NEW DELHI, Nov 23 (Reuters) - A poor immunisation drive and widespread filth in India's most populous state of Uttar Pradesh have fuelled a polio outbreak, killing about two dozen children and affecting nearly 450 this year, the health minister said. "The quality of immunisation rounds in districts of western Uttar Pradesh ... was not of the desired quality leading to many children being missed," Anbumani Ramadoss said in a statement to parliament on Thursday. The prevalance of non-polio entrovirus in the stomachs of children living in the state's crowded and unsanitary towns interfered with the efficacy of oral polio drops, leading to a spike in cases in 2006, he added. More than 500 cases of polio were reported this year from across the country, 443 in Uttar Pradesh alone, he said. The polio outbreak in Uttar Pradesh, home to more than 170 million people, has fuelled fears that it could undermine global efforts to eradicate the disease, which is incurable and leads to irreversible paralysis among children. The WHO has said the Uttar Pradesh strain of the virus had spread to neighbouring Nepal and Bangladesh besides faraway Angola and Nambia. All four nations had been polio free. India has stepped up efforts to combat polio by roping in thousands of extra volunteers to administer polio drops, especially in Uttar Pradesh where thousands of children were missed in earlier immunisation rounds. Besides poor hygiene, a campaign by some of the state's Muslims that polio drops were part of a western conspiracy to make their children sterile have undermined efforts to stamp out the disease, officials say. But international experts say new vaccine strategies could wipe out hotspots in north India by the end of the decade. Scientists at the Imperial College, London, said last week that switching to a monovalent vaccine against the dominant strain in India from the standard trivalent one that protects against three types of polio virus, is key. They said the problem with the trivalent vaccine, especially in the unhygienic conditions of many Indian towns, was that the three strains could interfere with one another inside the body, producing immunity to one strain but not the others. The Indian health minister said authorities had begun to change their strategies. "Monovalent oral polio vaccine 1 is being used in high-risk districts and states as it produces higher immunity as compared to the trivalent polio vaccine," Ramadoss said.
