Hand, foot and mouth disease has killed about 450 children a year in China over the past decade and remains a threat, according to a senior public health specialist.

Wang Huaqing, chief immunization scientist for the Chinese Center for Disease Control and Prevention, said more than 13 million cases were reported on the Chinese mainland between 2009 and 2015, mostly in children under 5.

Since 2008, medical institutions have been required to report any instance of the infectious disease to health authorities. A national epidemic-surveillance network found more than 80 percent of the cases were among toddlers younger than 3.