KARACHI, Oct 31 (Reuters) - Insecurity on the Afghan border is to blame for the increase in polio cases in Pakistan as unchecked cross-border movement affects an immunisation drive, a health official said on Tuesday. Twenty-eight cases of polio have been reported in Pakistan this year, World Health Organisation official Nimba Abid said. Pakistan is among just nine polio endemic countries in the world. The virus, which typically affects children under the age of five, causes irreversible paralysis. "It is difficult for us to reach the security sensitive areas in the Pakistani tribal areas where there is also extensive population movement across the Afghanistan border," Abid told Reuters. "Last year we had a total of 28 cases. This year we already have the same number although we are vaccinating around 29 million children in each nationwide drive," he said. Health experts have warned more than 250,000 people could contract polio every year if Pakistan, Afghanistan, Nigeria and India fail to eradicate the virus and meet current eradication targets.
