Death toll rises as Rift Valley Fever spreads

At least 60 people in Kenya's Northeastern Province are now known to have died from Rift Valley Fever (RVF), while health experts are warning that the virus may have begun spreading south.

"All evidence suggests that the disease is still spreading," said Kariuki Njenga, a virologist and laboratory director for the United States Centers for Disease Control (CDC) in Kenya.

The worst affected districts in the Northeastern Province are Garissa, where 100 cases, including 40 deaths, have been reported; and Ijara, where 20 out of 42 people infected with RVF have died, Njenga said.

Cases of the disease have also been reported in Wajir and Tana River districts. One confirmed case has been reported in Kilifi District of the Coast Province, the latest area to report RVF infection since the disease was first identified in Garissa in early December.

The CDC has set up a field laboratory in Garissa to test suspected cases of the fever, and is helping the Kenyan livestock ministry to develop a vaccination strategy.

The RVF virus is spread to humans from livestock via the aedes mosquito, which breeds rapidly during floods. The Northeastern Province, inhabited by nomadic pastoralists, was hit by devastating floods over the last three months of 2006, following heavier than normal rainfall.

It can be transmitted through contact with infected animal material, such as blood or other body fluids, or organs. Consumption of milk, a staple for many pastoral people, is also thought to lead to infection. Symptoms in humans include bleeding through the nose and mouth, and liver failure.

Njenga said a major livestock vaccination campaign in the affected areas would start on Monday and that aerial spraying against mosquitoes was also being planned.

Northeastern Province was previously hit by an outbreak of RVF in 1997 following heavy flooding caused by the El Nino weather pattern. Njenga said that it had become apparent that heavy rainfall and floods were related to RVF outbreaks in pastoralist areas.

"The government should therefore have a policy of pre-vaccination before the onset of the long rains to prevent outbreaks," said Njenga. "The disease is preventable with pre-vaccination."

The government has banned the slaughter of livestock in the affected areas, leading to the closure of livestock markets in a region where people depend on animals for income and food.

The disease was first identified in Kenya in 1931. The World Health Organisation (WHO) says it occurs in epidemics in animals in Africa, and is associated with spontaneous abortions in sheep, goats and cattle, and deaths in young animals.

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