Only five out of 92 beds are in use at a British-funded Ebola hospital in Sierra Leone which opened three weeks ago, Conservative MP Sir Edward Garnier said during Prime Minister's Questions.
The facility in Kerry Town cost £2 million to build and is being run by charity Save the Children.
Sir Edward told the Prime Minister: "As of last night, it was looking after five patients.
"Would you have a word with [International Development Secretary Justine Greening] and others in Government to make sure that hospital is made proper use of?"
Mr Cameron agreed and said the Government was working "intensively" with Save the Children to ensure the hospital reaches its full capacity.
A Government spokesman stressed that 443 treatment beds and isolation places in total are operational in Sierra Leone "because of Britain's response".
"We are providing 211 Ebola beds in treatment facilities that the UK has built, expanded or kept open and 232 beds and places in local community care centres where Ebola sufferers are going for initial care and diagnosis," he added.
Save the Children said the figure quoted by Sir Edward during PMQs "was not accurate."
Thirty NHS volunteers are now on their way to the heart of the Ebola epidemic in West Africa.
The doctors, nurses and support staff are the first of several NHS teams who are giving up their Christmases at home to join British soldiers, scientists and aid workers already in Sierra Leone.
Sejal Karia met them as they said a final goodbye to their loved ones at Heathrow.
The first volunteers from the NHS depart for Sierra Leone today to join the continuing fight against Ebola.Read the full story ›
Former Prime Minister Tony Blair has visited Sierra Leone to visit those leading the Ebola response in the country.
He praised the efforts of British troops helping to fight the virus.
“I saw British armed forces at work in Sierra Leone. They are top quality people & are doing a great job.” Tony Blair http://t.co/cGzfQIuJu4
A British-funded treatment centre in Sierra Leone is accepting its first Ebola patients.Read the full story ›
The head of the UN's Ebola mission has compared the disease in Sierra Leone to "a bush fire raging out of control".
But the country's president, Ernest Bai Koromo, has told ITV News in a rare interview that his government is "getting a grip" on the deadly virus.
ITV News Correspondent Dan Rivers reports from Freetown, Sierra Leone:
Workers tackling Ebola in Sierra Leone are concentrating on changing burial traditions in an attempt to stem the spread of the disease.Read the full story ›
Britain's response to the spread of Ebola in west Africa stepped up as a team of 120 army medics touched down in Sierra Leone.
They join 40 British soldiers already deployed there - with many more due to arrive next month.
As the World Health Organisation confirmed the number of recorded deaths from the virus will pass 4,500 this week, ITV News Correspondent Dan Rivers reports on the crisis in Africa: