Other countries (e. g. French Guiana and Guyana) have recently included yellow fever vaccination in their national routine programme for immunization.
The yellow fever virus is constantly present in mosquitos and non-human primates in some tropical areas of Africa and the Americas.
Several different species of the Aedes and Haemogogus (South America only) mosquitos transmit the yellow fever virus.
In addition, in the past, yellow fever outbreaks also occurred in Europe, the Caribbean islands and Central and North America
Therefore, although yellow fever has never been reported from Asia, this region is at risk because the appropriate mosquitos and primates are present.
The notifications to WHO in 1998--1999 DO not reflect accurately the number of yellow fever cases that occur annually, particularly in Africa.
Certain mosquitoes spread malaria and yellow fever germs. They get the germ when they bite a person who HAS the disease.
Travelers are reminded that inoculation against yellow fever is advisable
In 1988, WHO first recommended that at-risk countries incorporate yellow fever vaccine into the routine childhood immunization programmes.
Disease surveillance is not adequate to detect cases of sylvatic yellow fever that often occur in remote areas.