Three persons, including an Army doctor, were on Sunday detected with the coronavirus infection here – in the first case of a medico getting afflicted with the dreaded Covid-19 in West Bengal, where the disease count has now gone up to 21.

The 52-year-old anaesthesiologist is now admitted at the Command Hospital, Alipore, state Health Department sources said.

A 66-year-old man from north Kolkata also tested positive for the disease.

The third victim, a resident of Hooghly district now admitted at a private hospital, was detected with the disease on Sunday night.

Health Department sources said the anaesthesiologist had gone to Delhi earlier this month. On his return, he joined duty at the Command Hospital, and worked till March 21 when he felt unwell.

He was admitted to the hospital with cold, fever and respiratory problems, with the doctors initially suspecting it to be a case of pneumonia. However, as his condition did not improve, the doctor’s swab sample was sent for testing at the National Institute of Cholera and Enteric Diseases (NICED). On Sunday, the test results came as positive.

Sources said the doctor was kept in the isolation ward since his admission as a precautionary measure.

Efforts are on to track the patients he had treated and also the doctors and other hospital staff who had come in close contact with him, and send them to quarantine. The authorities were also trying to find out the persons he had met during his Delhi visit.

The north Kolkata resident is learnt to have visited Madhya Pradesh recently. A source said his brother is also suffering from fever, and has been tested for the infection. The results are awaited.

The third patient, in his late 50s, had been suffering from fever for some time. He travelled by train despite his indisposition to his office in Durgapur of West Burdwan district for a couple of days till his condition deteriorated. He was hospitalised on Saturday following a further deterioration in health.

One person has died due to Covid-19 in the state so far.