KINSHASA, June 12 (Xinhua) -- The Ebola outbreak in the Democratic Republic of the Congo (DRC) has continued to expand, with health authorities reporting 676 confirmed cases, including 136 deaths, as weak contact tracing, insecurity and funding gaps undermine efforts to contain the disease.
According to the latest situation report released Thursday by the DRC's health authorities, 41 new confirmed cases, including nine deaths, were reported on Wednesday.
The outbreak has now affected 29 health zones across three eastern provinces, namely Ituri, North Kivu and South Kivu.
The number of confirmed cases has continued to increase from week to week, indicating ongoing community transmission. A sudden geographic expansion of the outbreak is feared if public health measures are not implemented quickly, the report said.
RAPID SPREAD, WEAK CONTACT TRACING
Jean Kaseya, director-general of the Africa Centers for Disease Control and Prevention, told an online press briefing Thursday that the outbreak's geographic spread and weak contact tracing were now among the main indicators guiding the response.
"When the outbreak was declared on 15th of May, we had three health zones (reporting cases)," Kaseya said.
The outbreak later spread to three provinces and the number of affected health zones rose from 14 to 27 in about 10 days. "It means we are doubling the number of health zones affected in 10 days," he said.
Contact tracing remained far below what was needed, especially in Ituri, Kaseya said.
With about 600 confirmed cases in the province, health authorities would expect about 24,000 contacts to be listed, based on an estimate of about 40 contacts for each confirmed case, but about 5000 contacts had been listed, and only a limited share of those were under active follow-up, he said.
"If we don't know these people, if we don't have them on the list, if we don't follow up, it means there is a huge risk of transmission to be sustained in the community," Kaseya said.
Some confirmed cases had not been admitted for treatment and remained outside health facilities, he said. "We cannot say we can control this outbreak very soon."
Kaseya said the current outbreak had already surpassed the burden of the two previously known outbreaks caused by the Bundibugyo Ebola virus, a rarer type of the Ebola pathogen that has no approved vaccine nor treatment.
The caseload of the current outbreak was nearly five times the size of the 2007 outbreak in Uganda and 17 times that of the 2012 outbreak in the DRC, he said.
In terms of confirmed cases, Kaseya said, the current outbreak is already the third-largest Ebola outbreak among 20 historical Ebola outbreaks recorded in Africa.
WHO KEEPS DRC RISK AT "VERY HIGH"
The current outbreak is the country's 17th Ebola outbreak since 1976 and the second in the DRC caused by the Bundibugyo virus.
In a rapid risk assessment dated June 6, the World Health Organization (WHO) assessed the risk in the DRC as "very high," citing ongoing transmission, rapid growth in cases, geographic expansion and the risk of further national and regional spread.
The WHO said that between May 22 and June 6, confirmed cases in the DRC increased more than eightfold, from 63 to 515, while the number of health zones with confirmed cases rose from 16 to 25.
Retrospective investigations identified suspected viral hemorrhagic fever cases dating back to March, suggesting that the virus may have circulated undetected for weeks before the outbreak was confirmed in May, the WHO noted.
It said diagnostic tests not validated for the Bundibugyo virus may have contributed to missed early cases, allowing transmission to continue in communities and health facilities before response measures were fully launched.
The WHO also warned of likely under-reporting of cases, low contact-tracing coverage, limited laboratory diagnostic capacity, insufficient isolation infrastructure and community mistrust of response measures.
At least 16 health workers in the DRC were among confirmed cases, the WHO said, pointing to the risk of transmission in healthcare settings and gaps in infection prevention and control.
Describing Bundibugyo virus disease as a severe viral hemorrhagic disease, the WHO assessment kept the current risk in the DRC at "very high."
UGANDA UNDER CONTROL
Uganda, which has reported cases linked to the DRC outbreak, remains under close watch.
The WHO assessed the risk in Uganda as "high" but said all reported cases there had been linked to importation from the DRC or secondary cases connected to those imported cases, with no documented community transmission.
Kaseya said Uganda's outbreak was "really under control," based on the figures available to Africa CDC.
Confirmed cases there had come from contact lists, indicating that there was no evidence of community transmission, he said.
Meanwhile, the WHO has assessed the risk for countries sharing land borders with countries where Bundibugyo virus has been detected as high, while the risk for the rest of the African region and the global level remains low.
It said no evidence currently suggests sustained international transmission beyond the DRC and Uganda border areas, although exportation of cases through international travel remains possible.
Kaseya also warned that Africa is facing multiple health emergencies at the same time, with cholera outbreaks ongoing in 15 African countries, while measles and mpox remain public health concerns.
For measles, he said, the trend from the first to the 22nd week of 2026 was close to that of 2024 and higher than that in 2025.
In the DRC, Kaseya said, North Kivu and South Kivu were among the main drivers of measles, with low vaccination coverage in areas also affected by insecurity.
The weekly number of mpox cases and deaths was declining, showing progress in the response, the Africa CDC chief said.
The latest Ebola outbreak is unfolding in some of the DRC's most unstable provinces.
Ongoing conflict in Ituri and North Kivu restricts the movement of surveillance teams, limits the deployment of rapid response teams, hinders the secure transport of laboratory samples and complicates contact tracing and safe burials, the WHO said.
Kaseya stressed the importance of security access in eastern DRC, calling for a ceasefire to allow health workers to reach communities. "We cannot respond to this outbreak when we are facing insecurity." ■