Since October 2008, an intense increase in the circulation of the jungle yellow fever (JYF) virus has been observed in the Americas, affecting Argentina and Brazil in the southern part of the continent, Colombia and Venezuela in the Andean region, and Trinidad and Tobago in the Caribbean. 

 
The objective of this communication is to alert the countries of the Region so that they can strengthen their surveillance, prevention, and control activities for yellow fever within their territories and for persons traveling towards affected or risk areas. 

 Epidemiological Alert: Increase in Circulation of Jungle Yellow Fever Virus in the Americas