India reaches milestone of no cases of wild poliovirus for 12 months

India, one of the world’s four endemic countries (the others being Pakistan, Afghanistan, and Nigeria) for transmission of wild poliovirus, has experienced a year without reporting any cases for the first time. The last case—of wild poliovirus type 1 (WPV1)—was recorded on 13 January 2011 in the state of West Bengal.

WHO launched the Global Polio Eradication Initiative in 1988 and intensified its efforts to “finish the job of eradication” in the four endemic countries by the end of 2012. To achieve eradication a country has to be polio free for three consecutive years.

Achieving 12 months free of wild polio cases has been a gargantuan effort for Indian health authorities. More than 900 million doses of oral poliovirus were administered to Indian children in 2011: more than 172 million children under 5 were vaccinated during two national immunisation days held every year; an additional seven sub-national immunisation days were held during which about 120 million children received the vaccine; and extra mop-up activities occurred whenever cases of wild polio or vaccine derived polio were suspected.

Rigorous surveillance of acute flaccid paralysis, house to house immunisation of children missed on immunisation days, and robust communication strategies targeting migrant and mobile groups have also help India reach the milestone of 12 months.

India has seen a massive drop in polio cases from 741 in 2009 to one in 2011. No cases of wild poliovirus type 1 have been reported since Nov 2009 in Uttar Pradesh and Bihar, both of which were polio endemic, and no cases of wild poliovirus type 3 have been recorded since April 2010. However, there were seven cases of vaccine derived polio in India in 2011.

By contrast, Nigeria still has all three polio strains in circulation, while Afghanistan and Pakistan have reported nine and three cases, respectively, so far this year.