An increase in polio in Pakistan is being linked to a secret CIA ploy used in the hunt for Osama bin Laden. With the help of a Pakistani doctor, the CIA set up a fake vaccination campaign in the city of Abbottabad in an effort to get DNA from the bin Laden family. A coalition of U.S. aid groups have written a letter to CIA head David Petraeus saying the covert program has cast doubt on the intentions and integrity of all humanitarian groups in Pakistan and undermined the international humanitarian community’s efforts to eradicate polio. Last year, Pakistan recorded the highest number of polio cases in the world.