Microscopic view of the Ebola virus
(Adobe Stock 323887739 by Monika Wisniewska)
The CDC issued a Health Alert Network (HAN) advisory following confirmation of a new outbreak of Ebola virus disease (EVD) in the Democratic Republic of the Congo (DRC) on September 18, 2025. The update on September 19 said there are no cases of Ebola from this outbreak in the US. However, the advisory emphasizes vigilance among public health departments, clinical laboratories, and frontline health care workers.
Yesterday, the World Health Organization (WHO) posted, “As of 21 September 2025, a total of 57 cases (47 confirmed and 10 probable cases), including 35 deaths (25 confirmed and 10 probable) (overall case fatality ratio 61.4%) have been reported from Bulape Health Zone, Kasai Province, Democratic Republic of the Congo. There are five confirmed cases among health workers. Cases range from zero to 65 years old, with age group 0 – 9 years the most affected, accounting for 23% of the total cases. Females account for 61% of cases. Case fatality ratio among females is 56% compared to 73% among males. Children, housekeepers and farmers are the most affected groups.”
The WHO announcement also stated that as of September 21, 2025, 1,180 contacts have been identified, with 94 having completed 21 days of monitoring. Since the outbreak, 26 cases have been admitted; 2 were treated and discharged by September 16, five have died, and 19 remain in treatment as of September 21.
Background on the Outbreak
On September 4, 2025, the DRC’s Ministry of Public Health, Hygiene, and Prevention declared an outbreak in Kasai Province, marking the country’s 16th outbreak since Ebola was first identified there in 1976. As of September 18, health officials have reported 37 confirmed cases and 19 deaths, including four health care workers, for a case fatality rate of 51%.
The index case was a 34-year-old pregnant woman admitted with fever, bloody diarrhea, hemorrhage, vomiting, and severe weakness. She died on August 25, and 2 health care workers who treated her also succumbed to the disease. Laboratory analysis confirmed Ebola virus (species Orthoebolavirus zairense) as the cause. “Genomic sequencing performed by INRB suggests that this is a new introduction of the disease into the human population from an unknown infected animal,” CDC noted in its advisory.
Travel Health Notice and Risk to the US
On September 8, CDC issued a Travel Health Notice for travelers to the affected health zones, urging them to avoid contact with ill people and monitor themselves for symptoms during travel and for 21 days after leaving the region.
Currently, the risk of spread to the US is considered low. “There are no direct flights between the DRC and the United States,” CDC reported. However, travelers may arrive through connecting flights, and as a precaution, clinicians are urged to obtain a thorough travel history when evaluating patients with compatible symptoms.
Recommendations for Clinicians
CDC is reminding US clinicians that early “dry” symptoms of EVD, such as fever, aches, and fatigue, can rapidly progress to “wet” symptoms, including diarrhea, vomiting, and unexplained bleeding.
“Health care providers should be alert and evaluate any patients suspected of having EVD,” the advisory stressed. Providers should:
- Isolate and hospitalize any patient with compatible symptoms and risk factors until EVD can be ruled out.
- Obtain specimens for testing at 72 hours or later after symptom onset, while also evaluating for more common causes such as malaria, COVID-19, and influenza.
- Use appropriate personal protective equipment (PPE) and follow infection prevention protocols while test results are pending.
If EVD is confirmed, patients should be transferred to a Regional Emerging Special Pathogens Treatment Center or a state-designated facility.
Public Health and Laboratory Guidance
CDC urged public health departments to coordinate with local jurisdictions, the CDC Viral Special Pathogens Branch, and designated laboratories for suspected cases. The Laboratory Response Network has 42 labs across the US capable of performing presumptive Ebola testing, with confirmatory results provided by the CDC.
Laboratories are instructed to treat all specimens as potentially infectious and to have written exposure control plans, PPE training, and risk mitigation protocols in place.
Global and Local Preparedness
Although vaccines and therapeutics are available, including ERVEBO for prevention and Inmazeb and Ebanga for treatment, CDC emphasized that early detection, strict adherence to infection control measures, and international collaboration remain the cornerstones of response.
“Early consideration of EVD in the differential diagnosis is important for providing appropriate and prompt patient care and diagnostics, and to prevent the spread of infection,” CDC emphasized.
The WHO announcement also stated that “WHO has launched an appeal of US$21 million to support the Democratic Republic of the Congo to scale up response operations to interrupt all transmission chains, control the outbreak, and mitigate the impact on human health. So far,US$2 million has been released from WHO’s Contingency Fund for Emergencies to finance immediate response activities.”
Conclusion
While the current Ebola outbreak in the DRC poses little immediate threat to the US, the CDC and WHO’s advisory underscores the importance of vigilance. For infection preventionists and clinicians, the message is clear: Maintain awareness, reinforce travel history screening, and be prepared to act swiftly if a suspected case arises.