Representatives of a number of airlines recommended that passengers refrain from flights to Southeast Asia, where the number of cases of dangerous viral disease was growing. In some airports in the region, passengers put on special masks and respirators. The World Health Organization announced that the nature of the virus, which causes a severe form of pneumonia, is still unclear, and the disease is a "global threat." In Vietnam and China, at least 9 people died from illness, hundreds of people in serious condition. Cases of the disease are also noted in Canada. In Germany, a sick passenger flying from Singapore was hospitalized.