WHO Report on Global Surveillance of Epidemic-prone Infectious Diseases - Yellow fever
- The six-year period from 1986 to 1992 represents a remarkably active period for yellow fever and represents the greatest amount of yellow fever reported to WHO for any such period since 1950. The reported number of cases of yellow fever has declined since 1994, although the number of countries reporting yellow fever has not (Fig. 2.3 and Table 2.2).
- Reported case fatality rates for reported cases of yellow fever are high, often greater than 50% of all cases reported.
- To prevent epidemics, it is estimated that at least 80% of the population should have acquired immunity to yellow fever. At present, only two countries have reported achieving 50% coverage - namely Côte d'Ivoire and the Gambia.
- In terms of childhood immunization, two very small countries, Trinidad and Tobago and the Seychelles, have reported over 90% coverage, and Venezuela, Senegal and Côte d'Ivoire have reported over 50% coverage. Other countries have either not reported during the last three years or have lower coverage rates.
Fig 2.3 Reported number of cases of yellow fever, 1950-1998