Dengue

Dengue is a vector-borne viral disease produced by the flavivirus dengue virus (DENV), a positive-stranded enveloped RNA virus of the Flaviviridae family ^[2][3][4]. It is transmitted to humans through the bite of infected Aedes mosquitoes and is caused by four antigenically distinct serotypes, DENV-1 through DENV-4 ^[1][2][3]. The illness is characteristically self-limiting and febrile, with severity ranging from inapparent infection to life-threatening disease ^[1][3].

Infection manifests across a wide spectrum, from asymptomatic or extremely mild presentations to severe illness requiring hospitalization ^[1][2]. Symptoms typically emerge 4–10 days after the bite of an infected mosquito and often resemble influenza, including fever ^[1]. As the condition advances, some patients develop respiratory distress, bleeding from the nose and gums, rapid blood-pressure drop, thrombocytopenia, leucopenia, and increased vascular permeability ^[1][3]. Severe forms include dengue hemorrhagic fever and the potentially fatal dengue shock syndrome ^[2][3].

Dengue occurs in over 100 tropical and subtropical countries, with approximately 400 million infections and around 22,000 deaths each year ^[3][4]. Epidemics display seasonal patterns, frequently peaking during and after rainy periods, and have expanded geographically with increased epidemic activity and cocirculation of multiple serotypes ^[1][5]. Unplanned urbanization and climatic factors such as heat waves have intensified and widened the distribution of the disease in recent years ^[1]. In 1998 it was already the most important tropical infectious disease after malaria, with an estimated 100 million dengue fever cases and 25,000 deaths annually ^[5].

The dengue virus is principally spread by bites of infected female Aedes mosquitoes, which serve as the main vector ^[2][3]. Environmental conditions including high mosquito abundance, rainfall, humidity, and favorable temperatures influence vector reproduction, feeding, and viral incubation ^[1]. Humans acquire infection after being bitten by a mosquito carrying any of the four DENV serotypes ^[1][2][3].

No universally approved prophylactic vaccine or specific antiviral treatment exists, so measures emphasize early diagnosis, public awareness, and proper medical care to lower mortality ^[2][4]. The first licensed tetravalent vaccine (CYD Denvaxia) is not approved in all countries, and vaccine development is hindered by inadequate animal models and antibody-dependent enhancement ^[3][4]. Sustainable vector control and integrated programmatic approaches are needed, as lack of sustained surveillance and control staffing remain major challenges ^[1][5].

1. 1 World Health Organization. Dengue and severe dengue [Internet]. cited 23 Oct 2026. Available from: https://www.who.int/health-topics/dengue-and-severe-dengue
2. 2 Sinha S et al. Dengue virus pathogenesis and host molecular machineries. J Biomed Sci. 2024 Apr 22. PMID: 38649998. doi: 10.1186/s12929-024-01030-9. PubMed: https://pubmed.ncbi.nlm.nih.gov/38649998/
3. 3 Roy SK et al. Dengue virus: epidemiology, biology, and disease aetiology. Can J Microbiol. 2021 Oct. PMID: 34171205. doi: 10.1139/cjm-2020-0572. PubMed: https://pubmed.ncbi.nlm.nih.gov/34171205/
4. 4 Pourzangiabadi M et al. Dengue virus: Etiology, epidemiology, pathobiology, and developments in diagnosis and control - A comprehensive review. Infect Genet Evol. 2025 Jan. PMID: 39732271. doi: 10.1016/j.meegid.2024.105710. PubMed: https://pubmed.ncbi.nlm.nih.gov/39732271/
5. 5 Gubler DJ et al. Dengue and dengue hemorrhagic fever. Clin Microbiol Rev. 1998 Jul. PMID: 9665979. doi: 10.1128/CMR.11.3.480. PubMed: https://pubmed.ncbi.nlm.nih.gov/9665979/