* Four cases of Ebola confirmed in Conakry
* Regional foreign ministers call outbreak a security threat
* At least 63 people have died from the virus (Adds details, background)
By Saliou Samb
CONAKRY, March 27 (Reuters) - A deadly outbreak of the Ebola virus suspected of killing at least 63 people has spread from rural Guinea to the capital Conakry, authorities said on Thursday, after West African nations branded the virus a serious threat to regional security.
Guinean Health Minister Remy Lamah told Reuters that four cases of the haemorrhagic fever - one of the most lethal infectious diseases known to man - had been confirmed in the capital and the victims had been placed in quarantine.
The spread of Ebola to Conakry, a city of some 2 million people, marked an escalation in the outbreak in Guinea, which ranks as one of the poorest nations on earth despite rich deposits of bauxite and iron ore which attract international mining companies.
As of Wednesday, 63 deaths had been reported from suspected cases in Guinea’s remote southeast Forest Region. At least six more people have died in Sierra Leone and Liberia from Ebola-like symptoms, most of them after crossing over from Guinea.
Lamah said the virus appeared to have been transmitted by an old man who showed signs of haemorrhagic fever after visiting Dinguiraye in central Guinea, more than 150 km (90 miles) from the previously identified outbreaks of Ebola.
Four of the man’s brothers started to show the same symptoms after attending his funeral in the central town of Dabola, 200 km (125 miles) from Conakry, and were tested for Ebola on their return to the coastal capital.
“The four tested positive,” Lamah told Reuters. “They have been placed in an isolation ward in Donka hospital.”
The old man’s family has also been quarantined, the minister said.
Medical sources said two staff at the Kipe University Hospital in Conakry, where the victims had initially been treated, had also developed signs of the disease.
Discovered in 1976 after an outbreak in the Democratic Republic of Congo, then Zaire, Ebola causes a severe haemorrhagic fever in which victims suffer vomiting, diarrhoea and both internal and external bleeding.
Since its discovery, Ebola, named after a river in northern Congo, is known to have killed more than 1,500 people. There is no cure or vaccine, partly because the rarity of the disease makes drug development difficult.
A mysterious fever was first detected in Guinea in early February but it took authorities nearly six weeks to identify it, allowing the virus to spread. Ebola has an incubation period of up to three weeks.
It was the first fatal outbreak of the disease recorded in West Africa. It is more commonly found in Congo, Uganda and Sudan.
Guinea, where the few hospitals are not equipped to deal with the problem, has turned to medical charities and U.N. agencies for help. Medical charity Doctors Without Borders (MSF) flew in 33 tonnes of supplies at the weekend.
Foreign ministers from across West Africa - one of the world’s poorest and most underdeveloped regions - have voiced “deep concern” at the outbreak, according to a communique issued after a meeting of the regional bloc ECOWAS in Ivory Coast.
Branding it “a serious threat to regional security”, ministers appealed for international assistance to control the epidemic, the communique said.
Experts say Ebola’s suspected origin - what they call the “reservoir host” - is forest bats. Links have also been made to the carcasses of freshly slaughtered “bushmeat” animals.
In an effort to halt the transmission of the disease, Guinea and neighbouring countries have banned consumption of bat and other forms of bushmeat - a regional delicacy often eaten in a peppery soup. Guinea has also forbidden public funerals for victims and bodies are being disposed of by the Red Cross.
Regional airline Gambia Bird has announced that it will delay the launch of services to Conakry, due to start on Sunday, because of the outbreak.
To the north, Mauritania announced it was closing all but two of its southern border crossings with Senegal and imposed strict sanitary controls at those. (Additional reporting by Misha Hussain of the Thomson Reuters Foundation in Dakar, Laurent Prieur in Nouakchott; Writing by Daniel Flynn; Editing by David Lewis and Andrew Roche)