Polio

Fighting in Afghanistan and Pakistan meant that polio eradication did not go well in those countries in 2007, a World Health Organization report said last week. They are two of the last four nations that have not eliminated the disease. In Afghanistan, most cases were in southern provinces under Taliban control. In Pakistan, many were in the remote tribal border areas, where Osama bin Laden is still being pursued and local militants are battling the government. Polio experts see the territory differently: as one "epidemiological block" with two transmission corridors, one in the mountainous north , where cases of the polio strain known as Type 1 are common, and one in the flatter south, where Type 3 prevails.