The World Health Organization (WHO) said there are now 321 confirmed cases of Ebola and 116 suspected cases in the ongoing outbreak. The sharp reduction in suspected cases follows a large-scale review of alerts and patient records, during which many individuals initially flagged as possible Ebola infections were found not to have the virus.
The agency also reported 48 deaths and six recoveries as of 2 June, with national authorities releasing the updated figures earlier in the week.
A WHO spokesperson, Christian Lindmeier, explained that the apparent drop does not necessarily reflect a sudden improvement in the outbreak itself, but rather improved classification of cases.
“They have been cleared out and have either other diseases or have just had fever and nothing else,” he said. Lindmeier added that “the numbers would fluctuate over time as people get tested.”
He clarified that suspected cases include anyone identified through surveillance systems or presenting at health facilities with Ebola-like symptoms, while confirmed cases are strictly those that test positive for the Bundibugyo strain.
Cross-Border Spread and Rising Case Counts in Uganda
In neighbouring Uganda, health authorities are also tracking infections linked to the outbreak.
WHO spokesperson Christian Lindmeier said Uganda had recorded nine confirmed cases and one associated death. However, the Ugandan Ministry of Health later reported an increase, confirming six additional cases on Tuesday. This brings the country’s total to 15 confirmed infections.
The ministry stated in a post on its official X account that the new cases were identified among contacts of previously confirmed patients, underscoring ongoing community transmission and active contact tracing efforts.
Conflicting Suspected Case Numbers Highlight Surveillance Challenges
Data on suspected cases has varied across agencies and reporting periods, reflecting the difficulty of tracking a rapidly evolving outbreak in areas with limited testing capacity.
The WHO reported 906 suspected cases of the Bundibugyo Ebola virus in Congo, including 223 suspected deaths under investigation. However, Jean Kaseya, director-general of the Africa Centres for Disease Control and Prevention, later wrote in a Financial Times op-ed that more than 1,100 suspected cases were under review.
Health officials say such fluctuations are expected as investigations progress and testing results come in from different regions and facilities.
The U.S. Centers for Disease Control and Prevention also reported 116 suspected cases, noting that Congolese health authorities had recently removed individuals from the suspect list after they were ruled out or were still awaiting investigation outcomes.
According to the CDC, “On 29 May, the DRC Ministry of Health updated their total suspect case count to remove suspected cases that have been ruled out after investigation and suspected deaths that are pending the results of ongoing investigation.”
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| Congolese health workers who recovered from the Ebola virus pose for a photograph at the Evangelical Medical Center (CEM), as agencies intensify efforts to contain a new Ebola outbreak caused by the Bundibugyo virus strain, in Bunia, Ituri province, Democratic Republic of Congo, 31 May 2026. REUTERS/Gradel Muyisa Mumbere |
Officials say the reduction in suspected cases reflects improved diagnostic clarity rather than a collapse in surveillance.
A suspected case typically includes anyone flagged through community surveillance systems or patients presenting with Ebola-like symptoms such as fever, vomiting, or unexplained bleeding. These cases are later tested to confirm whether Ebola infection is present.
Many of those initially classified as suspected cases were ultimately found to have other illnesses or non-Ebola fevers once laboratory testing and follow-up investigations were completed.
“They have been cleared out and have either other diseases or have just had fever and nothing else,” Lindmeier said.
Diagnostic Gaps and Strain-Specific Challenges
The current outbreak, caused by the rare Bundibugyo strain of Ebola, has highlighted persistent challenges in diagnostic capacity.
Early in the outbreak, standard Ebola tests did not reliably detect this strain, contributing to delays in identification and case confirmation. Health systems in affected regions have also faced shortages in laboratory infrastructure, trained personnel, and rapid testing kits.
Unlike more widely known Ebola strains, Bundibugyo currently has no approved vaccine, limiting prevention efforts and placing greater emphasis on surveillance, isolation, and supportive care.
Outbreak Declared a Global Health Emergency
The Bundibugyo Ebola outbreak was officially declared on 15 May, marking Congo’s 17th recorded Ebola outbreak.
The World Health Organization subsequently classified it as a Public Health Emergency of International Concern, triggering increased international coordination, funding mobilization, and cross-border response mechanisms.
Despite these measures, officials warn that the situation remains fluid, with case counts expected to continue changing as investigations advance and testing results are updated across affected regions.