A foreign worker living in Riyadh wears a mask covering his mouth and nose on a main street in the Saudi capital on April 29, 2014 as the death toll from the newly emerged and often fatal Middle East Respiratory Syndrome (MERS) disease topped 100 in the desert kingdom. The health ministry reported more MERS cases in the city of Jeddah, prompting authorities to close the emergency department at the city's King Fahd Hospital. AFP PHOTO/FAYEZ NURELDINE        (Photo credit should read FAYEZ NURELDINE/AFP/Getty Images)