First British national to have contracted deadly virus arrives at RAF Northolt in west London after evacuation from Sierra Leone

A healthcare worker who is the first Briton confirmed to have tested positive for the Ebola virus was flown to London on Sunday for treatment after being evacuated from Sierra Leone on an RAF plane.

The Department of Health said he was "not currently seriously unwell" in a statement issued shortly after the C-17 aircraft took off from Freetown for RAF Northolt in west London where it landed at 9pm.

A US scientist who worked with the man named him as William Pooley, a 29-year-old volunteer nurse, the BBC reported.

The man was expected to be taken to the Royal Free hospital in Hampstead, London, which has an isolation unit where he can be treated.

The man, who lives in Sierra Leone, had been volunteering at an Ebola clinic in the Kenema district in the east of the country.

The number of people infected with the deadly virus has been put at 2,615 by the World Health Organisation. The disease was identified in Guinea in March and spread to Sierra Leone, Liberia and Nigeria – 1,427 victims have died.

The decision to fly the British man home was taken on Saturday at a meeting between the medical director of the NHS, Sir Bruce Keogh, the health secretary, Jeremy Hunt, and the foreign secretary, Philip Hammond. A medical assessment was carried out to see whether the patient was fit to fly.

"The patient is not currently seriously unwell and is being medically evacuated in a specially equipped C-17 Royal Air Force plane to RAF Northolt in the UK. Upon arrival in the UK, the patient will be transported to an isolation unit at the Royal Free London NHS Foundation Trust," a statement from the Department of Health said on Sunday. Prof John Watson, the deputy chief medical officer for England, said the risk to the public remained low. "We have robust, well-developed and well-tested NHS systems for managing unusual infectious diseases when they arise, supported by a wide range of experts," he said.

"UK hospitals have a proven record of dealing with imported infectious diseases and this patient will be isolated and will receive the best care possible."

Dr Paul Cosford, the director for health protection at Public Health England, said protective measures will be maintained to minimise the risk of transmitting the virus. "For Ebola to be transmitted from one person to another, contact with blood or other body fluids is needed and, as such, the risk to the general population remains very low," he said.

The RAF flight took off from Freetown-Lungi airport. "I saw it [the plane] sitting there for more than one hour before it took off. Some doctors assisted the man on board," an airport official said.

The isolation unit at the Royal Free hospital has specialist equipment to help contain the infection. The bed is surrounded by a specially-designed tent with a controlled ventilation system and a specific hospital entrance is used for transit.

Waste is decontaminated and there is a dedicated laboratory to carry out tests. All the air leaving the unit is cleaned to minimise the risk to anyone at the hospital, the hospital said.

Tom Dannatt, founder of the British charity Street Child which works in Sierra Leone and West Point in Liberia, said the spread of Ebola had spiralled from a health emergency into a humanitarian disaster. He said the Liberian township of West Point was "a tense, grim, impoverished slum at any time" and is now barricaded.

"They are now totally cut off from the world with uncertain access to food and water – and a terrifying disease from which they do not fully understand how to protect themselves," he said.

Last week, Médecins sans Frontières said the international community was paying "almost zero" interest to the growing health crisis. The first confirmed case of a British person contracting the virus comes after two US citizens were last week discharged from hospital after receiving experimental medications.

Countries in west Africa face ever growing isolation in their attempts to combat Ebola, as Ivory Coast became the latest state to close its borders with affected countries and the Philippines withdrew peacekeepers from the region.

Ivory Coast shut its border with Liberia after cases of the disease were reported on the border, and also with Guinea.

Doctors in Freetown said patients are shunning hospitals because of the fear of catching Ebola, even though the city has had only 12 cases in a population of 1 million. Two large city hospitals in the capital were mostly empty on Sunday, with few patients to be seen.

The streets of Freetown are quieter than usual and people have been avoiding large crowds. The World Health Organisation has sent 400 people to help fight the epidemic and on Sunday revealed that one of its experts had contracted the disease in Sierra Leone.

At Freetown airport passengers arriving and departing have to wash their hands twice, have their temperature taken and fill in a form.

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