Ho Chi Minh City, Dong Nai, Dong Thap, Tay Ninh, Lam Dong, Danang and Hanoi recorded the country's highest case numbers over the past four weeks, according to the Ministry of Health.
Children under five, mostly of nursery and kindergarten age, accounted for more than 87 per cent of infections.
The ministry said cases of hand, foot and mouth disease and other infectious diseases, including dengue fever and COVID-19, could continue to rise in the coming period.
In an urgent notice sent to the Ministry of Education and Training and local authorities on September 4, the health ministry called for stronger disease prevention measures at educational institutions, particularly nurseries and kindergartens.
Schools were asked to improve hygiene, keep classrooms well ventilated and adequately lit, and regularly clean classrooms and frequently touched surfaces.
Nurseries and kindergartens were urged to follow the ministry's "three clean" principle – clean food and drink, clean living environments and clean hands.
The ministry also called for greater efforts to help parents and teachers recognise symptoms of hand, foot and mouth disease and other infectious illnesses and take appropriate preventive measures.
Local education and health authorities were asked to work closely to promptly detect, handle and report suspected or confirmed cases among children and students.
