Dengue is a viral infection caused by the Dengue virus (DENV), transmitted to humans through the bite of infected mosquitoes. There is no direct human-to-human transmission, although humans are the primary host of the virus. The virus circulates in the blood of an infected person for 2-7 days, during which time mosquitoes can pick it up and transmit it to other individuals. In the Western Hemisphere, the primary vector is the Aedes aegypti mosquito; however, cases of transmission by Aedes albopictus have been reported. Dengue has been known for over two centuries and is particularly prevalent during and after the rainy season in tropical and subtropical areas of Africa, Southeast Asia and China, India, the Middle East, Latin and Central America, Australia, and several parts of the Pacific.
In recent decades, the spread of dengue has grown in many tropical regions. In northern hemisphere countries, particularly in Europe, it poses a danger from a global health perspective, as it manifests itself mainly as an imported disease, the rising incidence of which is due to the increased movement of goods and people. According to the WHO, the incidence of dengue has increased 30-fold in the last 50 years. It is estimated that up to 50-100 million infections occur annually in more than 100 endemic countries, putting almost half of the world’s population at risk.
Epidemiological Surveillance (30/03/2026 update)
Based on epidemiological updates provided by the European Centre for Disease Control and Prevention (ECDC), through the Multi-country (World) Monitoring of Global Outbreaks, the following is reported:
Global Update
Overall, 78 countries/territories reported dengue cases between January and March 2026.
https://www.ecdc.europa.eu/en/dengue-monthly
Americas
In the Americas Region, as of February 15, 2026, 299,210 cases of DENV have been reported, 22% of which were laboratory-confirmed. According to the WHO/PAHO report, released on March 16, 2026, the current number of reported cases is 64% lower than the same period in 2025 and 57% lower than the five-year average. Although all four serotypes have been reported in the Americas Region, their distribution varies across PAHO countries.
Southeast Asia
According to WHO SEARO epidemiological bulletins, Sri Lanka, India, Thailand, Bangladesh, Timor-Leste, and Nepal reported cases of dengue in February 2026.
- Sri Lanka, Bangladesh, India, and Thailand have reported comparable numbers of cases to previous years. Sri Lanka has reported 13,760 cases as of March 1, 2026, with a slight decrease in the week of February 23 to March 1 (1,265 cases) compared to the week of February 16 to 22 (1,487 cases). Bangladesh has reported 1,870 cases in 2026 (as of March 8). India has reported 6,563 cases, and Thailand has reported 3,191 cases in 2026 (as of February 28).
- In East Timor, the upward trend recorded in January 2026, with 1,281 cases, was also observed in February 2026 (2,105 cases). This represents a tenfold increase compared to the number of cases reported in February 2025.
- Maldives continued to report an increasing number of cases in January 2026 (646 cases), following trends observed since late 2025 (411 cases reported in December and 382 cases reported in November 2025).
Western Pacific Region
In the WHO Western Pacific Region, dengue cases were reported from several countries in the reports dated 5 and 19 March 2026 (WPRO Dengue Situation Update No. 741: 5 March 2026, WPRO Dengue Situation Update No. 742: 19 March 2026). The following trends were highlighted by country:
- Cambodia: A downward trend and weekly fluctuations were observed until early March, with 254 cases reported in the week of March 2–8, 2026. Since the beginning of 2026, 4,338 cases have been reported, compared to 1,392 cases reported in the same period in 2025.
- China: 94 cases were reported in February 2026, and 93 cases in January 2026. Although there has been a decline in monthly cases since December 2025, when 151 cases were reported, the cases reported in January 2026 are 84.3% higher than those reported in January 2025.
- Indonesia: The downward trend that began in October 2025 continued in 2026, with 4,383 cases reported in January 2026 and 2,489 cases reported in February 2026.
- Laos: Weekly fluctuations in the number of cases are observed (39 cases in the week of February 16–22, 33 in the week of February 23–March 1, and 39 in the week of March 2–8). The 703 cases reported in 2026, as of March 8, represent a 56.9% increase compared to the same period in 2025.
- Malaysia: 1,116 cases were reported in the week of March 1-7, and a total of 11,340 cases in 2026, with similar trends to those reported in 2025.
- Singapore: i casi rimangono a livelli inferiori rispetto agli anni precedenti, con 43 casi segnalati nella settimana dall’1 al 7 marzo. Complessivamente, al 7 marzo 2026 sono stati segnalati 322 casi.
- Vietnam: 1,856 cases were reported between February 28 and March 6, and 27,365 cases since the beginning of 2026. The decreasing trend recorded in February continues, but overall there has been a doubling compared to 2025. Most cases in 2026 were reported in the Southern Region (86.6%).
Africa
According to the Africa CDC Epidemiological Intelligence Report released on March 23, 2026, a total of 658 cases have been reported in the region as of March 20, 2026, including 589 in Mali, 33 in Mauritania, 35 in Senegal, and 1 in the Central African Republic.
EU/EEA
No cases have been reported in the EU/EEA, excluding the outermost regions, where cases have been reported in Martinique, Guadeloupe, Réunion, and French Guiana, and an increase in consultations in Mayotte.
In Martinique, dengue transmission continues at high levels with weekly fluctuations. Twenty-nine confirmed cases were reported in the week from 15 to 21 February and 53 confirmed cases in the week from 22 to 28 February, according to the Dengue Surveillance Report published on 6 March 2026.In Guadeloupe, according to the same report, dengue has been circulating at low levels since mid-January. In Saint Martin, no cases have been reported since mid-January 2026 (Dengue aux Antilles, Bulletin of 6 March 2026).
In Réunion, since the beginning of 2026, 24 dengue cases have been reported up to 1 March 2026, of which ten were reported between 9 and 15 March 2026, and others.
The likelihood of further transmission of the dengue virus in continental Europe is linked to the importation of the virus by viremic travelers into host areas with stable and active competent vectors (e.g., Aedes albopictus and Aedes aegypti). Aedes albopictus is present throughout much of Europe. In Europe and adjacent areas, Aedes aegypti is present in Cyprus, the eastern Black Sea coast, and the remotest region of Madeira.
In light of the above, with respect to the non-European areas with active circulation reported by ECDC, it is recommended to:
- to strengthen surveillance measures for potential imported cases by implementing donor medical history screening for travel to areas at risk;
- to apply a 28-day temporary deferral criterion from the date of return for donors who have stayed in the affected areas, or alternatively to perform NAT testing;
- to apply a 120-day temporary deferral criterion from the resolution of symptoms for donors with a positive history of DENV infection (either documented infection or the onset of symptoms consistent with DENV infection);
- to raise donors’ awareness of the need to inform their reference transfusion service in the event of the onset of symptoms consistent with DENV infection, or in the event of a confirmed diagnosis of DENV infection within 14 days following donation (post-donation information).
Testing and suspension periods may be waived if the donation is used exclusively for plasma intended for fractionation.
Decrees (Italian Text)
21/02/2024 – Nota Ministero della Salute: Aumento globale dei casi di dengue, predisposizione alla stagione vettoriale 2024
21/07/2023 – Misure di prevenzione Dengue – Dipartimenti di Guadalupa e della Guyana francese, Collettività della Martinica, di Saint-Martin e di Saint Barthèlemy (Francia)
21/02/2024 – Nota Ministero della Salute: Aumento globale dei casi di dengue, predisposizione alla stagione vettoriale 2024
01/10/2024 – Misure di prevenzione Dengue – Réunion (Francia)
06/12/2024 – Aggiornamento globale DENV – ECDC
22/07/2025 – Nota Ministero della Salute – ARBOVIROSI: Prevenzione, sorveglianza ed interventi in risposta alla circolazione delle arbovirosi trasmesse da Aedes spp. – stagione vettoriale 2025
30/04/2026 – Nota Ministero della Salute – ARBOVIROSI: Prevenzione, sorveglianza ed interventi in risposta alla circolazione delle arbovirosi oggetto di sorveglianza del Piano Nazionale di revenzione, sorveglianza e risposta alle Arbovirosi, PNA 2020-2025 – stagione vettoriale 2026.