As polio makes a comeback in Syria after a 14-year absence, health experts in Europe are warning that the disease could easily re-emerge on the continent as refugees from the war-torn Middle East flood in. Martin Eichner, a professor at the University of Tuebingen, warned in a letter to the medical journal The Lancelet that the disease could enter Europe via unsuspecting refugees, who could carry the virus without being affected by it. In addition to areas cut off from vaccination in Syria, polio has recently appeared in Africa, as well as sewage samples from Israel and Egypt. The polio virus is spread through feces, and currently has no cure. So far this year, 322 cases have been reported worldwide.