Key information
- Dengue is a viral an infection attributable to the dengue virus (DENV), which is transmitted to people by the chew of contaminated mosquitoes.
- About half of the world’s inhabitants is now vulnerable to dengue, with an estimated 100–400 million infections occurring every year.
- Dengue is present in tropical and sub-tropical climates worldwide, largely in city and semi-urban areas.
- Whereas many DENV infections are asymptomatic or produce solely delicate sickness, DENV can often trigger extra extreme circumstances, and even loss of life.
- Prevention and management of dengue depend on vector management. There is no such thing as a particular therapy for dengue/extreme dengue, and early detection and entry to correct medical care vastly decrease fatality charges of extreme dengue.
Overview
Dengue (break-bone fever) is a viral an infection that’s unfold from mosquitoes to folks. It’s extra frequent in tropical and subtropical than in temperate climates.
Most individuals who get dengue do not need signs. For many who do, the commonest signs are excessive fever, headache, physique aches, nausea and rash. Most get higher in 1–2 weeks. Some develop extreme dengue and want care in a hospital.
In extreme circumstances, dengue might be deadly.
You possibly can decrease your threat of dengue by avoiding mosquito bites, particularly through the day.
Dengue is handled by ache administration as there is no such thing as a particular therapy presently.
Signs
Most individuals with dengue have delicate or no signs and can get higher in 1–2 weeks. Not often, dengue might be extreme and result in loss of life.
If signs happen, they normally start 4–10 days after an infection and final for two–7 days. Signs might embrace:
- excessive fever (40°C/104°F)
- extreme headache
- ache behind the eyes
- muscle and joint pains
- nausea
- vomiting
- swollen glands
- rash.
People who’re contaminated for the second time are at larger threat of extreme dengue. The signs of extreme dengue usually come after the fever has gone away and will embrace:
- extreme stomach ache
- persistent vomiting
- speedy respiratory
- bleeding gums or nostril
- fatigue
- restlessness
- blood in vomit or stool
- being very thirsty
- pale and chilly pores and skin
- feeling weak.
Individuals with these extreme signs ought to search care instantly.
After restoration, individuals who have had dengue might expertise fatigue for a number of weeks.
Diagnostics and therapy
Laboratory-based and level of care diagnostics are essential to manage and handle dengue, but international disparities in laboratory capabilities current important challenges. The diagnostic algorithms, testing methods and take a look at methodologies employed differ, relying on the capabilities of nationwide laboratory techniques. The big selection of accessible checks – together with nucleic acid amplification checks (NAATs), enzyme-linked immunosorbent assays (ELISAs) and speedy diagnostic checks (RDTs) – differ considerably in high quality and efficiency.
Laboratory testing for arboviruses might be completed by both direct detection strategies resembling virus isolation, molecular detection of nucleic acid or antigen testing, together with speedy diagnostic checks (RDTs) throughout the first week of sickness.
There is no such thing as a particular therapy for dengue, though ache might be managed with remedy resembling paracetamol (acetaminophen). Non-steroidal anti-inflammatory medicines resembling ibuprofen and aspirin must be averted as they will improve the chance of bleeding.
For folks with extreme dengue, hospitalization is commonly vital.
World burden
The incidence of dengue has grown dramatically worldwide in latest a long time, with the variety of circumstances reported to WHO growing from 505 430 circumstances in 2000 to 14.6 million in 2024. The overwhelming majority of circumstances are asymptomatic or delicate and self-managed, and therefore the precise numbers of dengue circumstances are under-reported. The illness is now endemic in additional than 100 nations.
In 2024, extra circumstances of dengue have been recorded than ever earlier than in a 12-month interval, affecting over 100 nations on all continents. Throughout 2024, ongoing transmission, mixed with an surprising spike in dengue circumstances, resulted in a historic excessive of over 14.6 million circumstances and greater than 12 000 dengue-related deaths reported. The Area of the Americas contributed a big proportion of the worldwide burden, with over 13 million circumstances reported to WHO.
A number of elements are related to the growing threat of unfold of the dengue epidemic, together with the altering distribution of the accountable vectors (mainly Aedes aegypti and Aedes albopictus), particularly in beforehand dengue-naive nations; local weather change resulting in growing temperatures, excessive rainfall and humidity; fragile and overburdened well being techniques; limitations in surveillance and reporting; and political and monetary instabilities in nations going through advanced humanitarian crises and excessive inhabitants actions.
One modelling estimate signifies 390 million dengue virus infections per yr, of which 96 million manifest clinically(1).A latest examine on the prevalence of dengue estimates that 5.6 billion individuals are vulnerable to an infection with dengue and different arboviruses(2).
From January to July 2025, over 4 million circumstances and over 3000 deaths have been reported to WHO from 97 nations.
Dengue is spreading to new areas, together with the European and Jap Mediterranean areas. In 2024, 308 circumstances have been reported to WHO from three European nations (France, Italy and Spain) and an extra 1291 circumstances and 4 deaths have been recorded within the French abroad territories of Mayotte and Réunion.
Transmission
Transmission by the mosquito chew
The dengue virus is transmitted to people by the bites of contaminated feminine mosquitoes, primarily the Aedes aegypti mosquito. Different species throughout the Aedes genus may act as vectors, however their contribution is generally secondary to Aedes aegypti.
After feeding on a DENV-infected particular person, the virus replicates within the mosquito midgut earlier than disseminating to secondary tissues, together with the salivary glands. The time it takes from ingesting the virus to precise transmission to a brand new host is termed the extrinsic incubation interval (EIP). The EIP takes about 8–12 days when the ambient temperature is 25–28°C. Variations within the EIP should not solely influenced by ambient temperature but in addition by a number of different elements – such because the magnitude of every day temperature fluctuations, the virus genotype, and the preliminary viral focus – which may additionally alter the time it takes for a mosquito to transmit the virus. As soon as infectious, a mosquito can transmit the virus for the remainder of its life.
Human-to-mosquito transmission
Mosquitoes can change into contaminated by people who find themselves viremic with DENV. This may be somebody who has a symptomatic dengue an infection, somebody who’s but to have a symptomatic an infection (those that are pre-symptomatic), and in addition somebody who reveals no indicators of sickness (those that are asymptomatic).
Human-to-mosquito transmission can happen as much as 2 days earlier than somebody reveals signs of the sickness, and as much as 2 days after the fever has resolved.
The danger of mosquito an infection is positively related to excessive viremia and excessive fever within the affected person; conversely, excessive ranges of DENV-specific antibodies are related to a decreased threat of mosquito an infection. Most individuals are viremic for about 4–5 days, however viremia can final so long as 12 days.
Maternal transmission
The first mode of transmission of the DENV between people entails mosquito vectors. There may be proof, nevertheless, of the potential of maternal transmission (i.e. from a pregnant mom to her child). On the identical time, vertical transmission charges seem low, with the chance of vertical transmission seemingly linked to the timing of buying the dengue an infection throughout being pregnant. When a mom does have a dengue an infection when she is pregnant, infants might endure from pre-term beginning, low birthweight and fetal misery.
Different transmission modes
Uncommon circumstances of transmission through blood merchandise, organ donation and transfusions have been recorded. Equally, transovarial transmission of the virus inside mosquitoes has additionally been recorded.
Threat elements
Earlier an infection with DENV will increase the chance of a person growing extreme dengue.
Urbanization (particularly speedy, unplanned urbanization), is related to dengue transmission by a number of social and environmental elements: inhabitants density, human mobility, entry to dependable water supply, water storage practices, and so forth.
Group dangers to dengue additionally depend upon inhabitants information, attitudes and practices in the direction of dengue, as publicity is intently associated to behaviours resembling water storage, plant-keeping and self-protection towards mosquito bites. Routine vector surveillance and management actions and focused group engagement vastly improve resilience.
Vectors can adapt to new environments and local weather. The interplay between the dengue virus, the host and the surroundings is dynamic. Consequently, illness dangers might change and shift with local weather change in tropical and subtropical areas, together with elevated urbanization and inhabitants motion.
Prevention and management
The mosquitoes that unfold dengue are energetic through the day.
To decrease your threat of getting dengue, shield your self from mosquito bites by utilizing:
- garments that cowl as a lot of your physique as potential;
- mosquito nets, ideally sprayed with insect repellent, if sleeping through the day;
- window screens;
- mosquito repellents (containing DEET, Picaridin or IR3535); and
- coils and vaporizers.
To stop mosquitoes from breeding:
- implement environmental administration and modification practices to cease mosquitoes from accessing egg-laying habitats;
- get rid of stable waste correctly and take away synthetic habitats that may maintain water;
- cowl, empty and clear home water storage containers on a weekly foundation; and
- apply applicable pesticides to water storage out of doors containers.
If you happen to get dengue, it’s vital to:
- relaxation;
- drink loads of liquids;
- use acetaminophen (paracetamol) for ache;
- keep away from non-steroidal anti-inflammatory remedy resembling ibuprofen and aspirin; and
- look ahead to extreme signs and speak to your physician as quickly as potential should you discover any.
At the moment, one vaccine (QDenga) is accessible and licensed in some nations. Nonetheless, it is suggested just for these aged 6–16 years in excessive transmission settings. A number of further vaccines are below analysis.
WHO response
WHO responds to dengue by:
- supporting nations within the affirmation of outbreaks by its collaborating community of laboratories;
- offering technical recommendation and steering to nations for the efficient administration of dengue outbreaks;
- supporting nations to enhance their reporting techniques and seize the true burden of the illness;
- offering coaching on medical administration, prognosis and vector management on the nation and regional ranges in collaboration with its collaborating centres;
- formulating evidence-based methods and insurance policies;
- supporting nations to develop dengue prevention and management methods and undertake the World Vector Management Response (2017–2030) and the World Arbovirus Initiative (2022–2025);
- reviewing and making suggestions on the event of latest instruments, together with insecticide merchandise and utility applied sciences;
- gathering official data of dengue and extreme dengue from over 100 Member States; and
- publishing steering and handbooks for surveillance, case administration, prognosis, dengue prevention and management for Member States.
References
- Bhatt S, Gething PW, Brady OJ, Messina JP, Farlow AW, Moyes CL, et al. The global distribution and burden of dengue. Nature. 2013;496(7446):504–507. doi: 10.1038/nature12060
- Lim A, Shearer FM, Sewalk K, Pigott DM, Clarke J, Ghouse A, et al. The overlapping global distribution of dengue, chikungunya, Zika and yellow fever. Nat Commun. 2025;16(1):3418. doi: 10.1038/s41467-025-58609-5.
