NAIROBI, Kenya (AFP) — The Ebola outbreak in the Democratic Republic of Congo is the “fastest growing” ever, African health authorities said Thursday, as the World Health Organization said it had killed 600 people.

Updated numbers issued by the UN health agency showed there have been 1,759 confirmed cases in DR Congo since the outbreak was declared in mid-May, including 600 confirmed deaths.

“This is the fastest growing Ebola outbreak ever, not only among the previous Bundibugyo outbreaks, but all the different viruses that are causing Ebola,” Wessam Mankoula, head of emergency preparedness and response for the Africa Centres for Disease Control and Prevention (Africa CDC) told reporters.

The deadliest Ebola outbreak — in 2013-16 in West Africa — had 994 cases in the first six weeks, compared to 1,596 in the current one, he said.

“Unfortunately, the virus is still ahead of our response. It’s moving faster than deploying the resources to control the situation,” Mankoula said, adding that the number of cases was estimated to be doubling every 28 days.

He said $1.4 billion was needed in total for the disease and humanitarian response.

“We need to surge our response, and surging our response means financial resources, human resources,” Wessam said. “We are urging all partners, donors… to fast-track the disbursement of those resources.”

Ebola spreads through close contact and infected bodily fluids. The current outbreak is caused by Bundibugyo, a rare species that has no approved vaccine or treatment and is believed to have spread for some time before it was detected.

The WHO’s figures for the DRC, which come from the health authorities in the vast country, show that the outbreak there has a case fatality rate of 34 per cent.

A total of 285 patients in the DRC have recovered, while 304 suspected cases of the viral haemorrhagic fever are under investigation.

The outbreak in northeastern DRC has hit four provinces but is focused on Ituri province.

The trial of two potential treatments for Bundibugyo began in the DRC on July 2, and is evaluating the effectiveness of the monoclonal antibody MBP134 and the antiviral drug remdesivir, alone and in combination.

The DRC’s 17th Ebola outbreak was declared on May 15 after several deaths in Ituri, a mineral-rich province plagued by armed groups.

“Population movements, persistent insecurity, and the fragility of the health system continue to complicate efforts to bring the outbreak under control,” Anne Ancia, the WHO’s representative in the DRC, said Tuesday.

She said there were now around 700 beds across 22 treatment centres and 300 more beds in the pipeline, with centres operating at around 90 per cent capacity.

More than 10,000 contacts of infected people are being monitored, at a follow-up rate of 82 per cent. The WHO believes a rate of 95 per cent is needed to get on top of the outbreak.

Laboratory capacity has increased from 30 tests per day in the capital Kinshasa to more than 2,000 in decentralised labs in the affected provinces.

One of the affected provinces is South Kivu, which has seen clashes between the Congolese armed forces and the Rwanda-backed M23 armed group.

“Before Ebola struck, millions were already facing conflict, hunger, displacement, weak basic services and limited healthcare,” Tom Fletcher, head of the UN’s humanitarian operations, said in a communique.

“DRC is one of the world’s most complex humanitarian crises. Recent cuts in humanitarian funding have made the response even harder,” he said.