At least 30 people have died since the start of May in one camp for displaced civilians in northeastern Congo, a death rate that camp officials said was unprecedented, and, because of the symptoms, could indicate Ebola is spreading fast there.

It was not possible to confirm the causes of death because patients or their relatives in Kigonze camp in Bunia - the epicentre of the Ebola outbreak in Democratic Republic of Congo - had until Thursday refused testing the living or dead, a camp spokesperson and aid organisation Caritas said.

However, all had symptoms including headaches, fever and vomiting, which are associated with Ebola, a camp spokesperson, a bereaved father, three aid sources and a civil society leader told Reuters.

"People didn't just die like this before," camp spokesperson Desire Grodya Bapi told Reuters.

The deaths in Kigonze, which has more than 15,000 residents, raise fears that Ebola may be circulating undetected among eastern Congo's over five million displaced people, with resistance to testing compounding the challenge posed by severely limited sanitation measures.

Camp President Dz'djo Ndrutsi Etienne said 10 people were buried this week alone. Grodya said the camp typically recorded between one and three deaths per month.

Footage from Thursday shared by the civil society leader and verified by Reuters showed health teams in hazmat suits at the Kigonze camp disinfecting more bodies and preparing tiny coffins next to a crucifix as mourners wailed.

"Our team tried to persuade people to accept doctors to inspect the bodies. They completely refused," Zanamuzi said.

A senior World Health Organization official said on Friday that 75 medics in the Democratic Republic of Congo had been infected with Ebola and 17 of them had died since the current outbreak started there.

Ebola was thought to be circulating months before the outbreak was first declared by Congolese officials on May 15, meaning many medics were exposed to the disease before they even knew it was present. Even now, health officials say supplies of the basic gear to protect themselves like gloves and masks are running short.

"It is a really high price that the system, the healthcare system, is paying, because we don't have enough of healthcare workers in DRC," a WHO emergency director, Marie Roseline Belizaire, told a press conference by video link from eastern Democratic Republic of Congo.

Four aid workers said the spike in deaths highlighted how communities were now more exposed to diseases such as Ebola as donors, including key contributor the US under President Donald Trump, have cut funding for water, hygiene and sanitation, which is essential in fighting a disease that spreads through bodily fluids such as human waste.

Data compiled by the UN showed that funding for toilets and handwashing stations in Congo more than halved between 2024 and 2025, to around $US38 ($A54) million, and this year's $US80 million ($A114 million) appeal is only 21 per cent funded.

Congo has hundreds of camps for civilians fleeing war, some home to 100,000 people. Ebola deaths have already been recorded in another camp in the same province of Ituri, which has over 90 per cent of nearly 900 confirmed cases.

In Kigonze, large families share the same plastic tent spaced less than a metre apart and children wander its dirt alleyways barefoot.

There are toilets marked USAID - Washington's international aid agency dismantled by Trump - and an aid source said the agency helped fund their construction.

However, Grodya and the aid source said there were not enough toilets and they often overflowed.

"The latrines, they fill up very quickly, and people have to empty them themselves, with their bare hands," Grodya said.