How many dengue cases does Vietnam have each year?

It varies a lot. WHO reported 184,903 cases and 43 deaths in Vietnam in 2025, and 131,202 cases to 20 September 2026. The biggest year in our table was 2019, with more than 320,700 cases.

When is dengue season in Vietnam?

Dengue occurs all year, but cases rise in the rainy season. In 2019 WHO and the Ministry of Health linked a sharp rise to the start of the rains.

Which part of Vietnam has the most dengue?

The south usually has the most. WHO said the southern region made up about 71 percent of reported cases in 2026, though Hai Phong in the north had the most cases in 2024.

Is there a vaccine for dengue in Vietnam?

Yes. Qdenga was licensed by Vietnam's drug regulator on 14 May 2024, and patients pay for it privately. Whether it suits a given person is a question for a doctor.

What are the warning signs of severe dengue?

WHO lists severe stomach pain, vomiting that does not stop, fast breathing, bleeding gums or nose, blood in vomit or stool, restlessness, extreme thirst, and pale cold skin. WHO says these signs need medical care straight away.

Dengue Fever Vietnam: Seasons, Cases and Testing Since 2015

What dengue is

The World Health Organization (WHO) describes dengue as a viral infection spread by the bite of infected mosquitoes, mainly the Aedes aegypti mosquito, which bites during the day. Most people who catch it have no symptoms or a mild illness and get better in one to two weeks. A few develop severe dengue, which needs hospital care and can be fatal.

When symptoms come, WHO says they usually start 4 to 10 days after infection and last 2 to 7 days. They can include a high fever, a severe headache, pain behind the eyes, muscle and joint pain, nausea, vomiting, swollen glands and a rash. People infected for a second time are at greater risk of severe dengue.

Sources: World Health Organization, Dengue and severe dengue fact sheet.

Four virus types

There are four types of dengue virus, and all four circulate in Vietnam, according to the Ministry of Health's Department of Preventive Medicine. Types 1 and 2 are the most common. Type 2 made up 88 percent of cases in 2023 and about 70 percent in 2024, and it is often linked to severe cases and outbreaks.

This matters because a person can catch dengue more than once, from a different type each time. WHO says people infected for a second time are at greater risk of severe dengue.

Sources: VietnamNet, Ministry proposes adding dengue vaccine in expanded immunisation programme, 14 November 2024; World Health Organization, Dengue and severe dengue fact sheet.

Cases by year since 2015

Vietnam's Ministry of Health counts cases and shares them with WHO. The table below gathers the figures we could trace to a published source. Some years only have a figure for part of the year, and for three years we could not find a full year total in a source we could read, so those rows say so.

Year	Reported cases	Deaths	Period covered
2015	No full year figure found in a source we could read		none
2016	No full year figure found in a source we could read		none
2017	181,054	30	Year, reported in late December
2018	No full year figure found; the 2019 total was reported as double 2018		none
2019	more than 320,700	53	Full year
2020	84,411	13	First 10 months
2021	50,473	18	To early October
2022	about 270,300	108	To late October
2023	167,437	46	To 15 December
2024	138,342	26	To 15 December
2025	184,903	43	Full year
2026	131,202	18	To 20 September

Two patterns stand out. Big years come in waves: 2019 and 2022 were far above the years either side. And deaths are low compared with cases. WHO says early detection and access to proper medical care greatly lower death rates from severe dengue. The Ministry of Health's later figure for 2024 was about 141,000 cases and 28 deaths, and its figure for 2025 was about 181,200 cases and 36 deaths; the WHO figures in the table come from WHO's own updates and may include later corrections.

Figures for 2017 to 2022 come from Vietnamese news reports quoting the Ministry of Health; 2023 to 2026 come from WHO Western Pacific situation updates. Periods differ, so compare years with care.

Sources: VietnamPlus, Dengue fever treatment remains weak: official, December 2017; VietnamNet, Health ministry raises alarm over dengue fever (2019 total); VietnamPlus, Vietnam reports over 84,400 dengue fever cases in 10 months, 3 November 2020; Tuoi Tre News, Vietnam records 18 deaths by dengue fever since beginning of 2021, 7 October 2021; The Star (Vietnam News/ANN), Vietnam records over 270,000 cases of dengue fever in 2022, 29 October 2022; WHO Western Pacific, Dengue Situation Update 714, 9 January 2025; WHO Western Pacific, Dengue Situation Update 737, 8 January 2026; WHO Western Pacific, Dengue Situation Update 756, 15 October 2026; Viet Nam News, Treating and preventing infectious diseases will be increasingly complex next year, December 2024; Viet Nam News, Complex dengue situation highlights need for proactive prevention, 2026.

When the season peaks

Dengue is present all year in Vietnam, but it rises with the rains. WHO and the Ministry of Health warned in July 2019 that the rapid start of the rainy season was driving cases up, with the biggest rises in the south, the Central Highlands and the central coast. Mosquitoes breed in standing water, and WHO's Vietnam office pointed out that something as small as a bottle cap can hold enough.

In 2026, WHO reported that the southern region accounted for about 71 percent of cases nationwide. In 2024, the Ministry of Health said Hai Phong in the north recorded the most cases, more than 23,000, followed by Ho Chi Minh City with more than 14,000. So the south carries most cases in most years, but no region is free of dengue.

Sources: WHO Viet Nam, Dengue increase likely during rainy season, Ministry of Health, WHO warn, 16 July 2019; WHO Western Pacific, Dengue Situation Update 756, 15 October 2026; Viet Nam News, Treating and preventing infectious diseases will be increasingly complex next year, December 2024.

How Vietnam defines a case

WHO's regional reports include each country's case definition. For Vietnam, a suspected case is a sudden fever lasting 2 to 7 days, plus at least two signs such as bleeding, headache, loss of appetite, nausea or vomiting, rash, muscle or joint pain, pain around the eyes, tiredness, or stomach pain. In routine surveillance, the Ministry of Health guideline tests at least 7 percent of clinical cases in a laboratory.

So the national numbers count many cases diagnosed by doctors from symptoms, with a share confirmed by laboratory tests. That is one reason to read the totals in the table as trends rather than exact counts.

Sources: WHO Western Pacific, Dengue Situation Update 756, 15 October 2026.

Warning signs WHO lists for severe dengue

WHO lists these signs of severe dengue, which often come after the fever has gone, and says people who have them need medical care straight away:

severe stomach pain;
vomiting that does not stop;
fast breathing;
bleeding gums or nose, or blood in vomit or stool;
tiredness, restlessness or feeling very weak;
being very thirsty, or pale and cold skin.

WHO's Vietnam office adds a point on timing: it says urgent care is needed when, a few days into a very high fever, the temperature drops suddenly and any of these signs appear. Vietnam's ambulance number is 115.

Sources: World Health Organization, Dengue and severe dengue fact sheet; WHO Viet Nam, Dengue increase likely during rainy season, Ministry of Health, WHO warn, 16 July 2019.

How testing works

Dengue is confirmed with a test, not by symptoms alone. WHO says that in the first week of illness the virus can be found directly, with molecular tests, antigen tests (often called NS1 tests) or rapid diagnostic tests. Antibody tests are also used. Which test is used depends on how long the illness has lasted, and that choice is made by a doctor.

WHO says there is no specific medicine for dengue, and that early detection and access to proper medical care greatly lower the death rate from severe dengue. WHO also warns that some common painkillers can raise the risk of bleeding in dengue.

If you need somewhere for a first visit, our family clinic picks are one place to start.

Sources: World Health Organization, Dengue and severe dengue fact sheet.

Prevention and the vaccine

WHO says prevention relies mainly on controlling mosquitoes and avoiding bites, especially during the day. Its advice includes emptying or covering anything that holds water around the home once a week, window screens, and insect repellent.

Vietnam's drug regulator licensed a dengue vaccine, Qdenga, on 14 May 2024, and people pay for it themselves. In November 2024 the Ministry of Health was considering adding a dengue vaccine to the free national immunisation programme. Whether a vaccine suits you is a question for a doctor; our vaccines for Vietnam guide covers the wider vaccine picture.

This guide is education based on WHO and Ministry of Health data. It does not diagnose or treat anyone. Questions about your own health are for a doctor.

Sources: World Health Organization, Dengue and severe dengue fact sheet; VietnamNet, Ministry proposes adding dengue vaccine in expanded immunisation programme, 14 November 2024.

Common questions

How many dengue cases does Vietnam have each year?: It varies a lot. WHO reported 184,903 cases and 43 deaths in Vietnam in 2025, and 131,202 cases to 20 September 2026. The biggest year in our table was 2019, with more than 320,700 cases.
When is dengue season in Vietnam?: Dengue occurs all year, but cases rise in the rainy season. In 2019 WHO and the Ministry of Health linked a sharp rise to the start of the rains.
Which part of Vietnam has the most dengue?: The south usually has the most. WHO said the southern region made up about 71 percent of reported cases in 2026, though Hai Phong in the north had the most cases in 2024.
Is there a vaccine for dengue in Vietnam?: Yes. Qdenga was licensed by Vietnam's drug regulator on 14 May 2024, and patients pay for it privately. Whether it suits a given person is a question for a doctor.
What are the warning signs of severe dengue?: WHO lists severe stomach pain, vomiting that does not stop, fast breathing, bleeding gums or nose, blood in vomit or stool, restlessness, extreme thirst, and pale cold skin. WHO says these signs need medical care straight away.

Sources

Figures checked against these sources. Our method.