New Delhi, Aug 7 - India has reported 163 polio cases so far this year and is among the four countries - Nigeria, Pakistan and Afghanistan, besides India - where the deadly paralytic disease continues to be endemic.

Informing the Rajya Sabha Friday, union Health Minister Ghulam Nabi Azad said only four countries in the world are endemic for polio and have never stopped transmission of the wild poliovirus.

'They are Nigeria, India, Pakistan and Afghanistan. In addition to these four endemic countries, there are 15 countries that have reported polio cases during 2009 so far,' the minister said.

'India does not account for maximum number of polio cases. Nigeria has reported more polio cases than India. During the year 2009 (till July 31), India has reported 163 polio cases compared to 349 polio cases in Nigeria. In 2008, India reported 559 polio cases while Nigeria reported 789,' the minister said.

In Pakistan till July 28, about 25 polio cases have been reported, while in 2008, it had 117 such cases.