The Centers for Disease Control and Prevention (CDC) has released a Health Alert Network (HAN) Health Advisory regarding a significant outbreak of Ebola virus disease (EVD) in the Democratic Republic of the Congo (DRC). EVD is a severe and often fatal illness, and while the outbreak is concerning, the CDC reports that no suspected, probable, or confirmed cases related to this outbreak have been identified in the United States or outside the DRC. Currently, the risk of EVD spreading to the United States is considered low.
As a precautionary measure, the CDC has outlined recommendations for U.S. public health departments, clinical laboratories, and healthcare workers regarding potential EVD case identification, testing, and biosafety in clinical settings. On September 8, 2025, the CDC issued a Travel Health Notice advising all travelers to the affected health zones in DRC to avoid contact with ill individuals. Travelers are also urged to monitor themselves for symptoms of EVD during their stay and for 21 days following their departure from the outbreak area. Should travelers develop symptoms during this 21-day period, they should self-isolate and contact local health authorities or a clinician immediately.
The outbreak was officially declared by the DRC's Ministry of Public Health, Hygiene and Prevention on September 4, 2025, following the re-emergence of the Ebola virus (species Orthoebolavirus zairense) in the Kasai Province. As of September 18, there have been 37 confirmed cases and 19 deaths, including four healthcare workers, leading to a case fatality rate (CFR) of 51%. This marks the 16th recorded Ebola outbreak in the DRC since the virus was first identified in 1976. The Kasai Province has a history of EVD outbreaks, including two significant events in 2007 and 2008.
The current outbreak is primarily centered in the Bulape and Mweka health zones of the Kasai Province. The index case was identified as a 34-year-old pregnant woman who was admitted to a local hospital on August 20, 2025, displaying symptoms such as high fever, bloody diarrhea, and severe physical weakness. Unfortunately, she passed away on August 25 due to multiple organ failure. Following her case, two healthcare workers who treated her also exhibited similar symptoms and succumbed to the disease.
The CDC is actively collaborating with the DRC's Ministry of Public Health to address this outbreak. In an effort to strengthen response measures, the CDC has deployed five experts to provide technical assistance in areas such as surveillance, case investigation, and contact tracing. Resources are also being allocated to enhance laboratory testing and infection control measures. While the source of the outbreak remains unidentified, additional cases may be identified as investigations continue.
Despite the current situation, the risk of EVD spreading to the U.S. is low due to limited access to the outbreak region and the absence of direct flights between the DRC and the United States. However, travelers from the affected areas may enter the U.S. via connecting flights. In light of this, the CDC is working to raise awareness of the outbreak among travelers and healthcare professionals in the United States. It is crucial for healthcare providers to remain vigilant and evaluate any patients with a travel history to affected regions.
Ebola disease is caused by a group of viruses known as orthoebolaviruses, which primarily affect humans and nonhuman primates. Among the four orthoebolaviruses, the Ebola virus (species Orthoebolavirus zairense) is responsible for EVD. The incubation period for EVD ranges from 2 to 21 days following exposure, and individuals are not considered contagious until symptoms appear. Initial symptoms include fever, aches, and fatigue, which can progress to more severe symptoms such as diarrhea, vomiting, and unexplained bleeding.
EVD is transmitted through direct contact with body fluids of infected individuals or animals, and it is not spread through airborne transmission. The U.S. Food and Drug Administration (FDA) has approved an Ebola vaccine, ERVEBO®, for preventing EVD due to the Ebola virus, with specific criteria for administration. Additionally, two FDA-approved treatments, Inmazeb™ and Ebanga™, are available for managing Ebola virus infections. Without early diagnosis and appropriate treatment, EVD can result in high fatality rates, historically ranging from 80% to 90% during outbreaks.
The CDC has developed guidelines for U.S.-based organizations, including non-governmental and academic entities, with personnel operating in regions affected by viral hemorrhagic fever (VHF) outbreaks. It is essential for these organizations to implement safety measures and ensure their staff is well-informed about EVD and its risks. By following these recommendations, organizations can help mitigate the potential impact of EVD and contribute to global health security.
