Emergencies preparedness, response

2000 - Rift Valley fever in Yemen - Update

03 October 2000

Disease Outbreak Reported

As of 2 October, 321 suspected cases of Rift Valley fever (RVF) with 32 deaths have been reported in Yemen.

In Yemen, 8 teams of physicians and veterinarians are conducting active surveillance in the outbreak area. The epicentre of the outbreak is in Wadi Mawr, El-Zuhrah district in Hodeidah Governorate. The mean age of affected patients is 36.5 years (range 2 months to 90 years).

Confirmed cases of disease have been detected in villages throughout Wadi Mawr. Laboratory capability has been established to detect IgM and IgG class antibody to RVF. Of 59 persons who met the suspect case definition, 29 (51%) had IgM anti-RVF antibody.  Results of surveys in animals from the outbreak area and adjacent Wadis will be available in the next few days.  Surveillance for disease in animals has detected considerable morbidity and mortality in sheep, goats and cattle (most of which has been reported in Wadi Mawr).

Surveillance in humans and animals is ongoing in these sites to determine the extent of possible transmission.  Surveillance data in humans and animals is being used to define high-risk areas which are being targeted for vector control. Efforts are being made to build local capacity to respond to the outbreak, including training on laboratory methods, vector control and surveillance.

This outbreak has occurred at the same time as the outbreak of RVF in Saudi Arabia (see previous report). WHO advises that persons can travel freely to and from both Yemen and Saudi Arabia. Persons travelling within the affected districts should wear long-sleeved shirts and trousers and should use mosquito repellent and bednets, and avoid contact with sick livestock.