In November 23, 1999, the WHO reported a death due to yellow fever in a 48 year old unvaccinated man who had recently traveled to Bolivar State, which is in south east Venezuela and part of the Amazon rain forest ecosystem. The individual became ill on September 23, while in Bolivar State and returned to California, USA, on September 25. Two days later he was hospitalized with fulminant hepatitis and renal failure and on October 4, he died. Yellow fever viral infection was confirmed by immunohistochemistry and PCR. The Venezuelan authorities are currently conducting a field investigation.

We wish to draw to your attention the occurrence of sylvatic yellow fever outbreaks in similar geographic areas of Venezuela, Brazil and French Guiana during 1998 [CAREC Fax alert 23/09/98, CAREC CDFR 04-98].

The potential for urban transmission of yellow fever exists in the Caribbean, due to the large and increasing amount of travel occurring to and from high risk areas and the high indices of the Aedes aegypti mosquito in most countries. Thus, to facilitate the early detection and effective management of cases and rapid control of outbreaks, a vigilant and sensitive surveillance system is essential for all countries in the region. Physicians need to have a high index of suspicion and remember to take a travel history in persons with unexplained fever. Laboratory support is also crucial to such a system to ensure accurate diagnosis of acute febrile cases with haemorrhagic and/or jaundice manifestations.

Please be reminded of the vital importance for all travellers to be vaccinated against yellow fever at least 10 days before visiting endemic areas. While vaccination is the preferred method for the prevention and control of yellow fever, the strengthening of Aedes aegypti control programmes is also a key factor in the prevention of urban yellow fever outbreaks.

Please notify CAREC in advance if clinical specimens are being referred to our laboratories for yellow fever diagnosis. [Epidemiology Division: 868-622-2152, Laboratory Division: 868-628-1032]

Dr. Merle J Lewis
Manager
Epidemiology Division
CAREC