Kolkata, Aug 18 - A two-and-a-half-year-old boy was on ventilator support as the number of confirmed swine flu cases in West Bengal increased to 56 Tuesday.

'Six cases were confirmed in the morning and three more in the evening. The total number of swine flu cases in the state is now 56,' Tapas Sen, the state's nodal officer for swine flu, told IANS.

Two-and-a-half-year-old 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.

A niece of former Indian skipper Sourav Ganguly, 11-year-old Sneha, 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, Sen added.

She tested positive for swine flu Monday.

There have been no death from the virus in the state so far.

With only two designated swine flu hospitals in the metropolis, the state health department plans to open an isolation ward at one more hospital in the satellite township of Salt Lake.