The West African state of Senegal became the fifth country to be touched by the world's worst Ebola outbreak yesterday, while riots broke out in neighbouring Guinea where infection rates are rising fast.
The deadly virus has defied efforts by governments to control it, prompting Medicins Sans Frontieres, the leading charity fighting the outbreak, to call for the UN Security Council to take charge of efforts to stop the epidemic.
At least 1,550 people have died of Ebola and more than 3,000 have been infected since the virus was detected in March.
In the Guinean city of Nzerekore, riots broke out on Thursday night over rumours that health workers had infected people with the Ebola virus, a Red Cross official and residents said.
A crowd of young men, some armed with clubs and knives, set up barricades across the southern city and threatened to attack the hospital before security forces moved in to restore order.
Senegal's Health Minister Awa Marie Coll Seck said the country's first case was a Guinean student who turned up for treatment at a hospital in the capital Dakar on Tuesday, concealing the fact that he had close contact with victims in his home country.
Authorities in Guinea had been searching for the young man for three weeks since he evaded surveillance.
"We are tracing his whole itinerary and also identifying anyone who had contact with the patient who, now that he has been diagnosed, is much more cooperative and supplying all the necessary information," the minister said.
In the latest sign that the outbreak is out of control, the WHO said yesterday that the number of cases rose by the highest weekly amount since the epidemic began in Guinea, Liberia and Sierra Leone.