Health workers in Sudan's Darfur region have begun vaccinating more than two million people against a rare yellow fever outbreak suspected of killing 124 since late September, medics said on Thursday.
The campaign began on Tuesday in West Darfur state and is expected to continue in other affected areas by Saturday, said a joint report from the Sudanese health ministry and the World Health Organisation (WHO).
"As of 20 November, the total number of cases has reached 497, including 124 deaths," it said, adding that most cases are in Central Darfur state.
This is the first yellow fever outbreak in Darfur in 10 or 20 years, WHO country representative Anshu Banerjee told AFP last week, adding that cases were concentrated in rural areas among the nomad population.
Sudan's impoverished western Darfur region has been plagued by conflict since ethnic minority rebels rose against the Arab-dominated Khartoum government in 2003.
The yellow fever virus normally circulates among monkeys but could be linked to more mosquitoes breeding this year after heavy rains and flooding in the region. Mosquitoes can become infected from the primates and transfer the virus to humans, Banerjee said.
There is no specific treatment for the illness found in tropical regions of Africa but it can be contained through the use of bed nets, insect repellents and long clothing.
Vaccination is the most important preventative measure.