Dengue: Symptoms, Duration and Treatment of This Global Epidemic

Find out how long dengue lasts, how it can be treated, and what to do about it. Key information on symptoms, prevention, and the global dengue epidemic.

[This post was written by Adelaida Sarukhan and Daniel Camprubí.]

Imagine a disease that can suddenly disrupt your daily life. It begins with seemingly mild symptoms, such as fever and headache, but in some cases, it can develop into a potentially life-threatening illness with no specific treatment. Now imagine that 4 billion people (half of the world’s population) are at risk of contracting it.

Dengue, a mosquito-borne viral infection, has become an alarming global epidemic affecting millions of people across continents. While many of us have heard of it, the current surge in dengue cases demands our attention more than ever.

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Better understanding dengue dynamics: how long does immunity last?

Usual suspects: 002 Aedes mosquito

What is dengue? Key facts

Dengue is a virus. It belongs to the flavivirus family, which also includes other vector-borne viruses that cause diseases in humans, such as Zika, yellow fever, and West Nile virus. Infections can be caused by any of the four closely related virus serotypes (DENV-1 to DENV-4).

The dengue virus is transmitted to humans through the bite of mosquitoes—but not just any mosquito. It must be an infected female of the Aedes aegypti or Aedes albopictus species. Both species are highly prolific and well adapted to living in close association with humans. The only continent where these mosquitoes are not found—yet—is Antarctica. Ae. aegypti is more common in tropical and subtropical regions, while Ae. albopictus (also known as the tiger mosquito) can also be found at higher latitudes, such as Europe, the U.S., and Japan.

How long does dengue last? Stages of the illness

Dengue usually lasts between 2 and 7 days. About 1 in 20 people with the disease may develop severe dengue, which can be fatal if not treated promptly. Between 2% and 5% of people with severe dengue may die. Without treatment, mortality from severe dengue can reach 50%.

People previously infected with one serotype develop immunity to that serotype but are more likely to develop severe dengue if they are later infected with a different serotype, because existing antibodies help the virus enter cells (a phenomenon known as antibody-dependent enhancement or ADE). Infants and pregnant women are also at greater risk of severe dengue.

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Dengue symptoms: how to identify it early

The most common symptoms are fever, rash, pain (including pain behind the eyes), and intense joint pain. However, not everyone develops symptoms.

Symptoms of severe dengue include bleeding from the nose or gums, vomiting, breathing difficulty, low blood pressure, and organ failure.

How is dengue diagnosed?

Dengue is usually diagnosed in a laboratory using molecular tests (to amplify viral DNA) or serological tests (to detect antibodies against the virus). Rapid tests are available, but their sensitivity varies depending on the serotype and whether it is the first infection or there have been previous ones.

How is dengue treated? Care and treatment

There is still no specific treatment for dengue, although promising results have recently been announced for an antiviral pill tested in a very small human trial.

Currently, two dengue vaccines are authorized. The first one (Dengvaxia, by Sanofi) is only recommended for people living in endemic areas who have already had a previous infection. The second one, by Takeda, was approved by the European Medicines Agency (EMA) for use in people over 4 years old in endemic areas and travelers, regardless of prior infection. This vaccine was also recently recommended by a World Health Organization (WHO) expert group for children aged 6 to 16 years living in high-transmission areas.

Recently, very promising phase 3 results were published for another tetravalent vaccine developed by Brazil’s Butantan Institute. The vaccine, based on live-attenuated virus, was shown to be safe and highly effective in preventing symptomatic dengue in both children and adults, regardless of prior infection.

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Dengue epidemic: causes and prevention

Global warming, combined with high international mobility, means that mosquito-borne diseases like dengue, malaria, and chikungunya—once confined to the tropics—are now spreading worldwide. In the U.S., 516 locally acquired dengue cases have been reported so far in 2023. Southern Europe is particularly vulnerable, with 10 local outbreaks and over 100 reported cases (although this number is likely higher, as around 50% of infections are asymptomatic). Spain, which eliminated yellow fever and dengue from its port cities over 50 years ago, now faces a renewed risk of sustained local transmission due to the spread of mosquito vectors and increased arrival of infected travelers. In France alone, cases could surpass 3,000 per year by 2030 (up from 65 in 2022) if temperatures continue to rise at the current rate, according to a recent analysis.

What can we do? As the number and global spread of dengue cases increase, vector control and community awareness and action are crucial to reduce disease transmission. Some novel vector control strategies, such as releasing mosquitoes infected with Wolbachia (a bacterium that protects them from virus infection), are showing very promising results in endemic areas. Developing more sensitive rapid diagnostic tests, specific treatments, and effective vaccines, and especially ensuring they are affordable and accessible to those who need them, will also be key to reducing the health impact of a disease that now threatens half of the world’s population. Needless to say, reducing the impact not only of dengue but also of other emerging and re-emerging diseases, and many other health threats, ultimately depends on taking meaningful action to reverse climate change and biodiversity loss.

The best preventive measure remains avoiding mosquito bites (especially at dawn and dusk, when Aedes mosquitoes are most active), by using repellents and clothing that covers arms and legs, as well as controlling mosquito populations by regularly emptying water containers where they lay their eggs.

Dengue worldwide: current impact and statistics

Dengue incidence has risen dramatically in recent decades. As of 2023, over 3.7 million cases and more than 2,000 deaths have been reported globally. In Bangladesh, for example, the number of dengue cases and deaths in 2023 (>200,000 and >1,000, respectively) exceeds the total of all previous years since 2000. In Peru, the worst epidemic in over a decade has been recorded, with more than 150,000 cases and 252 deaths in 2023—many among children. This surge in cases is not limited to tropical and subtropical regions, where dengue is more common. It is also happening in places like Europe and the United States, where local transmission was once rare.

[This article was originally published on February 2016 and last updated on April, 2025]