The fastest-growing Ebola outbreak in history has killed more than 1,000 people in eastern Congo, as health officials work to contain a virus that currently has no approved vaccine or treatment.
According to an update from Congo’s public health institute, there have been 2,536 confirmed Ebola cases and 1,033 deaths. At least 738 patients are in isolation or hospitalized. The outbreak, declared on May 15, is characterized by the Bundibugyo virus, which differs from most previous Ebola instances due to the lack of approved vaccines or treatments.
The outbreak is primarily concentrated in the remote Ituri province, which accounts for nearly 90% of cases. However, cases have also been confirmed in five other provinces, including Kisangani, one of Congo’s largest cities, and in neighboring Uganda.
Congolese officials suggest the sharp rise in cases may be slowing, but they caution that the outbreak has not yet peaked. The country's public health institute reports sustained transmission, with recent fluctuations attributed to reporting delays and data consolidation.
Contact tracing efforts are lagging, with only around 77% of known contacts being monitored nationwide, falling short of the 95% target necessary to interrupt transmission. Researchers from the U.S. Centers for Disease Control and Prevention have utilized computer modeling, indicating a worst-case scenario could approach the severity of history's worst Ebola outbreaks. For comparison, the West Africa epidemic from 2014-2016 resulted in over 11,000 deaths and took approximately eight months to reach 1,000 deaths.
The origin of the current outbreak remains a medical mystery, with the World Health Organization (WHO) noting that the majority of cases stem from unknown transmission chains. The WHO assesses the risk as "very high" within Congo and "high" in Uganda and neighboring countries due to cross-border spread, population movement, and ongoing transmission in eastern Congo. The global risk of spread is considered low, as Ebola transmits through direct contact with bodily fluids rather than airborne means, making it less likely to spread rapidly compared to respiratory viruses. The WHO anticipates additional imported cases as the outbreak grows but notes that these have been rapidly detected and contained, preventing sustained transmission outside the affected regions.
Ebola does not spread like respiratory viruses such as the flu or COVID-19, according to the CDC. The agency clarifies that individuals infected with Ebola are not contagious until they develop symptoms, which aids in case identification and contact tracing.
In Uganda, 20 cases have been confirmed, including two deaths, all linked to infections imported from Congo. These cases are concentrated in the capital, Kampala. No new cases have been reported in Uganda since June 21, and the WHO has discharged its final patient, initiating the 42-day countdown to potentially declare the outbreak's end.
A doctor traveling from Congo was diagnosed with Ebola in France in June and has since recovered. The United States currently restricts entry for most recent travelers from Congo and requires U.S. citizens to spend 21 days outside Congo before returning. Travelers from neighboring Uganda and South Sudan who are permitted entry are routed through designated airports for Ebola screening.
Plans for a U.S.-funded Ebola quarantine facility in Kenya for Americans evacuated from Congo have faced legal challenges and protests, some of which have turned violent. Authorities and health workers identify a lack of trust and local resistance as significant obstacles to containing the outbreak. Rumors about treatment centers, fears of isolation, and opposition to safe burial practices have led some individuals to avoid testing or seek care only when critically ill.
The response has also been complicated by ongoing conflict, including fighting involving the Rwanda-backed M23 rebels, attacks by the Islamic State-linked Allied Democratic Forces, and mass displacement, all of which have hampered surveillance, contact tracing, and access to affected communities.
Clinical trials for potential treatments for the Bundibugyo virus began earlier this month, enrolling patients at an Ebola treatment center in Ituri province. The WHO estimates that it could take months and up to 1,000 participants to determine the effectiveness of the two experimental treatments.