ISLAMABAD — Some 240,000 children have missed U.N.-backed vaccinations against polio because of security concerns in Pakistan's tribal regions bordering Afghanistan, a top official with the World Health Organization said Friday.


Dr. Nima Saeed Abid, the acting WHO chief in Pakistan, said health workers have not been able to immunize children in the North and South Waziristan regions – Taliban strongholds – since July 2012.


Pakistan is one of the few remaining countries, along with Afghanistan and Nigeria, where polio is rampant. As many as 58 cases were reported in Pakistan in 2012, down from 198 in 2011.


He said polio transmission is now concentrated in core endemic areas – central Khyber Pakhtunkhwa province, the Federally Administered Tribal Regions or FATA, parts of Karachi, Quetta and nearby Killa Abdullah and Pishin districts in south western Baluchistan province.


Abid said there have so far been five polio cases reported this year. These cases were reported from Karachi in Sindh province, Bannu and Malakand and Mardan in KPK province and from Mianwali in central Punjab province, added Abid, the acting WHO chief in Pakistan.


Abid said that 15 health workers have been killed in the anti-polio campaign in Pakistan since July 2012. Pakistani militant groups oppose the vaccinations and accuse the workers of spying for Washington.


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