Dengue
Dengue is an infection caused by the dengue virus of which there are four different types (serogroups) DENV-1, DENV-2, DENV-3 and DENV-4. The disease is spread through the bite of an infected mosquito. The mosquitoes that spread dengue usually breed in urban areas close to human habitation and are most active during daylight hours. Although unpleasant, dengue is usually a self-limiting illness. However, a small, but significant, number of people can develop more life-threatening infection (severe dengue).
The disease is common in the tropics. Affected areas include the Caribbean, South and Central America, Africa, Asia and the Pacific Islands. Although less common, outbreaks are increasingly being reported outside tropical areas, including in Europe, with locally acquired cases reported in Croatia, France, Italy, Madeira and Spain.
Dengue does not occur naturally in the United Kingdom (UK) but is reported in travellers returning from dengue affected areas. Cases of dengue in UK travellers are increasing, with most reported in travellers who visited Asia, Central and South America or the Caribbean. Country-specific information on dengue is available on our Country Information pages and current dengue outbreaks are listed on our Outbreak Surveillance section.
All travellers to dengue endemic countries are at risk of dengue infection. The chance of becoming infected with dengue is determined by several factors, including destination, length of exposure and season of travel. Risk is thought to be higher during periods of intense mosquito feeding activity (two to three hours after dawn and during the early evening). Travellers, who spend long periods in areas where dengue is common, are at increased risk, but even short-term visitors can be infected.
Approximately 40 to 80 percent of people infected with dengue remain symptom-free. If symptoms do occur, the illness usually begins abruptly with a high fever, and is often accompanied by a severe headache, muscle and joint pain, nausea, vomiting and a rash. Most infections are self-limiting, with a rapid recovery three to four days after the rash appears.
A small number of people develop more severe illness with symptoms which can include dangerously low blood pressure (shock), fluid build-up in the lungs and severe bleeding. There is no specific drug treatment for severe dengue illness, although hospital admission and careful management of fever, fluid balance and pain can help with recovery. If left untreated, severe dengue illness can be fatal. With good medical care, death due to severe dengue is typically less than one percent.
Prevention
Travellers can check our Country Information pages for information on the risk of dengue at their destination. Mosquito bite avoidance is recommended. As dengue is spread by day-biting mosquitoes, particular care with bite avoidance is advised during the day, especially around dawn and dusk.
A vaccine, Qdenga®▼ has been licensed in the UK for the prevention of dengue disease in individuals from 4 years of age.
The UK Joint Committee on Vaccination and Immunisation (JCVI) has advised that Qdenga®▼ vaccine can be considered for individuals aged 4 years of age and older who have a confirmed or likely history of dengue infection in the past and are:
- planning to travel to dengue where there is a risk of dengue infection or areas with an ongoing outbreak of dengue
or
- exposed to dengue virus through their work, for example, laboratory staff working with the virus.
Vaccination can be considered in those who have not had dengue in the past. In these situations, discussion with a travel health clinician experienced in assessing the balance of potential risks and benefits of Qdenga®▼ is recommended.
Blood tests for previous dengue infection may not be 100 percent reliable and assessment must be made of previous tests for dengue, likely exposure and clinical history. In the UK, tests for previous dengue infection are usually offered privately, (a fee is charged to the individual being tested). Guidance on investigating previous dengue infection and use of Qdenga®▼ is available in the UKHSA 'green book' Immunisation against infectious disease, dengue chapter.
Qdenga®▼ is a live vaccine (it contains live, attenuated dengue virus) and cannot be given to travellers who are immunosuppressed (have a weakened immune system), pregnant or breastfeeding. This vaccine is also contraindicated (cannot be given) for those with hypersensitivity to any component of the vaccine and for children under four years of age.
Resources
- More detailed information on can be found in our dengue factsheet
- UKHSA: Dengue: guidance, data and analysis
- UKHSA: Dengue chapter 'green book' Immunisation against infectious disease
- Joint Committee on Vaccination and Immunisation (JCVI): Minutes of meeting February 2026
- World Health Organization (WHO): Fact sheets: dengue
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Recent News on Dengue
Updated dengue 'green book' chapter published
The dengue chapter of the 'green book' (Immunisation against infectious disease) has been updated
Updated: 17 September 2026Worldwide dengue risk reminder
Dengue is a mosquito-spread virus found in tropical and subtropical world regions, including parts of mainland Europe
Updated: 11 June 2026Changes to the Country Information pages: dengue vaccine recommendations
NaTHNaC has reviewed and updated the dengue country-specific information and vaccine recommendations
Updated: 02 May 2025Mosquito and insect spread infections in the Caribbean
An increase in cases of mosquito and insect spread infections have been reported in the Caribbean region
Updated: 24 December 2024Recent Dengue Outbreaks
Dengue in Nigeria
As of October 2026, a total of 523 suspected dengue fever cases (34 confirmed and four deaths) have been reported in Nigeria for 2026. 220 suspected cases have been reported in October 2026 alone across Akwa-Ibom, Sokoto and Zamfara States. Please see our Topics in Brief article for further details on dengue.
As of June 2026, a total of 95 (nine confirmed) dengue cases have been reported in Nigeria for 2026. Please see our Topics in Brief article for further details on dengue.
Source: StateHealth authorities in Nigeria state that a total of 735 (219 confirmed) dengue cases, with two deaths, were reported between January and November 2025. Most cases were reported in Edo (537 cases) and Sokoto (96 cases) states. Please see our Topics in Brief article for more details on dengue.
Source: StateDengue in Italy
As of 3 November 2026, the Italian authorities confirmed 76 locally acquired dengue cases reported for 2026 traced to five distinct outbreaks and two sporadic cases in Rome (Lazio) currently being investigated. The largest outbreaks were reported in Livorno and Florence Provinces (Tuscany) with 40 confirmed cases. Other affected provinces include Lecce (Puglia), Milan (Lombardy), Vicenza (Veneto) and Naples (Campania). Please see our Topics in Brief article for further details on dengue.
As of 8 October 2026, the Italian authorities confirmed the 68 locally acquired dengue cases reported for 2026 were in the following regions: Campania (2), Lazio (1), Lombardy (2), Puglia (20), Tuscany (36) and Veneto (7). Please see our Topics in Brief article for further details on dengue.
Source: StateAs of 7 October 2026, a total of 68 confirmed locally acquired dengue cases have been reported for 2026 in Italy. Please see our Topics in Brief article for further details on dengue.
Source: ECDCAs of 29 September 2026, a total of 59 confirmed locally acquired dengue cases have been reported for 2026 in Italy. Please see our Topics in Brief article for further details on dengue.
Source: StateAs of 22 September 2026, a total of 47 confirmed locally acquired dengue cases have been reported for 2026 in Italy. The cases have been reported in Puglia (13), Tuscany (31), Lombardy (2), Campania (1) regions of Italy. Please see our Topics in Brief article for further details on dengue.
Source: StateAs of 8 September 2026, a total of 24 confirmed locally acquired dengue cases have now been reported for 2026 in the Puglia and Tuscany regions of Italy. Please see our Topics in Brief article for further details on dengue.
Source: StateAs of 30 August 2026, a total of three confirmed locally acquired dengue cases have been reported during 2026 in the Puglia and Tuscany regions of Italy. Please see our Topics in Brief article for further details on dengue.
Source: StateDengue in Peru
As of 17 October 2026, a total of 76,784 dengue cases (59,728 confirmed) and 81 deaths have now been reported in Peru during 2026. Serotypes DENV-1, DENV-2 and DENV-3 have been identified. Please see our Topics in Brief article for further details on dengue.
As of 28 June 2026, 34,820 cases (36 deaths) of dengue have been reported in Peru since the start of the year. A total of 39,211 cases (56 deaths) were reported during the whole of 2025. Serotypes DENV-1, DENV-2 and DENV-3 have been recorded. Please see our Topics in Brief article for further details on dengue.
Source: PAHOAs of 1 Feburary 2026, 4,344 cases (three deaths) of dengue have been reported in Peru since the start of the year. Case numbers usually increase during the first few months of the year. A total of 37,041 cases (56 deaths) were reported during 2025. Serotypes DENV-1, DENV-2 and DENV-3 were reported. Please see our Topics in Brief article for further details on dengue.
Source: PAHOAs of 6 September 2025, a total of 34,990 cases of dengue have been reported since the start of the year. Serotypes DENV1, DENV2 and DENV3 have been recorded in Peru during 2025. Please see our Topics in Brief article for further details on dengue.
Source: PAHOPeru reported 173,706 cases between 1 January 2024 and 26 April 2024, representing an increase of 357% compared to the same period in 2023. The cumulative incidence rate as of 26 April 2024 is 521 cases per 100,000 population.
Source: PAHOAs of 26 June 2023, a total of 172,533 dengue cases, with 228 deaths, have now been reported for 2023. A further 74 deaths are under investigation.
Source: StateFollowing countrywide floods in Peru, the country is experiencing a major dengue outbreak. As of 13 June 2023, a total of 110,000 cases, with more than 176 deaths, have been reported for 2023 (compared to 63,100 cases in 2022). A health emergency has been declared in 222 districts and the government is mobilising resources to scale up health services to assist medical centres coping with large number of daily cases.
Source: ERCCDengue in Colombia
As of 17 October 2026, a total of 91,419 dengue cases (64, 333 confirmed) and 69 deaths have now been reported in Columbia during 2026. Serotypes DENV-1, DENV-2, DENV-3 and DENV-4 have been identified. Please see our Topics in Brief article for further details on dengue.
As of 25 January 2026, 9,383 suspected cases (two deaths) of dengue have been reported in Colombia since the start of the year. Case numbers usually increase during the first few months of the year. A total of 125,119 cases (124 deaths) were reported during 2025. Serotypes DENV-1, DENV-2, DENV-3 and DENV-4 were all reported. Please see our Topics in Brief article for further details on dengue.
Source: PAHOAs of 6 September 2025, a total of 101,523 dengue cases have been reported in Colombia for 2025. Please see our Topics in Brief article for further details on dengue.
Source: PAHOAs of 10 July 2025, a total of 83,083 confirmed dengue cases have been reported in Colombia for 2025. Please see our Topics in Brief article for further details on dengue.
Source: PAHOAs of 10 August 2024, a total of 243,146 cases of dengue have been reported since the beginning of the year. This represents a significant increase in the reporting of dengue cases compared to the last few years. All four dengue serogroups (DENV1-4) are in circulation.
Source: StateColombia reported 112,140 cases of dengue between 1 January 2024 and 26 April 2024, representing an increase of 373% compared to the same period in 2023. The cumulative incidence rate as of 26 April 2024 is 219 cases per 100,000 population.
Source: PAHO
