GENEVA — The outbreak of a deadly strain of Ebola for which there is no vaccine is accelerating through the Democratic Republic of Congo (DRC) and Uganda at a “scale and speed” alarming the World Health Organization (WHO), as cases climb and authorities scramble to contain the spread.

“I’m deeply concerned about the scale and speed of the epidemic,” WHO chief Dr Tedros Adhanom Ghebreyesus told the 79th World Health Assembly on Tuesday, addressing delegates from 192 nations gathered in Geneva.

More than 500 suspected cases and 130 suspected deaths beyond the confirmed caseload have been reported. Tedros said the figures would change as field operations scale up, including strengthening surveillance, contact tracing, and laboratory testing.

“So far, 30 cases have been confirmed in the DRC from the northern province of Ituri,” he added. “Uganda has also informed WHO of two confirmed cases in the capital of Kampala, including one death among two individuals who travelled from DRC, and there is one US citizen confirmed positive and transferred to Germany.”

“This epidemic is caused by Bundibugyo, a species of Ebola virus for which there are no vaccines or therapeutics,” Tedros said.

Diagnostic tests in the region were designed for a different strain of Ebola and missed early infections, resulting in a four-week gap before the outbreak was detected. Ongoing shortages of diagnostic equipment on the frontlines mean the true size of the outbreak remains unknown.

“In the absence of a vaccine, there are many other measures countries, of course, can take to stop the spread of this virus and save lives, even without medical countermeasures, including risk communication and community engagement,” Tedros said, commending Uganda for postponing its annual Martyrs’ Day celebrations, which can draw up to two million people.

The Ebola virus kills up to half of those it infects, making any outbreak particularly dangerous.

In response to the outbreak, the United States banned citizens from the DRC, Uganda and Sudan from entering the US on Monday.

Also read: Tedros: ‘We Live in Difficult, Dangerous and Divisive Times’

‘Did not do this lightly’

The rapid spiral led Tedros to declare the outbreak a public health emergency of international concern (PHEIC) on Sunday, the first time a Director-General has done so before convening an emergency committee.

“I did not do this lightly,” he told the assembly. “I did it in accordance with Article 12 of the International Health Regulations, after consulting the ministers of health of both countries.”

The emergency committee will meet later on Tuesday to advise on what response measures countries should adopt, as there is no vaccine and no cure for the strain of Ebola now spreading.

The first confirmed case was a health worker, meaning the virus was already moving through medical settings before anyone knew it was there.

After heavy criticism of the WHO’s slow handling of the 2014 West African Ebola epidemic, the agency’s chief appears unwilling to allow a repeat of history. Tedros said an additional $3.4 million was released from the WHO’s Contingency Fund for Emergencies, bringing the total committed to the response to $3.9 million.

“WHO has a team on the ground supporting national authorities to respond,” he said. “We have deployed people, supplies, equipment, and funds.”

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Deadly delays leave authorities flying blind

Cases have surfaced in densely populated urban areas, including the Ugandan capital Kampala and the eastern DRC city of Goma, home to millions of people and serving as major hubs for cross-border trade and movement.

The outbreak is likely to have originated in DRC’s Ituri province, a high-traffic mining area on the borders of South Sudan and Uganda, which “increases the risk of regional exportation and cross-border transmission”, according to the WHO.

Fighting in the area between the DRC army and M23, an Islamist armed group, has intensified since late 2025 and escalated significantly over the past two months.

More than 100,000 people have been newly displaced by the conflict, Tedros told the assembly – potentially carrying the virus with them as they go, far from the reach of surveillance teams and into communities with little capacity to identify or isolate new cases.

“In Ebola outbreaks, you know what displacement means,” Tedros said. “The area is also a mining zone with high levels of population movement that increase the risk of further spread.”

Local funeral practices, which involve close contact and touching the deceased, also accelerated transmission before authorities knew the outbreak was happening.

The current outbreak is the third recorded outbreak of Bundibugyo, first identified in 2007.

Hantavirus contained 

The picture is markedly different for hantavirus, which Tedros also addressed.

Two weeks ago, the hantavirus outbreak aboard the MV Hondius cruise ship, sparked international panic and wall-to-wall news coverage, but it has now been brought under control, Tedros told the assembly.

“WHO’s assessment continues to be that the risk of hantavirus globally is low,” Tedros said. 

The ship docked in Rotterdam on Sunday, with the crew now in quarantine until 29 June. Passengers, who have been repatriated, will be monitored until 21 June.

“So far, there are 11 reported cases, including three deaths, and no deaths have been reported since the second of May, when WHO was first informed of the outbreak on the ship. Those numbers have changed little since the outbreak was first reported to WHO two weeks ago,” Tedros said. 

The two outbreaks, emerging within two weeks of each other, served as a reminder of WHO’s core function, Tedros told the assembly.

“The outbreaks of Ebola and Hantavirus in the past two weeks show why international threats need an international response,” he said. “They show why the world needs the international health regulations and why it needs WHO.”

WHO successes: tobacco and taxes

Tedros also highlighted WHO’s wins in his address, including the decline in tobacco use.

“Tobacco use has dropped by one-third globally and continues to decline in 140 countries. With support from WHO, Maldives became the first country to adopt a generational tobacco ban for people born from 2007. This year, the United Kingdom followed suit, banning the sale of tobacco to anyone born from 2009 onwards,” he said.

Since 2025, the WHO has been encouraging countries to tax tobacco, alcohol, and sugary drinks by at least 50% by 2035.

“In the past 12 months, India, Jamaica, Malaysia, Mauritius, Mexico, Montenegro, Viet Nam, Saudi Arabia, Sierra Leone and Zambia were among countries that either announced, introduced or increased taxes on one or more of these products,” Tedros said.

WHO’s advocacy to increase the rate of breastfeeding globally has also yielded positive results, with almost half of children worldwide being breastfed for at least for six months, Tedros said. 

A billion more people now have access to safe drinking water compared to just a decade ago, but the levels of violence against women have remained stagnant for two decades.

However, the shortage of healthcare workers is hampering progress: “The world is facing a shortage of 11 million health workers by 2030, with the biggest gaps in the African and Eastern Mediterranean regions. More than half the gap is a shortage of nurses,” Tedros said.

The world is also set to miss every one of the 52 health-related Sustainable Development Goal targets by 2030, the WHO revealed on the eve of the WHA.

Malaria cases are rising, maternal deaths are still occurring at nearly three times the targeted rate and childhood vaccination coverage is plateauing or falling in some regions, and progress on global health goals has slowed, stalled or reversed across virtually every measure since 2015, according to the 2026 World Health Statistics report.

Image Credits: WHO/Christopher Black , WHO/X, Africa CDC , WHO/X.