Mumbai, Apr 10 (IANS): Though India has not reported a single case of polio in the past two years, there is no room for complacency as the virus still exists in some neighbouring countries, an official said here Tuesday.

"Polio still exists in Afghanistan, Nigeria and Pakistan. The virus can travel to India as people move from one country to another. We have to be very cautious and pro-active to ensure that the virus does not re-enter our country," said Rajashree Birla, chairperson of Aditya Birla Centre for Community Initiatives and Rural Development.

She said the World Health Organisation (WHO) has advised India to maintain sensitive surveillance and ensure high childhood immunity against the wild polio virus.

"This is vital to ensure that no strain of polio is imported to our country until eradication is attained worldwide. In India, we have to continue the momentum," Birla said.

She was speaking at 'Championing the Polio Eradication Drive' with Maharashtra Governor K. Sankaranarayanan here. The drive is being carried out all over India in collaboration with the Government of India's Health Department, Municipal Corporation of Greater Mumbai, Aditya Birla Group and Rotary International.

The WHO declared India "polio-free" at a time when the world looked at India as the epicentre of the polio virus.

Birla said that around 15 years ago before the nationwide polio eradication drive was launched, nearly 200,000 children were crippled by polio every year.

The government, along with social groups and corporates, ensures that every child in the country is immunized and over 170 million children are administered pulse polio drops to tame the virus.