YELLOW FEVER

What is Yellow Fever?

Yellow fever is caused by a virus that is transmitted to man through the bite of infected mosquitos. The disease varies in duration and severity. The incubation period varies from 3 to 6 days.

Although the disease is often benign, it can also be quite serious. It begins abruptly with fever, headaches, backache, extreme fatigue, nausea and vomiting. Progressively with the evolution of the disease, kidney failure and haemorrhage occurs. Jaundice is moderate at the beginning of the disease, and then progressively severe. Death occurs in 20 to 30 % of cases.

Yellow fever is present only in certain countries of Africa and South America.

Prevention

The vaccine counters yellow fever (antiamarile) is a live attenuated virus vaccine recommended for certain travellers visiting countries where the infection is present. It is obligatory for entry in certain countries.

Principal preventitive measures consist of being vaccinated at least 10 days before visiting zones at risk and wearing protective clothing, insect repellant, and using mosquito nets. The vaccine confers protection in 95% of cases. Boosters are recommended every 10 years, if the risk persists.

Possible Side Effects and Countermeasures

1. In the majority of the cases, the vaccine does not cause any reaction.

2. Less than 5% of the vaccinated people will present, 5 to 10 days after vaccination, a fever accompanied by headaches and muscular pains, of 1 to 3 days' duration. It is advised to rest , to hydrate well and use an anti-fever medication (if fever > 38,5C oral or 39,0C rectal) such as acetaminophen.

3. A severe allergic reaction following vaccination against yellow fever is extremely rare and occurs particularly in people allergic to eggs (less than 1 case in 1,000,000).

4. Very seldom the vaccine has caused a cerebral complication, encephalitis, in young children. In the United States, 2 cases of encephalitis were announced after the administration of 34 million vaccines.

5. In the presence of significant reactions following vaccination, consult a doctor and to let us know. Mention at the time of subsequent boosters any reaction which has occurred during preceding vaccination.