India fights back against type-1 polio strain

India is likely to win the fight against the most dangerous strain of polio, with no cases reported this year in the badly hit Uttar Pradesh. India is the focus of concern among the global health community after an outbreak of 676 cases in 2006 — a tenfold jump over 2005 and one-third of the world's total. The Indian strain caused countries such as Angola and then Namibia to be re-infected, and is thought to be the source of the first outbreak in seven years in neighbouring Myanmar. Around 96 per cent of India's cases in 2006 were of the virulent type-1 strain that paralyses around 1 out of every 200 children infected and travels over wide areas. The majority of cases were reported in western Uttar Pradesh, which is India's most populated state, with 170 million people, and one of its poorest. The state and neighbouring Bihar are considered fertile grounds for the polio virus to flourish, with their tropical climate, crowded towns, poor sanitary conditions, high birth rates and widespread diarrhoea among children. The Health Minister, Dr Anbumani Ramadoss, said that with constant efforts there have been no cases of type-1 polio in western Uttar Pradesh in the last six months. India, which aims to eradicate polio by the end of 2008, has seen 103 cases of polio this year against 150 till the end of June last year, but, more importantly, type -1 cases in the first six months have fallen to 39 against 145 year-on-year. Crucially, no child has been affected by the type-1 strain in the seven worst-affected districts of Uttar Pradesh this year. A member from the WHO's National Polio Surveillance Project in India said that a transition point has been reached in the fight against the type-1 virus, and once this is taken care of, the next step would be to eradicate the type-3 virus. As a result of the greater focus on immunising children against type 1 there has been a spike in the cases of less virulent type-3 polio, which should not cause alarm, as the first step is to get rid of type 1. In the past, a trivalent vaccine that protects against all three types of polio was used in India, but it was not effective enough against the virulent type-1 strain. As a result, a monovalent vaccine specifically aimed at the type-1 strain has been put to use in many areas. The type-3 strain paralyses 1 in around 1,000 children infected, and does not travel so far. Apart from India, polio still lingers in Pakistan, Afghanistan and Nigeria.