Vietnam steps up dengue prevention as disease patterns evolve

The event took place on June 10, organised by the Health & Life Newspaper in collaboration with Takeda Vietnam Pharmaceuticals, in observance of ASEAN Dengue Day on June 15.

The discussion featured Dr. Vo Hai Son, deputy general director of the Vietnam Administration of Disease Prevention under the Ministry of Health; Dr. Angela Pratt, head of World Health Organization (WHO), Vietnam Country Office; and Assoc. Prof. Dr. Nguyen Thanh Hung, deputy director of the Vietnam Paediatric Association and Former Director of Children’s Hospital 1.

Experts provided key insights and perspectives on the dengue fever situation. Photo: the Health & Life Newspaper

Dengue fever, ranked by the WHO among the world's top 10 public health threats, saw global cases surge tenfold from 2010 to 2019.

In Vietnam, the disease has spread nationwide. Many localities in the North that previously had no cases now report dengue fever, most notably during the 2022 outbreak, which sent hundreds of patients to hospitals across the northern provinces.

"The Aedes aegypti mosquito, which spreads dengue fever, thrives in warmer, wetter conditions and urban environments," said Pratt. "Three factors are driving this shift: climate change creating ideal breeding conditions for this mosquito; rapid urbanisation with unsynchronised infrastructure in densely populated areas; and the increasing difficulty in forecasting the disease, which challenges the health system in preparation and proactive response."

From a management perspective, Son stated, "The outbreak cycle has a tendency to shorten. The 2022 peak recorded 371,000 cases nationwide, and in subsequent years the country has continued to record an average of roughly 150,000 cases annually."

However, according to the representative of the Vietnam Administration of Disease Prevention, the disease no longer follows old patterns. In 2025, cases increased again but did not decrease at the end of the year as usual – November and December remained at high levels. As a result, the first five months of 2026 recorded over 50,000 cases, 2.5 times higher than the same period last year.

Dr. Vo Hai Son, deputy general director of the Vietnam Administration of Disease Prevention. Photo: the Health & Life Newspaper

Abnormal weather patterns, characterised by alternating hot, humid, and continuous rainfall since the beginning of the year, are ideal conditions for mosquitoes to breed.

"More concerningly, the DENV-2 serotype is currently dominant, increasing the risk of many severe cases," Son added. "Dengue prevention efforts will become increasingly difficult without determination and the synchronous implementation of many solutions to protect and care for health."

A significant change is that dengue fever is no longer just a disease of children – now anyone, at any age, can be infected. "More than 10 years ago, 60–70 per cent of dengue cases in the south were children under 15. Now, the incidence rate between children and people over 15 is almost equal," Hung said. "In other words, anyone in the family can contract dengue."

"The biggest barrier lies in complacency itself," he added. "Most people are aware of dengue fever yet still think of it as someone else's problem. When a high fever strikes, they self-medicate, and many young people believe the disease is not serious for them."

Meanwhile, dengue fever progresses in a way that contradicts common perception. The third to fifth day – when the fever has decreased and the patient thinks they have recovered – is the stage that can be the most dangerous. This is when the disease is most prone to becoming severe, with complications such as dengue shock syndrome, severe haemorrhage, and multi-organ failure. This combination of complacency and the disease's deceptive nature has led to many cases being detected too late, increasing the risk of death.

“There are families who have lost two children at the same time in one season because they were detected too late. Even though the health sector has tried its best, there are still cases where we could not save the children,” said Hung.

The burden of dengue extends far beyond case numbers. According to Hung, even severe cases that are successfully treated can leave lasting after-effects in both adults and children – ranging from memory impairment, difficulty concentrating, insomnia, and depression to hair loss and vision disorders.

Severe cases requiring dialysis or mechanical ventilation can cost hundreds of millions of VND, sometimes up to VND500–600 million ($20,000–24,000), creating great pressure on the healthcare system. The disease also weighs heavily on patients' families, forcing relatives to take days off work for round-the-clock care while causing prolonged anxiety and stress.

Over the past half-century, the fight against dengue fever has mainly relied on vector control (killing mosquitoes, killing larvae, eliminating breeding sites) and epidemiological surveillance – this remains the foundation and the first line of defence.

Currently, several new prevention tools are emerging. According to Pratt, early warning systems are increasingly improving thanks to technology and AI, helping to forecast transmission trends more accurately. Along with that, vaccines are becoming a proactive preventive tool, helping to reduce the risk of infection and the risk of severe progression, thereby reducing the burden of treatment and mortality.

"There's a vaccine now registered in Vietnam, and a pilot will happen soon to try rolling it out in a public health drive," said Pratt. "I'm personally very excited to see the results of that pilot because this is an essential new tool in the toolbox."

Dr. Angela Pratt, Head of WHO, Vietnam Country Office. Photo: the Health & Life Newspaper

"With the support of international organisations and businesses, the health sector is researching the implementation of a pilot dengue vaccination scheme in some localities to serve as a basis for evaluation before considering inclusion in the expanded immunisation drive," Son said. "In parallel, the health sector continues to promote mosquito control, communication, improve treatment capacity, and gradually apply environmental and weather data for early epidemic warning. New tools do not replace existing measures – they supplement them in a comprehensive prevention strategy."

The WHO has set a global target to achieve zero preventable deaths from dengue fever by 2030. According to Pratt, the key is to bridge the gap between information, awareness, and action: messages need to be clear, easy to understand, and actionable, accompanied by a capable health system.