(adds details, quotes)
GENEVA, July 31 (Reuters) - The World Health Organisation is launching a $100 million response plan to combat an "unprecedented" outbreak of Ebola in West Africa that has killed 729 people out of 1,323 infected since February, the U.N. agency said on Thursday.
WHO Director-General Margaret Chan will meet in Conakry, Guinea on Friday with the presidents of affected West African nations, it said in a statement.
"The scale of the Ebola outbreak, and the persistent threat it poses, requires WHO and Guinea, Liberia and Sierra Leone to take the response to a new level and this will require increased resources, in-country medical expertise, regional preparedness and coordination," said Chan.
The plan identifies the need for "several hundred more personnel" to be deployed in affected countries to ease the strain on overstretched treatment facilities, the WHO said. Clinical doctors and nurses, epidemiologists, and logisticians are urgently needed, it said in an appeal to donor countries.
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 plan sets out new needs to respond to the outbreak across the countries and bring up the level of preparedness in neighbouring countries," WHO spokesman Paul Garwood said. "They need better information and infection-control measures."
The plan aims to stop transmission of the virus by strengthening disease surveillance, particularly in border areas, protecting health workers from infection and doing a better job of explaining the disease to communities.
(Reporting by Stephanie Nebehay; Editing by Mark Heinrich)