BUNIA, Congo -- The number of confirmed cases of Ebola virus in Congo has surged past 8,000, as the country runs out of health workers to contain the deadly disease.

Congo announced an outbreak on May 15, caused by the rare Bundibugyo virus, which has no known treatment or vaccine, and has struggled to contain it.

The latest data from Congo's health ministry released Sunday showed that 8,067 cases have been confirmed, with 3,901 deaths as of Sept. 26 across 63 health zones in seven of the country's 26 provinces, with a fatality rate of more than 48%.

“The continuously high crude case fatality ratio, and especially the continuously high rate of deaths occurring in communities, highlights the seriousness of the disease and the persistent challenges in timely case detection and access to early and adequate patient care,” the World Health Organization said in its latest report.

It means that a large percentage of those infected were dying, without taking into account factors like delays in seeking help or hidden cases.

The U.N. Office for the Coordination of Humanitarian Affairs said on Monday that the outbreak has begun to have an impact on other essential services in the hot spots as resources are mobilized toward fighting Ebola. According to OCHA's report, routine primary healthcare services fell by 13% between April and June in Ituri province alone.

“The indirect impact of the outbreak reflects both reduced health service availability — as a result of staffing and operational pressures — and reduced demand, as fear of infection and isolation discourages care-seeking,” OCHA said.

Last week, WHO said that Congo was running out of health workers to contain the disease. Health workers have complained about delayed or missing payments, triggering several strikes. According to the Africa Centers for Disease Control and Prevention, 50 health workers have died since the outbreak was announced.

Some areas have shown signs of improvement, with fewer confirmed cases in the past several weeks, including in Ituri province and Haut-Uele, but officials say the disease is spreading further in other areas, expanding its geographical reach.

According to data from the Africa CDC, the current outbreak has outpaced the two-year West Africa regional outbreak in terms of spread in the same time. By week 19, the regional outbreak between 2014 and 2016 recorded 3,781 cases, while the current outbreak recorded 7,840. WHO said that it's on track to surpass the regional outbreak, which killed 11,000 people.

Containment efforts have been hamstrung by insecurity, displacement, a health workers’ strike and intense population movements.