Health experts have expressed concerns over the new cases of Swine flu (H1N1) infections in Pune in Maharashtra.

Doctors pointed out the changing temperature were the reason behind the return of the H1N1 virus. Some of the hospitals in the city have already sent samples of suspected swine flu patients to the National Institute of Virology for verification.

Doctors say that an early detection of eh virus n important in treatment and that the strain's variation is the reason for the reemergence of the infection. State surveillance officer, Dr Pradip Awate aimed to calm people in neighboring Mumbai, pointed out that there is not reason to panic as there has been no case of swine flu in Mumbai.

"There will be sporadic cases of swine flu from time to time, but there is no need to hit the panic button. This is definitely not an indication of an outbreak," Awate said.

People have been advised to exercise caution and get checked. Health sector experts held a meeting on Thursday decided to strengthen surveillance and involve private sector players to check the infection.