ArabicChineseEnglishFrenchRussianSpanish
WHO home
All WHO This site only
  WHO > Health topics > Yellow fever

Yellow fever

 A young girl waiting in line for yellow fever vaccination in Togo

Yellow fever is a viral disease, found in tropical regions of Africa and the Americas. It principally affects humans and monkeys, and is transmitted via the bite of Aedes mosquitoes. It can produce devastating outbreaks, which can be prevented and controlled by mass vaccination campaigns.

The first symptoms of the disease usually appear 3–6 days after infection. The first, or “acute”, phase is characterized by fever, muscle pain, headache, shivers, loss of appetite, nausea and vomiting. After 3–4 days, most patients improve and symptoms disappear. However, in a few cases, the disease enters a “toxic” phase: fever reappears, and the patient develops jaundice and sometimes bleeding, with blood appearing in the vomit (the typical "vomito negro"). About 50% of patients who enter the toxic phase die within 10–14 days.

There is no specific treatment for yellow fever. Vaccination is highly recommended as a preventive measure for travellers to, and people living in, endemic countries.


GENERAL INFORMATION

Fact sheet on yellow fever

Q&A: What is being done about yellow fever?

MULTIMEDIA

Photo story: Mali – 6 million vaccinated against yellow fever


Photo story: Togo – yellow fever vaccination campaign

WHO PROGRAMMES AND ACTIVITIES

Department of Global Alert and Response

Department of Immunization, Vaccines and Biologicals

YELLOW FEVER IN WHO REGIONS

Region of the Americas–PAHO

African Region

TECHNICAL INFORMATION

Yellow fever

Yellow fever vaccine safety

YELLOW FEVER OUTBREAKS

Yellow fever outbreak news

PUBLICATIONS

Investigation of yellow fever outbreaks in Africa [pdf 2.72Mb]

- More publications on yellow fever

STATISTICS

Immunization surveillance, assessment and monitoring

RELATED TOPICS

Infectious diseases

Vaccines

International Health Regulations


KEY WHO INFORMATION

Director-General
Director-General and senior management

Governance of WHO
WHO Constitution, Executive Board and World Health Assembly

Media centre
News, events, fact sheets, multimedia and contacts

International travel and health
Publication on travel risks, precautions and vaccination requirements

World Health Report
Annual report on global public health and key statistics