Dengue

Mosquito photo. Free public domain CC0 image.

What is Dengue?

Dengue is a globally significant mosquito-borne viral infection caused by four closely related serotypes (DENV-1 to DENV-4). While more than half of the global population is at risk, mainly in tropical and subtropical regions, the disease burden remains high, with about 390 million infections annually but comparatively fewer deaths (up to 36,000).

How is Dengue Spread?

Aedes aegypti plays a central role in dengue transmission, with its habitat closely linked to human environments. Unlike many vectors, it thrives in and around homes by breeding in small, stagnant water containers, increasing human–mosquito contact. Transmission occurs in a cyclical pattern: the mosquito acquires the virus from an infected individual and subsequently spreads it through later bites. This close association between vector ecology and domestic settings makes dengue control highly dependent on household-level prevention strategies. (Source: WMP)

Symptoms of Dengue

Dengue typically presents as a self-limiting illness, with most individuals experiencing mild or no symptoms and recovering within 1–2 weeks. Symptomatic cases usually begin 4–10 days after infection and last 2–7 days. However, secondary infections increase the risk of progression to severe dengue, which can be life-threatening.

Common symptoms:

High fever (up to 40°C)
Severe headache
Pain behind the eyes
Muscle and joint pain
Nausea and/or vomiting
Swollen glands
Skin rash (blotchy, flat or slightly raised, often widespread)

Warning signs of severe dengue (often after fever subsides):

Severe abdominal pain
Persistent vomiting
Rapid breathing
Bleeding (gums or nose)
Fatigue and restlessness
Blood in vomit or stool
Intense thirst
Pale, cold skin
General weakness

Overall, while dengue is often mild, the transition to severe disease—particularly in repeat infections—requires prompt clinical attention to prevent fatal outcomes.

Diagnostics and Treatment of Dengue

Methods such as NAATs, ELISAs, and rapid diagnostic tests differ in availability, quality, and performance across settings. As there is no specific antiviral treatment, care is primarily supportive, with paracetamol recommended for symptom relief, while NSAIDs like ibuprofen and aspirin are avoided due to bleeding risks.

Recent Updates

Dengue has shown a marked global increase in incidence over recent decades, with reported cases rising from 505,430 in 2000 to 14.6 million in 2024, reflecting its expanding public health impact (WHO). More recently, transmission remains widespread, as 78 countries/territories reported cases between January and March 2026, indicating continued global circulation (ECDC).

However, early 2026 data suggest a relative decline compared to the previous year, with over 500,000 cases and more than 100 deaths reported globally as of 23 March 2026—lower than the same period in 2025 (Communicable disease threats report, 22–28 March 2025, week 13). Overall, while long-term trends show significant growth, short-term data indicate possible fluctuations in transmission intensity.