Dengue

A viral infection spread by Aedes mosquitoes, endemic in tropical and subtropical regions and expanding with climate change and urbanisation.

How it spreads

Bites of day-biting Aedes mosquitoes; not spread directly from person to person.

Common symptoms

High fever, severe headache, pain behind the eyes, muscle and joint pain, nausea and rash; most recover in 1–2 weeks.

When to seek care

The 24–48 hours after the fever drops is the danger window: severe abdominal pain, persistent vomiting, bleeding gums or nose, blood in vomit or stool, rapid breathing, extreme fatigue or restlessness — seek urgent care. Avoid aspirin and NSAIDs (bleeding risk; especially important for kidney patients).

Prevention & treatment

Mosquito-bite prevention (clothing, repellents, screens, nets) and removing standing water; dengue vaccines are approved in some countries for limited groups — follow local guidance.

Unknowns & ongoing research

A second infection with a different serotype carries higher risk of severe dengue; mechanisms are still being studied, and long-term vaccine protection and target groups are under evaluation.

Related WHO notices

WHO Disease Outbreak News · Last successful update on this site: 2026-11-12 01:10 UTC

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Official sources & interactive data