A two-and-a-half year old critically ill boy was on ventilator support while former Indian cricket captain Sourav Ganguly’s niece remained stable as the number of confirmed swine flu cases shot up to 53 in West Bengal on Tuesday.

“Six people tested positive for the Influenza A(H1N1) virus Tuesday, and the total number affected is now 53,” Tapan Sen, the state’s nodal officer for swine flu, said.

Mr. Sen said that Akash Chowdhury, under treatment at the intensive care unit of the state—run R.G. Kar Medical College and Hospital, was put on ventilator support as his condition had become critical.

Eleven year old Sneha, daughter of Soruav Ganguly’s elder brother, was “stable” and “making satisfactory progress” at the swine flu isolation ward of the state-run M.R. Bangur hospital in the south of the city, he added.

She tested positive for swine flu Monday.

The state has not reported any death from the virus so far.

With only two designated swine flu hospitals -- M.R. Bangur and Infectious Diseases Hospital -- in the metropolis, the state health department plans to open an isolation ward at one more hospital in the satellite township of Salt Lake.