DANGEROUS WORK: Workers from Doctors Without Borders unload emergency medical supplies to deal with an Ebola outbreak in Conakry, Guinea, on Sunday. Picture: REUTERS

Five people are suspected to have died from the disease in Lofa county in northern Liberia, Bernice Dahn, Liberia?s chief medical officer, said at a briefing on Tuesday. At least 86 cases and 59 deaths have been recorded across Guinea, the west African country?s health ministry said. The capital, Conakry, has not been affected, government spokesman Albert Damantang Camara said.CONAKRY — Africa?s biggest Ebola outbreak in seven years has probably spread from Guinea to neighbouring Liberia and also threatens Sierra Leone.

"The forest region where UNICEF delivered the emergency assistance on Saturday is located along the border with Sierra Leone and Liberia with many people doing business and moving between the three countries," said Laurent Duvillier, a UNICEF spokesman, on Tuesday. "Risk of international spread should be taken seriously."

UNICEF plans to dispatch five tonnes of aid, including medical supplies, to the worst-affected areas. Suspected cases of the lethal haemorrhagic disease are being probed in Guinea?s southeast border areas, says the World Health Organisation (WHO).

"The three cases which were registered in Conakry have no link with Ebola," Mr Camara said. "The analyses were made abroad. The outbreak of the disease may be heavier than 59 but the health ministry will release a statement on the disease soon."

The Geneva-based WHO hasn?t previously recorded outbreaks of Ebola in Guinea, the world?s biggest exporter of bauxite, the ore used to make aluminium. At least eight health workers in contact with patients have died, hindering the response and threatening normal care in a country already lacking medical personnel, UNICEF said.

"This outbreak is particularly devastating because medical staff are among the first victims," New York-based UNICEF said. There is no specific treatment or vaccine for Ebola.

Supplies delivered over the weekend are being distributed to healthcare workers, said Timothy La Rose, a UNICEF spokesman.

"We are focusing on prevention," Mr La Rose said. "We are alerting the public on how to avoid contracting Ebola. Since there is no treatment, this is the best way to stop the spread."

Medecins Sans Frontieres is setting up isolation and treatment units and workers at Rio Tinto?s operations have been issued with personal protection equipment. The five latest cases were in the towns of Gueckedou and Macenta, it said.

The Ebola virus is transmitted through contact with blood or bodily fluids of an infected person or wild animal, says the WHO. It was first identified in 1976 in Congo and Sudan, when two different strains of the virus killed 431 of the 602 people infected.

Mali and Ivory Coast called for vigilance to prevent the disease spreading across their borders. They border Guinea with Liberia, Sierra Leone, Guinea-Bissau and Senegal. Mali?s government on Tuesday warned against unnecessary travel to the contaminated area, after the health ministry held a crisis meeting and called on citizens to be "vigilant." Liberia?s New Democrat newspaper ran an editorial in which it said there was an immediate need for increased surveillance on all border posts with Guinea. Many of the goods sold in Monrovia, Liberia?s capital, come from Guinea.

Ivory Coast set up a co-ordinating post in Man on the border with Guinea and will increase surveillance and run awareness campaigns, the country?s health ministry said.

Gambia, an enclave in Senegal, is monitoring the situation, its health ministry said. SA?s National Institute of Communicable Diseases has issued an alert for port health authorities to examine travelers from Guinea with possible symptoms of the disease, Johannesburg?s Business Day newspaper said.

A man in Canada who showed symptoms similar to Ebola after travelling to Liberia tested negative for the virus, Gregory Hartl, a WHO spokesman, said on Twitter on Wednesday.

Recent Ebola outbreaks have occurred in the Democratic Republic of Congo in 2012 and in Uganda in 2011.