The number of suspected Ebola cases in the outbreak in north-eastern Congo has been sharply cut after officials said testing had ruled out hundreds of infections.

The latest World Health Organization (WHO) figures said there had been 321 ‌confirmed cases in the Democratic Republic of Congo (DRC) and 116 suspected cases.

Officials also said there had been 48 deaths from the rare Bundibugyo strain centred on DRC’s Ituri province.

The tally marked a continued rise in confirmed cases and deaths, but a large fall in suspected cases, down from over 1,000 reported late last week.

Dr Tedros Adhanom Ghebreyesus, head of the World Health Organization (WHO), told journalists at a press briefing on Wednesday that large numbers of suspected cases had now been discounted “either confirming them or ruling them out”.

A suspected case ‌included anyone who was picked up ⁠by surveillance or who presents with symptoms at a health centre, he added. These could then be tested and ruled out. Confirmed cases only included those who had tested positive.

Dr Nicholas Davies, an associate professor at the London School of Hygiene and Tropical Medicine, said that the drop in suspected cases is “normal” in outbreaks like this, when doctors are on high alert for anyone who might be infected with the virus.

“It is actually a sign that the clinical response is proceeding well. Ebola is a really nasty disease, but in its early stages it can be difficult to distinguish it clinically from other diseases like malaria,” said Dr Davies.

“Because of the concern over this current outbreak, a lot of patients are placed under investigation to either rule out or confirm Ebola,” he told The Telegraph.

A lack of testing has hampered the response for weeks and contributed to the virus circulating undetected, possibly for months before an outbreak was confirmed in mid-May.

Sources told The Telegraph that local health authorities in Ituri believed the index case of the current outbreak came in January, four months before the outbreak was officially declared.

Testing kits available to medics were only able to detect the more common Zaire strain which has been responsible for most DRC outbreaks over the past 50 years.

Dr Tedros said only 45 per cent of people who are contacts of infected Ebola patients had been traced, a figure that needed to increase to at least 90 per cent to contain the outbreak.

Meanwhile, a Kenyan court extended a block on a proposed American quarantine centre that has triggered widespread protests.

The proposed 50-bed unit on an air force base in central Kenya to house Americans exposed to the virus in DRC or Uganda has now been blocked for another three weeks.

The scheme has angered many Kenyans, who fear it will import the disease and accuse their government of compromising their sovereignty for money.

Protests at the weekend against the scheme saw two killed.

The court last week temporarily suspended the centre plan in response to a lawsuit from a legal advocacy group.

Yet US military aircraft have reportedly continued to fly in staff and equipment in recent days.

The Trump administration has said it believes an agreement can still be reached.

Mehmet Oz, a surgeon and former TV presenter who is now a senior health official in the Trump administration, said: “I think we’re going to work out ... a very favourable arrangement with Kenya.”

“They’re going to do the right thing for everybody, and I think it’s a perfect solution.”

Marco Rubio, US secretary of state, said the Trump administration was discussing appointing a single official to lead its response ‌to ‌the outbreak.

Mr Rubio told “I don’t want to use the term ‘Ebola ⁠czar’, but [it would be] someone with the qualifications to sort of serve full time in ‌the coordination of the inter-agency.”

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