VDPVs are extremely rare and are detected in children with immunodeficiency or in populations with low levels of immunization.
"VDPVs are different from wild polio viruses and India has not reported any case of polio due to a wild polio virus since January 2011," said the ministry.
"A total of 741 children had gotten paralyzed due to the wild polio virus in 2009 in India accounting for over half of the global polio cases against this backdrop, India's success in keeping children free from any wild polio virus for the last more than two years is being globally acclaimed as a major public health achievement," it said.
The WHO removed India from the list of polio endemic countries in 2012 following one year without any case due to wild polio virus in the country. Having completed more than two years without the wild polio virus, India has moved closer to a polio-free certification in early 2014.
"The Government of India and the States have been focusing on intensifying routine immunization to minimize the risk of VDPVs. The response is consistent with the global strategy.
"The most important strategy for prevention of emergence of VDPVs is achieving and maintaining high routine immunization coverage with OPV doses among infants," said Keshav Desiraju, Secretary, Department of Health and Family Welfare, Government of India.
To achieve higher routine immunization rates and protect children against all vaccine preventable diseases, the government declared 2012-13 as 'Year of Intensification of Routine Immunization'.
In 2013, the government is holding four 'Special Immunization Weeks' in the 411,129 high risk areas identified by the polio eradication programme. These areas comprise of slums, nomadic sites, construction sites, brick kilns and other areas housing people on the move, who often miss out on immunization due to their transient nature.
These special immunization weeks in April, June, July and August are aimed at protecting the vulnerable populations with all vaccines available under routine immunization, including tOPV. Of the 411,129 high risk areas, 82,965 are in Maharashtra.
WHO Representative Dr Nata Menabde said, "India's polio surveillance programme is geared to detect VDPVs as part of AFP surveillance system supported by World Health Organization."
Detection of VDPVs will not impact the polio eradication certification process. The pre-requisites for polio free certification of a region includes absence of wild polio virus in all countries of the region for three consecutive years, presence of certification standard surveillance and the completion of laboratory containment activities.
Though India has not reported any case of polio for over two years, an importation of wild polio virus remains the larger threat to the children in India, especially in view of close proximity to polio endemic Pakistan and Afghanistan, Dr Menabde said.
To ensure eradication of wild polio virus and minimize the risk of emergence and circulation of VDPVs, the Government of India is working in coordination with the Global Polio Eradication Initiative on the polio end game strategy.
A group of experts headed by the Indian Council of Medical Research (ICMR) has been formed to work on this strategy, the government said.
--IBNS (Posted on 24-06-2013)