Yellow Fever

What is Yellow Fever?

Yellow Fever is a viral disease. Symptoms of infection appear 3 to 6 days after exposure, these include: sudden onset of fever, headache, chills, nausea, vomiting, and muscle pain, especially backache. Mild cases of infection usually end at the fifth day, others may progress to yellow discoloration of skin and eyes, liver and kidney failure, and internal bleeding. The case-fatality rate is more than 20% .

How does it spread?

Yellow Fever exists in the tropical regions of Central and South America and Sub-Saharam Africa (see map below). It is transmitted by mosquito bites. Humans and mosquitoes are the reservoirs in urban areas. In the forests other vertebrates and forest mosquitoes are the reservoirs. There is no evidence that Yellow Fever has been present in Asia.

How can you prevent it?

The first line of defense is to protect against mosquito bites. Travellers should wear long-sleeved shirts and trousers, rest in air-conditioned or well-screened rooms and use insect repellents containing DEET (for children keep DEET concentration below 20%) on exposed skin. If travelling in endemic rural areas, carry a portable bed-net and apply permethrin on it as well as to clothes.

The second line of defense is vaccination. There is a very good vaccine available. The Yellow Fever vaccine is an attenuated, live-virus vaccine. It is given as a single injection, administered at least 10 days before travelling and is valid for 10 years with almost total efficacy.

Many countries require a valid International Certificate of Vaccination against Yellow Fever from travellers arriving from Yellow Fever endemic country, or who have been in transit through those areas. For those who are contraindicated for vaccination, they should obtain a letter of exemption from the medical practitioner and seek advice from the relevant embassy before travel.

How is it treated?

If symptoms of infection occurred, one should consult medical advice early. Once confirmed to be infected, the person will be isolated and measures of preventing the access of mosquitoes will be implemented. Treatment will be hospital based and only supportive treatment is available at the moment.

[Yellow Fever, 2008]


Last revision date: 10 October 2012