Ebola spread 'bigger than expected' - WHO Published duration 10 October 2014

image caption The first three people in Africa have been vaccinated with an experimental serum against Ebola in Mali

Leading global health experts did not anticipate the scale of the Ebola outbreak, a senior health official has told the BBC.

Chris Dye from the World Health Organization (WHO) said the international response was helping but needed to continue.

Ebola is now entrenched in the capitals of the worst-affected states - Guinea, Liberia and Sierra Leone, WHO says.

The outbreak has killed more than 3,860 people, mainly in West Africa.

More than 200 health workers are among the victims.

media caption WHO's Dr Chris Dye: We didn't anticipate this outbreak was going to be this big

Mr Dye said that that although no-one was in a position to anticipate the scale of the current outbreak, the important thing was to look forward.

"We've asked for a response of about $1bn (£618m); so far we have around $300m (£185m) with more being pledged, so a bit less than half of what we need but it's climbing quickly all the time," he said.

In April, the medical charity Medecins Sans Frontieres (MSF) warned of the potential spread of the virus, but the WHO played down the claims , saying that Ebola was neither an epidemic, nor was it unprecedented.

On Friday MSF reported a sharp increase of Ebola cases in the Guinean capital, Conakry, dashing hopes that the disease was being stabilised there.

Meanwhile in Mali, an experimental serum is being tested on volunteer health workers.

The trial spans several countries, and the results will be sent to experts to determine whether it is able to protect against Ebola.

image caption Results of the clinical trial span several countries in the region, and results will be sent to a team of experts

image copyright EPA image caption Ebola is taking a particularly heavy toll in Liberia

image copyright Getty Images image caption The US military is building treatment centres to help Liberia cope with the outbreak

Meanwhile in Spain, seven more people are being monitored in hospital for Ebola.

They include two hairdressers who came into contact with Teresa Romero, a Madrid nurse who looked after an Ebola patient who had been repatriated from West Africa.

Ms Romero is now reported to be gravely ill but stable.

In other developments:

Nigeria's military has now confirmed that more than 1,300 Nigerian peacekeeping troops have been quarantined in Liberia after coming into contact with a Sudanese man who later died of the disease. It had earlier denied such reports

In Liberia, senate elections due next week have been postponed to help reduce the risk of voters spreading the virus

More details of how passengers at some British airports will be screened are expected to be announced later on Friday

The US begins its programme of enhanced screening this weekend at five of its major airports, including JFK

A Texas county sheriff deputy quarantined after visiting the home of the first person diagnosed with Ebola in the US has been given the all-clear.

image copyright Reuters image caption The US is preparing to send troops to West Africa to fight Ebola

Avoid direct contact with sick patients

Wear goggles to protect eyes

Clothing and clinical waste should be incinerated and any medical equipment that needs to be kept should be decontaminated

People who recover from Ebola should abstain from sex or use condoms for three months