The HCM City Centre for Disease Control (HCDC) said on October 3 that the city recorded 1,491 dengue cases in week 39, from September 21-27, broadly unchanged from the average of the previous four weeks.
Cumulative cases since the beginning of 2026 have exceeded 35,700. Con Dao Special Zone and Chanh Phu Hoa and Minh Thanh wards recorded among the highest infection rates per 100,000 people.
At a recent HCDC seminar, experts highlighted three groups particularly vulnerable to severe dengue: older people, children, especially infants and those who are overweight, obese or have underlying conditions, and pregnant women.
Dr Than Ha Ngoc The, vice chairman of the HCM City Geriatrics Association, said ageing weakens immune function and physiological reserves, while conditions such as hypertension and cardiovascular or chronic kidney disease can complicate treatment.
Symptoms in older patients can also be atypical. Instead of high fever or pronounced aches, they may experience restlessness, drowsiness or confusion, making the disease harder to recognise.
Dr Truong Huu Khanh, former head of the Infection-Neurology Department at Children's Hospital 1, said infants under one year old and children who are overweight, obese or have underlying conditions also face increased risks. Symptoms in infants can be difficult to detect before their condition suddenly deteriorates.
Pregnant women require close monitoring because dengue can lead to complications including postpartum bleeding, premature birth and low birth weight.
Experts warned that severe dengue can also affect young, healthy people. HCM City Hospital for Tropical Diseases recently treated critically ill patients aged 16 and 21, while a 20-year-old dengue patient died in September.
The most dangerous phase of dengue typically occurs between the third and seventh days of illness, when fever may already have subsided. Without timely treatment, patients can develop shock or severe organ damage.
Warning signs include severe abdominal pain, repeated vomiting, bleeding, drowsiness, reduced urination and cold extremities. Older patients may also experience confusion or breathing difficulties.
Health experts urged residents to eliminate mosquito breeding sites, prevent mosquito bites and seek medical attention promptly if symptoms develop.