Patna, March 14 - The battle against polio is far from over in Bihar, which has the highest incidence of the disease in India and recorded 99 new cases in the first 40 days of 2008.

This is an alarming rise compared to only 11 cases in the first two months of 2007. Currently, 25 of 38 districts in Bihar are in the grip of the polio virus.

\'The state recorded 89 new cases of polio in the first two months - and 10 cases till March 11, compared to the figure of 11 last year. There is all possibility that polio cases will go up in the coming months,\' a health department official said, while not wanting to be identified.

Most new cases were reported from Samastipur -, Darbhanga -, Muzaffarpur -, Madhubani -, Saharsa -, Vaishali -, Purnea -, Khagaria - and Nalanda - districts.

Unofficial sources put the figure of polio cases at over 140 till the first week of March.

India, which recorded 864 cases last year, is the number one polio endemic country in the world with Bihar and Uttar Pradesh - described as \'sick\' states for their poor economic and social parameters - recording the highest incidence. Bihar surprised many with its high 396 cases in 2007 as against just 61 in 2006.

The target of eradicating polio in Bihar remains a big challenge for national and international organisations, including Unicef and WHO as the new cases have surfaced despite millions of rupees being spent on a series of immunisation drives.

\'It will be a long time before polio is eradicated from Bihar,\' a health official associated with Unicef told IANS.

According to official records, several rounds of immunisation drives as well as special immunisation rounds were carried out in January and February this year, but the results were poor.

The state government with the help of WHO, Unicef and the Indian National PolioPlus Committee has identified 72 blocks for an intensified anti-polio campaign to eradicate the disease from Bihar by the end of 2008.

Health officials say that detection of polio cases caused by the P3 strain of the virus is a big challenge. Unlike the P1 strain, it hardly responds to the vaccine.

The disease, which is passed on through the faecal-oral route, affects children up to five years of age. It causes paralysis of the limbs and can be fatal in severe cases.