India was declared free of the wild polio virus in January 2011 however cases of flaccid paralysis continue to be reported in thousands from across the country.
“Inspite of the WHO declaring India polio-free, there has been an increase in the cases of non-polio paralysis. It is a huge cause of concern,” said Dr SD Gupta, president, IIHMR University.
In 2004, 12,000 cases of [allegedly] non-polio paralysis were reported which increased to 53,563 cases by 2012.
You can read more on the subject here: Bill Gates’ Polio Vaccine Program Caused 47,500 Cases of Paralysis Death
Environmental surveillance through testing of sewage samples for polio is also being done at Mumbai, Delhi, Bihar, West Bengal and Punjab.
Reference: Timesofindia.indiatimes.com