PESHAWAR, Pakistan — Pakistan’s faltering effort to eradicate polio is threatening a multibillion-dollar campaign to wipe out the disease worldwide. Because of Pakistan, the virus is spreading to countries that were previously polio-free, UN officials say.
Five new polio cases surfaced in Pakistan in the first month of this year. Last year, Pakistan recorded 92 new cases, almost twice as much as Nigeria and Afghanistan — the only other polio-endemic countries, the World Health Organization said.
‘‘The largest polio virus reservoir of the world,’’ is in Peshawar in northwestern Pakistan, near the border with Afghanistan, according to WHO.
Fresh cases are showing up in countries that were previously polio-free, including Syria and Egypt, as well as in the Gaza Strip, said Ban Khalid Al-Dhayi, the spokeswoman for UNICEF in Pakistan.
‘‘A lot of countries that spent so much money and resources eradicating polio are worried,’’ Dhayi said in an interview.