The highly infectious polio virus has been found in sewage samples in Gaza, putting thousands of Palestinians at risk of contracting a disease that can cause paralysis. Vaccine-derived poliovirus type 2 (VDPV2) has been identified at six locations in sewage samples collected on June 23 from Khan Younis and Deir al Balah, a World Health Organization spokesperson said in a statement Friday. “It is important to note the virus has been isolated from the environment only at this time; no associated...