Dengue fever is on the rise in both Hanoi and Ho Chi Minh City, with new clusters emerging and increasingly severe cases reported, posing a serious challenge to Vietnam’s health system.

According to the Hanoi Center for Disease Control (CDC), between August 15 and 22, the city recorded 145 new dengue cases across 59 wards and communes - an increase of 26 cases compared to the previous week.

Notably, six new outbreak zones were identified in Lien Minh, Tuong Mai, Hai Ba Trung, Chuyen My, My Duc, and Ha Dong districts.

Health officials warn that the case count is trending upward, with some clusters showing multiple patients and high mosquito density, indicating a potential widespread outbreak in line with the annual dengue cycle.

Authorities have isolated and treated several hotspots, including Hamlet 2 in Khanh Ha (Thuong Tin), Van Giang village (My Duc), and Thuy Phu village (Chuyen My). My Duc alone reported 16 cases, followed by 10 in Lien Minh.

In addition to dengue, the city documented 64 hand-foot-mouth disease cases, 8 measles cases, and 6 COVID-19 cases in the same week - all slightly lower than the previous week. No new cases were reported for whooping cough, streptococcus suis, meningococcal disease, or Japanese encephalitis.

In response, Hanoi’s CDC instructed local clinics to intensify environmental sanitation, eradicate mosquito larvae, and spray insecticides in high-risk zones. They also ramped up surveillance and early case detection to prevent wider outbreaks.

Preventive efforts now include integrated monitoring of chikungunya fever, zoonotic diseases, and enhanced public education on mosquito-borne illnesses.

Ho Chi Minh City reports over 2,500 new dengue cases in a week

The situation is even more serious in Ho Chi Minh City. During week 33 (August 11 to 17), the city recorded 2,517 new dengue cases - a 38% spike compared to the previous four-week average.

So far in 2025, the city has reported 25,578 dengue infections. High-incidence wards include Thoi Hoa, Cu Chi, and Tan Hiep.

More worryingly, many patients are hospitalized late, some in severe condition, and some are misdiagnosed with respiratory or digestive illnesses, causing dangerous delays in treatment.

Hospitals report increasingly severe presentations. On August 22, Children’s Hospital in HCMC admitted a 7-month-old baby girl from Tay Ninh in critical condition due to severe dengue shock, respiratory failure, and coagulopathy.

The child had high fever for two days and was misdiagnosed with an upper respiratory infection at a private clinic. Upon hospital admission, she was lethargic, had low blood pressure, subcutaneous bleeding, a positive NS1 test, and a platelet count of only 21,000/mm³. She recovered after nearly 10 days of intensive care.

Another case involved a 12-year-old Cambodian boy hospitalized with high fever and abdominal pain. Hours after admission, he went into severe shock, with fluid leakage, low blood pressure, thickened gallbladder walls, and collapsed inferior vena cava. He recovered after 9 days of treatment.

Doctors caution that many parents mistakenly think their children have simple viral fevers and delay seeking care. However, dengue can cause dangerous complications such as shock, organ failure, and even death if not treated promptly.

Warning signs include persistent high fever, abdominal pain, nausea, nosebleeds, skin rashes, cold extremities, reduced urination, lethargy, or refusal to feed in infants. Parents are urged to bring children to medical facilities immediately upon observing these symptoms.

Experts emphasize that young children are at greater risk because their symptoms can resemble common colds, diarrhea, or hand-foot-mouth disease - leading to frequent misdiagnoses.

Early evaluation by pediatric specialists is crucial when unusual symptoms persist.

Proactive prevention and vaccine rollout underway

Health authorities advise citizens to take active measures against dengue, such as eliminating mosquito breeding grounds, sleeping under nets, cleaning stagnant water, and regularly changing water in vases or air conditioner trays.

Community participation is key in breaking the transmission chain, especially amid weather conditions that favor mosquito proliferation.

Vietnam is also rolling out the Qdenga dengue vaccine, which protects against all four dengue virus types. The vaccine is available at VNVC centers starting September 20 and is considered a “new weapon” in the country’s dengue prevention arsenal.

Common mild side effects may include swelling, redness, pain at the injection site, low-grade fever, fatigue, muscle pain, or headache, which usually resolve within 1–2 days. Rare but serious side effects such as anaphylaxis, severe thrombocytopenia, or prolonged inflammation at the injection site may occur.

Vaccinated individuals should remain at the clinic for at least 30 minutes post-injection to monitor and treat any adverse reactions. In case of symptoms such as fever over 39°C, severe headache, rashes, shortness of breath, facial swelling, or unusual bleeding, immediate medical attention is required.

Pre-vaccination screening is essential, and people with high fevers or acute illnesses should postpone vaccination. Those allergic to any vaccine component must inform medical staff. Pregnant women are not eligible for the vaccine.

Vaccination not only protects individuals but also helps reduce the risk of large-scale outbreaks. Its effectiveness depends on accurate information, adherence to medical guidance, and choosing trusted vaccination centers.

PV