JINAN -- Heze City in east China's Shandong Province is stepping up prevention efforts for hand, foot and mouth disease (HFMD), after it was confirmed as the cause of death for two babies.

A seven-month-old baby died Sunday 10 hours after he was rushed to the Heze Infectious Disease Hospital and a 15-month-old boy died Monday in the People's Hospital of Juancheng County.

The disease was found in all the nine counties and districts in the city, said Li Shixin, an official of Heze City Health Bureau. He added another four babies died of cephalitis or suspected HFMD from March 8 to March 23.

All children aged under seven years old have been registered and offered free medical disinfectants, the local health authorities said Thursday.

The families would conduct a week-long disinfection with instructions from medical staff. The local government also ordered morning check-ups and quarantine at child-care centers.

Small clinics and hospitals which diagnose children with symptoms of the highly contagious disease should send the patients to 12 designated hospitals.

According to the Ministry of Health, HFMD can be caused by a host of intestinal viruses, but EV71 and the Coxsackievirus (Cox A16) were the most common.

HFMD usually starts with a slight fever followed by blisters and ulcers in the mouth and rashes on the hands and feet. Those with EV71 often show serious symptoms. It can also lead to meningitis, encephalitis, pulmonary edema and paralysis in some children. There is no vaccine.