Yellow fever

Yellow fever is a viral disease caused by yellow fever virus (YFV), and is often found in tropical and subtropical areas of Africa and South America.

Areas of risk

Yellow fever virus is found in tropical and subtropical areas of Africa and South America

Key facts

The "yellow" in the name refers to the jaundice (yellowing of the skin and eyes) seen in some patients.

Yellow fever is transmitted via mosquitoes from monkeys to humans.

prevention guidance

Most patients experience mild or no symptoms; however, 12% of patients with symptoms go on to develop serious life-threatening illness.

Some countries in South America and Africa have certain requirements that need to be met before they will issue the traveller a visa. This is to prevent importing the disease. Be sure to ask about this when you visit a travel health clinic or the next time you speak to a healthcare professional before your trip.

Yellow fever at a glance

Primary vector

Aedes and Haemagogus

Biting habits:

  • Aedes bite primarily during the day, sometimes at night
  • Haemagogus bite during the day


The majority of people infected with YFV will either not have symptoms, or have mild symptoms and completely recover.

Most common:

  • Fever
  • Chills
  • Headache
  • Backache
  • Muscle aches

A few people will develop a more severe form of the disease. Symptoms of serious illness include:

  • High fever
  • Jaundice (yellow skin or eyes)
  • Bleeding
  • Shock
  • Organ failure

Among those who develop severe disease, 30-60% die.

Help reduce the risk of mosquito-borne diseases dampening your travel experience. Learn more by speaking to your healthcare professional, such as a doctor or pharmacist, or visiting a travel clinic, before your next trip.