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Dengue

What Should I Do?

Based on CDC and WHO guidance, checked against those sources on Oct 12, 2026. Educational information only — not a diagnosis or a substitute for a licensed healthcare professional.

What it is

Dengue is a viral infection spread by mosquitoes, common in tropical and subtropical regions. About 1 in 4 infections causes illness. Most people recover in about a week, but dengue can become severe and life-threatening.

How it spreads

  • Bites from infected Aedes mosquitoes, which can bite during the day and at night; risk is highest in the early morning and late afternoon.
  • Rarely, from a pregnant person to their baby, or through blood transfusion or organ transplant. There is some evidence it can spread through sex.
  • It does not spread through everyday, casual contact.

Symptoms usually begin 5–7 days after the mosquito bite (range about 3–10 days) and last 2–7 days.

Latest official reports

CDC Travel Health NoticeLevel 1 – Practice Usual PrecautionsDengue

Level 1 - Global Dengue

Where: Global · 15 countries, including Colombia and Vietnam

Excerpt from U.S. CDC Travelers' Health:Dengue is a year-round risk in many parts of the world, with outbreaks commonly occurring every 2–5 years. Travelers to risk areas should prevent mosquito bites.

Published Oct 2, 2026 · U.S. CDC Travelers' HealthShare card
WHO Disease Outbreak NewsDengue

Dengue – Iran (Islamic Republic of)

Where: Country report · Islamic Republic of Iran

Excerpt from World Health Organization:On 14 June 2024, the Ministry of Health and Medical Education (MoHME) of Iran reported the first two locally acquired cases of dengue recorded in the country. Local transmission of dengue within the community was confirmed in Bandar-Lengheh, Hormozgan Province, southern Iran. As of 17 July 2024, the total number of locally acquired (autochthonous) dengue cases in the country has risen to 12, all reported in Bandar-Lengheh. Dengue is a mosquito-borne viral disease caused by the dengue virus, with the potential to cause a serious public health impact. The primary vectors that transmit the diseas

Published Jul 22, 2024 · World Health Organization — Disease Outbreak NewsShare card

Current situation

  • Level 1 - Global Dengue (15 destinations)CDC Travelers' Health · Oct 2, 2026
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Emergency warning signs

  • Belly pain or tenderness
  • Vomiting at least 3 times in 24 hours
  • Bleeding from the nose or gums
  • Vomiting blood, or blood in the stool
  • Feeling very tired, restless or irritable
  • Cold or clammy skin, or difficulty breathing
  • Severe dengue can develop within a few hours and is a medical emergency — don't wait.

Call 911 (U.S.) or your local emergency number.

Dengue · OutbreakWatch