The death toll for hand, foot and mouth disease (HFMD) has climbed to 81 among 32,588 cases in 52 cities and provinces, according to the Vietnam Administration of Preventive Medicine.
Tran Thanh Duong, the agency's deputy chief, told the Vietnam News Agency that fatalities have been reported in 17 cities and provinces, with Ho Chi Minh City having the highest toll at 22, followed by the provinces of Dong Nai, Binh Duong, Long An and Ba Ria-Vung Tau.
He added 96 percent of fatalities were of children under five.
Duong's office has warned the disease may continue to spread to more provinces and claim more lives in the coming months.
The risks are higher for children attending kindergartens, since the new school year has begun, it said.
The Ministry of Health has asked the education sector to take active measures to sterilize kindergartens, daycare centers and schools to prevent the spread of the HFMD virus.