Hand, foot and mouth disease (HFMD) has killed nine children in Ho Chi Minh City so far this year, according to the HCMC Preventive Health Center.
The disease took only one life in the southern metro last year.
Doctor Nguyen Dac Tho, the center's deputy director, said the number of infected patients is still rising.
An estimated 200 children have been admitted to the HCMC Children's Hospitals No.1 and 2 this month, nearly doubling the number of last month.
Tho said most of HFMD cases recorded across the country originated from the southern region.
It is because the disease is contagious through digestive and respiratory systems, and there are more factors that cause digestive diseases in the south than those in the north, he explained.
A virus causes HFMD and symptoms include a fever, loss of appetite, sore throat and rashes on the hands and feet.
Preventive measures to avoid the disease include frequent hand washing and being sanitary when dealing with food.