Kolkata | Both the nurses who tested positive for Nipah virus were admitted to the Beliaghata ID Hospital in Kolkata, a senior state health department official said.

One was brought to the hospital on Tuesday night, while the other, a house staff member, was shifted from Burdwan Medical College and Hospital early Wednesday, he added.

"The health condition of both of them remains extremely critical. They are still in a coma and admitted to the ICCU," the official of the health department told PTI.

Incidentally, a resident medical officer (RMO) at Barasat hospital, who had been in contact with the infected nurses, also showed symptoms of Nipah, he said.

"The RMO has been placed under isolation, though tests conducted at the Virus Research and Diagnostic Laboratory (VRDL) at Kalyani AIIMS, including nasal swab, blood, urine, and throat swab, came back negative," he added.

According to state health department sources, one of the nurses recently returned from her hometown in Katwa in Purba Bardhaman district, where she fell ill and was initially admitted to a local hospital on December 31.

"As her condition worsened, she was transferred to the Bardhaman Medical College, and then by a special ambulance to the Barasat hospital before being moved to Beliaghata ID Hospital," an official said.

A source said the other nurse had a history of travelling to Ghugragachi in Nadia district, which is located near the India-Bangladesh border.

Nipah virus is a notifiable disease, requiring immediate reporting to the central government.