By Umaru Fofana
FREETOWN (Reuters) - Sierra Leone declared a state of emergency and called in troops to quarantine Ebola victims on Thursday, joining neighbouring Liberia in imposing tough controls as the death toll from the worst-ever outbreak of the virus hit 729 in West Africa.
The World Health Organisation said it was in urgent talks with donors and international agencies to deploy more medical staff and resources to one of the world's poorest regions.
The WHO reported 57 new deaths between July 24 and July 27 in Guinea, Liberia, Sierra Leone and Nigeria.
Authorities in Nigeria, which recorded its first Ebola case last week when a U.S. citizen died after arriving on a flight from Liberia, said all passengers travelling from areas at risk would be temperature-screened for the virus.
In a measure of rising international concern, Britain on Wednesday held a government meeting on Ebola and called it a threat requiring a response. The White House has also said President Barack Obama was being briefed on the situation.
But international airlines association IATA said the WHO was not recommending any travel restrictions or border closures due to the outbreak, and there would be a low risk to other passengers if an Ebola patient flew..
The outbreak of the hemorrhagic fever, for which there is no known cure, began in the forests of remote eastern Guinea in February, but Sierra Leone now has the highest number of cases.
Sierra Leone President Ernest Bai Koroma said he would meet with the leaders of Liberia and Guinea in Conakry on Friday to discuss ways to combat the epidemic. He cancelled a visit to Washington for a U.S.-Africa summit next week.
"Sierra Leone is in a great fight ... Failure is not an option," Koroma said in a speech late on Wednesday, adding that the state of emergency would initially last between 60 and 90 days. "Extraordinary challenges require extraordinary measures."
He said police and the military would enforce a quarantine on all epicentres of the disease, and would help health officers and NGOs do their work unhindered, following a number of attacks on health workers by local communities.
House-to-house searches would be implemented to trace Ebola victims and homes where the disease was identified would be quarantined until cleared by medical teams, he said, announcing a ban on all public meetings except those related to Ebola.
The moves echoed a raft of measures unveiled by Liberia on Wednesday, which included the closure of all schools across the country and a possible quarantine of affected communities.
NEW AIRPORT CONTROLS
The disease kills up to 90 percent of those infected, though the fatality rate in the current epidemic is running at around 60 percent. In the final stages, its symptoms include external bleeding, massive internal bleeding, vomiting and diarrhoea - at which point the virus becomes highly contagious. Sierra Leone, a former British colony, said passengers arriving and departing Lungi International Airport would be subject to new protocols, including body temperature scans.
Two regional airlines, Nigeria's Arik and Asky, have cancelled all flights to Freetown and Monrovia after a U.S. citizen, Patrick Sawyer, died in Lagos last week after arriving on an Asky flight from Liberia.
The WHO said authorities in Nigeria had identified 59 people in the airport and hospital who had come into contact with Sawyer, whose flight also stopped in Ghana and Togo.
Nigeria's Civil Aviation Authority (NCAA) suspended Asky for bringing Ebola to Lagos, a teeming mega-city of 21 million people. Many people had questioned how a person showing signs of the disease - whose sister had died of it three weeks previous - had been able to board an international flight.
Health officials are scrambling to avoid the nightmare scenario of an Ebola outbreak in Lagos, the continent's biggest metropolis, but say there are so far no signs of further cases.
Ghana also announced on Thursday it was introducing body temperature screening of all travellers from West African countries at Accra airport and other major entry points, with isolation centres being set up in three towns.
Kyei Faried, deputy director in charge of disease control, told a news conference that authorities had a list of 11 passengers who disembarked from Sawyer's flight and were monitoring them. The government is considering whether to ban flights from affected countries.
The U.S. Peace Corps said it was withdrawing 340 volunteers from Liberia, Sierra Leone and Guinea after two of them came in contact with a person who later died of the virus.