student’s condition was stable.

Health department officials said two fliers who had been earlier admitted to the hospital after testing positive for the British strain of SARS-CoV-2 were discharged on Monday. One of them returned home to Digha in East Midnapore and the other to Baruipur in South 24-Parganas. Earlier, a flier from Dubai who had tested positive for the South African strain had been discharged.

Health department officials said the student from Maharashtra had reached the institute in Bengal on March 10. After he was found to be positive, district health officials alerted the health department and he was shifted to the Beleghata facility. “We want to find out whether the student has been infected with a mutant strain. There is no reason to panic and the patient is doing fine,” said a health department official.

With several fliers from Dubai arriving in Calcutta testing positive, the health department has decided to tap the facility available at the School of Tropical Medicine to test some of the samples that need early detection.

Usually, samples that tested positive in an RT-PCR test at the airport are sent to the National Institute of Biomedical Genomics in Kalyani for analysis of the strain.

Officials said the Kalyani institute was burdened with samples and it would take at least three to four days for a report to reach the health department. Sometimes, results would remain “inconclusive”.

“To hasten the confirmation of the strain in this particular case (related to the student from Maharashtra), we opted for the School of Tropical Medicine,” an official said.

The Beleghata facility has eight patients who had flown in from Dubai and tested positive on their arrival. They have been admitted to the facility where the student, too, has been admitted.