The municipal Department of Health said the campaign aimed to contain infections and prevent further outbreaks during the rainy season and the final months of 2026.
Huynh Minh Chin, deputy director of the department, said both diseases remained endemic in the city and could spread rapidly under favourable conditions.
Health surveillance data as of October 30 showed that HCM City had recorded more than 42,500 dengue cases and 11 deaths in the first 10 months of the year.
Meanwhile, hand, foot and mouth disease cases exceeded 44,000, up more than 65 per cent from the same period last year, with five deaths and more than 1,600 outbreaks reported.
The circulation of enterovirus 71 (EV71), which can cause severe complications, has raised concerns about further outbreaks, particularly in preschools.
Chin warned that untreated mosquito breeding sites, poor sanitation and delayed detection of infections could accelerate transmission.
He urged local authorities to mobilise community groups for environmental clean-ups, eliminate potential mosquito breeding sites and strengthen inspections of high-risk areas.
Healthcare facilities were instructed to intensify disease surveillance, detect cases early and respond promptly to outbreaks.
Medical staff were also told to improve their ability to identify warning signs, arrange timely referrals and provide appropriate treatment to reduce severe cases and deaths.
The department stressed that insecticides should be used only when medically indicated and should not replace efforts to eliminate mosquito larvae.
Preschools, childcare centres and other educational facilities were instructed to monitor children's health daily, promptly report suspected hand, foot and mouth cases and regularly disinfect classrooms, toys, furniture and frequently touched surfaces.
Authorities also called for closer coordination between healthcare workers, schools and parents to limit transmission.
Residents were urged to inspect water containers at least once a week, remove items that collect standing water and eliminate mosquito larvae.
Families were also advised to wash their hands regularly with soap and clean children's toys and household surfaces.
Following the campaign launch, local authorities and community organisations inspected high-risk sites in Di An Ward, which has recorded a high number of infections and one dengue-related death.
Similar clean-up drives, inspections and outbreak control measures will be carried out across HCM City's wards, communes and special administrative zones.