The swine flu pandemic is only going to worsen in the coming months as the H1N1 virus, a subtype of influenza virus, is expected to spread the most during the monsoon and the winters but experts sought to allay fears saying though the virus is highly infectious, it has a low mortality rate.

"We fear the H1N1 virus will spread more. This is because of its nature — it takes only two days to spread. Though the virus is likely to spread more during the winter, the good news is mortality rate is low in cases of swine flu. There is nothing to panic. Usually, one influenza pandemic occurs between 10 to 40 years," said M Chakraborty, former head of the Indian Council of Medical Research and former director of School of Tropical Medicine.

According to Chakraborty, while the vaccine for swine flu will take five to six months to hit the market, even experts are uncertain how fast the virus will spread. In most cases in India so far, the effect has been mild and there are doubts if its ability to infect and virulence will change with time.

"Data has revealed that in most places across the world, H1N1 virus is seen to be rapidly replacing seasonal influenza. However, if one maintains the dos and don'ts, then the situation would be easy. There is a need to prioritise screening since the scare is making people randomly being referred for testing. Priority should be given to those who have symptoms and those who are high-risk individuals," said B Saha of School of Tropical Medicine.

State health department's nodal officer for swine flu, Ashish Biswas, said: "We need to make sure which patients need care first. The ID Hospital will have 90 beds in isolation ward within the next ten days while Bangur hospital will have 40 by the end of this month."