Yellow Fever

Disease risk areas
Countries currently reporting human cases to W.H.O.( Weekly Epidemiological record 1999/74/4. 29 January 1999)
IN AFRICA Angola, Benin, Burkina Faso, Cameroon, Democratic Republic of the Congo, Gabon, Gambia, Ghana, Guinea, Liberia, Nigeria, Sierra Leone, Sudan.
IN AMERICA Boliva, Brazil, Colombia, Ecuador, French Guyane, Peru, Venezuela.
Countries where yellow fever occurs in the monkey host - See 'Yellow Fever Infected Zones'

Transmission
Through mosquito bites from infected monkeys or occasionally humans.

Recommendations for travellers
Vaccination is normally recommended for travel to areas where yellow fever is present in the monkey host.
Many of these countries require certificates of vaccination before entry. Some other countries require certificates from those arriving from "infected areas" because they have the mosquito vector and have the potential to become "infected". For country specific advice see the country concerned.

Vaccination

Always confirm details with manufacturer's literature
Type: Live.
Primary course: 1 injection.
Dosage: 0.5ml (all ages).
Boosters: Every 10 years.
Route: Deep subcutaneous.
Length of protection: At least 10 years.
Side effects: Severe reactions are extremely rare.
Mild local or systemic reactions may appear in 5-10% of people approximately 5-10 days following vaccination.
Contraindications: Infants < 9 mths,the immunocompromised. Serious egg allergy. Pregnancy (no serious problems have been observed when given inadvertently). Breastfeeding is not a contraindication.
Availability: Yellow fever vaccine is only given at registered and designated yellow fever centres.

Yellow fever vaccination certificates

There is always the possibility that a traveller without an up to date certificate will be detained in isolation at the port of arrival or repatriated if certificates are legally required.
A certificate saying yellow fever vaccination is contraindicated for medical reasons may be accepted by immigration authorities. This exemption can be written on the official WHO certificate or on practice notepaper but must be formally stamped.

Notes
01/03/99. Shortage of yellow fever vaccine - Due to a change in the antigen used in the production of yellow fever vaccine there is currently no licensed product available.
This has caused difficulties for travellers who require vaccination for personal protection or need certificates for immigration purposes.
An unlicensed product can usually be obtained from Medeva (01372 364000) which can then be administered on a named patient basis.
Alternatively it may be necessary for the traveller to contact yellow fever centres outside their area to see if they can find find any remaining stocks.
27/11/98. Global Figures for 1996-1997. In 1996, 424 cases with 141 deaths - case fatality rate (CFR 53%) were reported from endemic areas in Africa amd S.America. There were 190 cases with 89 fatalities in 1997 (CFR 47%).
During the 5 yr period 1993-1997 the range of countries reporting cases has expanded while the number of reported cases has fallen. This may be due to less efficient surveillance and obscures the risk that a large yellow fever outbreak could spread from an endemic focus. (WHO/WER 1998/73/46 (For individual figures see country concerned )