The city recorded 1,338 cases from August 31 to September 6, bringing the year-to-date total to 31,032, according to the HCM City Centre for Disease Control (HCDC).
Weekly cases have remained above 1,000 since early August, with Chanh Phu Hoa, Minh Thanh and An Nhon Tay among areas reporting high infection rates.
Le Hong Nga, deputy director of HCDC, said dengue is now endemic year-round in HCM City, where humid weather, alternating rain and sunshine and high population density create favourable conditions for Aedes mosquitoes to breed.
She warned that Aedes aegypti mosquitoes do not breed only in polluted or damp areas, but commonly lay eggs in containers holding clean water in and around homes.
Flower vases, plant pots, gutters, bottles and other items holding even small amounts of stagnant water can become breeding sites, meaning residents of houses and high-rise apartments remain at risk.
Mosquito eggs can survive dry conditions for long periods and develop once exposed to water. Under favourable conditions, mosquitoes can develop from eggs to adults in about a week.
HCDC advised households to spend 10-15 minutes each week checking water containers, changing water in flower vases, covering or turning over unused containers and removing items that can collect water.
Nguyen Tran Nam, deputy director of City Children's Hospital, warned that early dengue symptoms can be mistaken for a common fever, while self-treatment could delay necessary medical care.
Infants, children with obesity, people who have previously had dengue and those with chronic heart, kidney, lung or neurological conditions face a higher risk of severe illness.
The most dangerous stage typically occurs between the third and seventh days of illness, when fever may begin to subside. Warning signs include lethargy, abdominal pain, repeated vomiting, breathing difficulties, cold hands and feet and bleeding.
There is no specific treatment for dengue. Health experts warned against intravenous fluids at home or the use of aspirin and ibuprofen, which can increase the risk of bleeding.
Experts also recommended combining mosquito and larvae control with vaccination for eligible people, while stressing that vaccines do not provide complete protection or replace environmental measures.