* Ebola has killed 2,811 in West Africa -WHO
* Sierra Leone lauds "lockdown", needs "footsoldiers" in clinics
* Guinea arrests 20 over killings of health workers
* Tekmira authorized to use Ebola treatment
By Umaru Fofana
FREETOWN, Sept 22 (Reuters) - An outbreak of Ebola in West Africa has been largely contained in Senegal and Nigeria, the World Health Organisation (WHO) said on Monday, but the disease is still spreading elsewhere and has now killed over 2,811 people in the region.
Senegal and Nigeria, the most recent of five nations to record cases of Ebola, implemented strict measures to isolate the ill and track down further possible cases -- steps that Guinea, Liberia and Sierra Leone have failed to impose, allowing the disease to take hold in cities and rural communities.
Sierra Leone said it had registered 130 new cases of Ebola during a three-day national lockdown that ended late on Sunday, the most radical move yet to try to contain a disease that has killed around half of those it infects and is crippling some of the weakest countries in West Africa.
The current outbreak was first identified in the forests of southeastern Guinea in March and then spread into neighbouring Liberia and Sierra Leone, where it overwhelmed weak national health systems.
In Nigeria, 20 cases were recorded and eight people died. There have been no deaths from one confirmed case in Senegal.
"On the whole, the outbreaks in Senegal and Nigeria are pretty much contained," a WHO statement said.
However, the U.N. agency said the world's worst outbreak of the virus remains a "public health emergency of international concern", which will guarantee it the body's priority attention.
The international response has failed to match the spread of a disease that has exposed the fragility of the state in Guinea and threatened to undo progress made in rebuilding Liberia and Sierra Leone after their wars of the 1990s.
Donors have since pledged hundreds of millions of dollars in aid and the U.S. government is scrambling 3,000 soldiers to the region to build an extra 17 treatment centres and train thousands of local medics.
The Pentagon said about 60 U.S. military personnel had arrived in the region so far and another 30-40 are scheduled to arrive in the next few days.
The U.S. plan has been welcomed but aid workers say other rich nations should follow Washington's lead with cash, supplies and personnel. The WHO has said the world must act quickly to keep the number of cases in the tens of thousands.
The European Union has pledged 140 million euros ($180 million) to fight the virus and Beatrice Lorenzin, Italy's health minister, said European countries are assessing their resources to plan a coordinated response.
"Only four or five countries in Europe are equipped. We will work together to coordinate the aid effort," she said as EU health ministers met in Milan on Monday.
Ebola has prompted a range of policy measures from African governments, including border closures and travel bans, though none as severe as Sierra Leone, where residents emerged on Monday from a 72-hour lockdown.
Authorities say they reached more than 80 percent of households targeted in their sensitization campaign.
"The outreach was just overwhelming," Stephen Gaojia, head of the Ebola Emergency Operations Centre, said on Monday.
The country now needs to focus on treatment and case management and it urgently requires treatment centres in all its 14 districts as well as "foot soldiers" in clinics and hospitals, he said.
The government is still waiting for results from a further 39 suspected cases, Gaojia said. There were no new deaths in Guinea, four in Sierra Leone and 39 in Liberia, according to the latest figures from the WHO.
Authorities in Guinea said they have arrested 20 people as part of an investigation into the killing last week of nine members of a delegation attempting to educate people about Ebola in a remote part of the southeast of the country.
The killings underscored how much some rural populations in the affected countries mistrust authorities after years of instability and conflict.
A separate, unrelated, Ebola outbreak has killed 41 people in Democratic Republic of Congo, where there have been 68 cases, WHO said in a statement on the situation as of Sept 18.
Independent health advisers to the WHO have assessed that there should be no general ban on travel or trade with countries where the virus has struck, but some airlines have maintained suspensions on flights to affected areas.
The WHO and other agencies this say this hampers aid efforts and the ability of experts to reach victims. "The (WHO Emergency) Committee strongly reiterated that there should be no general ban on international travel or trade," WHO said.
Canadian drugmaker Tekmira Pharmaceuticals Corp said on Monday that U.S. and Canadian regulators have authorized the use of its Ebola treatment in patients who have confirmed or suspected infections.
The Vancouver-based company said its treatment, TKM-Ebola, has been administered to patients on an emergency basis and the repeat infusions have been well-tolerated.
An elderly Spanish priest, in a serious condition after being infected in Sierra Leone, will not receive the experimental drug ZMapp because world supplies are exhausted, Madrid health authorities said on Monday.
ZMapp was used to treat several Ebola patients who recovered. Its use is part of a push by drug manufacturers to devise a cure or a vaccine for the disease, which has killed about 48 percent of those infected in the current epidemic.
Manuel Garcia Viejo, 69, was taken to Madrid's Carlos III hospital at about 0200 GMT after he was repatriated. (Additional reporting by Saliou Samb in Conakry, Tom Miles and Stephanie Nebehay in Geneva, Raquel Castillo in Madrid, Ilaria Polleschi in Milan, Amrutha Penumudi in Bangalore and Rod Nickel in Winnipeg, Phillip Stewart in Washington; Writing by Matthew Mpoke Bigg; Editing by David Lewis and Sonya Hepinstall)