Yellow Fever

Yellow fever is a disease caused by a virus that is mainly found in tropical areas of Africa, Central and South America.

Transmission

This disease is transmitted through the bite of a mosquito. This mosquito bites at any time of the day, particularly when the sun rises and sets.

Symptoms

Oftentimes, those who contract yellow fever do not have any symptoms. If symptoms develop, they can take 3 to 6 days to appear and can take many forms:

Symptoms tend to disappear after 3 to 4 days and the person recovers. In rare instances, however, it progresses into a more severe form of the disease. This second phase is characterized by severe symptoms, including:

• High fever
• Shock
• Internal bleeding
• Jaundice (yellowing of the skin and whites of the eyes)
• Organ failure, including liver and kidney failure

This severe form of yellow fever can be deadly.

Prevention

Vaccination is recommended for all travellers going to areas where yellow fever is present. The vaccine provides effective immunity within 10 days of being vaccinated. The use of a booster dose is generally not necessary, except for certain groups at increased-risk.

People who receive this vaccine do not usually experience any side effects. However, individuals who are vaccinated can experience weakness, discomfort and headache.

Many nations require yellow fever vaccination as a measure to prevent the introduction of the disease in their country.

In addition to vaccination, certain measures should be taken during your stay to avoid being bitten by mosquitos. For example:

• Wear light-coloured, long-sleeved clothing made of tightly woven materials (e.g., nylon, polyester)
• Wear boots or closed-toe shoes
• Wear a hat
• Wear clothing and use equipment that has been treated with mosquito repellent (permethrin)
• Apply a lotion form of insect repellent that contains DEET or icaridin
• If mosquitos can get into the room, use a permethrin-treated mosquito netting over the bed and secure by tucking under the mattress
  • Avoid touching the netting when in bed as the mosquitos can bite through the net
• Protect children by covering playpens and strollers with mosquito netting
• If possible, use air conditioning
• Opt for accommodations where there are screens on the windows and doors

Treatment

There is no cure for yellow fever. Treatment involves rest, drinking plenty of fluids and using pain relievers to reduce fever and aches.

In the week following your return from a trip, monitor yourself closely for any signs or symptoms that could indicate yellow fever virus infection.

When should I see a healthcare professional?

If you get sick after you return from a trip or if you were sick while you were away, see a healthcare provider upon your return. Medical attention may be required.

For more information:

• Public Health Agency of Canada - Travel Health