Uganda's Ebola outbreak officially ended Thursday, 42 days after the country's last confirmed patient was discharged from care on July 16, the World Health Organization confirmed — the same day the U.S. Centers for Disease Control and Prevention said the Democratic Republic of Congo's ongoing outbreak had become the second-largest Ebola outbreak ever recorded. [1] The pairing lands almost exactly on schedule: this paper reported August 1 that Uganda's July 28 declaration was preliminary, made before the WHO's 42-day surveillance window had actually closed. Thursday's announcement is that formal epidemiological certification, arriving 26 days later than the political one.

Uganda's final tally was small and largely imported: 20 confirmed cases and two deaths, with 15 of the 20 either brought in directly from the Democratic Republic of Congo or linked to transmission chains originating there. [1] Five cases were locally acquired among contacts and health care workers, and Uganda's response monitored more than 800 contacts since May 15. [1] WHO director-general Tedros Adhanom Ghebreyesus credited the outcome to preparedness rather than luck. "Uganda has demonstrated that with decisive action, Ebola outbreaks can be brought under control quickly," he said, citing increased surveillance and careful management of points of entry. [1] Africa CDC director-general Jean Kaseya framed the closure as a model with an explicit warning attached: "This is a victory for Uganda and an important lesson for our continent. We must now protect this achievement while accelerating the response in the DRC. We will only be secure when transmission is stopped everywhere." [1]

That warning is doing real work, because the DRC side of the same announcement describes an outbreak still accelerating past historic benchmarks. The CDC's Wednesday update put the Bundibugyo-strain outbreak at 5,656 confirmed cases and 2,715 deaths, calling it "the second-largest Ebola outbreak on record" and noting it surpassed 1,000 confirmed cases within 40 days of response efforts activating, against roughly 235 days for the country's 2018 outbreak to reach the same threshold. [1] Those figures differ from the 5,794 cases and 2,786 deaths this paper reported Wednesday from the World Health Organization's own Disease Outbreak News bulletin — a gap of more than 100 cases and 70 deaths between two health authorities describing the same outbreak on the same week. Neither figure is obviously wrong; WHO's and CDC's counts run on different reporting cycles and compile from different upstream sources, and a modest downward shift in a fast-moving, unevenly reported outbreak is more likely a reporting-lag artifact than a genuine decline. But the discrepancy is real, and it means neither number should be treated as a settled final count. BBC's own separate reporting adds a third data point rather than resolving the other two: 5,514 cases and 2,642 deaths as of August 23, with a case-fatality rate of roughly 48 percent. [2]

The superlatives attached to each figure are also doing different work than they first appear to. Wednesday's WHO-sourced figure led this paper to describe the outbreak as the deadliest in the Democratic Republic of Congo's own history, surpassing the country's 2018-2020 epidemic's 3,317 cases. Thursday's CDC-sourced figure describes it instead as the second-largest ever recorded globally, behind only the 2014-16 West African epidemic's 28,715 cases. [2] Both claims can be true simultaneously — one is a national comparison, the other a global one — but neither WHO's nor the CDC's framing surfaces that distinction explicitly, leaving readers to reconcile two different superlatives about the same outbreak without being told they're measuring different things.

The strain driving both numbers remains the deeper reason for caution regardless of which count is used. Bundibugyo virus disease, a distinct Ebola species from the more common Zaire strain, has historically killed roughly a third of those infected — far below Zaire's 66.6 percent fatality rate or Sudan strain's 48.5 percent — yet the current outbreak's case-fatality ratio sits near 48 percent, elevated well above the species' historical pattern. [2] No vaccine or antiviral treatment is licensed specifically for Bundibugyo virus disease. DRC has begun vaccinating health workers with Ervebo, the vaccine developed against the Zaire strain, inside a randomized clinical trial designed to generate evidence on whether it offers meaningful protection against this outbreak's actual strain — evidence that does not yet exist. [2] Against that gap, CEPI announced Thursday it is partnering with Egypt's Minapharm Group to advance a fifth Bundibugyo-specific vaccine candidate, built on the same modified-vaccinia-Ankara platform that underpins the licensed mpox and smallpox vaccine. "In just three months, cases of Bundibugyo have spread rapidly across the DRC, making this the largest and deadliest outbreak the country has ever faced," CEPI chief executive Richard Hatchett said. [1]

Uganda's clearance and the DRC's escalating toll are not, in the end, two separate stories competing for space in the same wire update — they are the same outbreak's two possible outcomes, produced by the same porous, mobile border. Uganda's 15 imported cases prove the virus keeps crossing; its two deaths and 42-day closure prove that a well-resourced surveillance system can catch it quickly when it does. The DRC's Ituri Province epicenter has neither the conflict-free geography nor the surveillance density Uganda brought to its own five local infections. WHO's celebratory framing of Uganda's certification, standing next to the CDC's grim Congo milestone in the same day's news, is less a contradiction than an honest scorecard: the region's outbreak-response infrastructure works exactly as well as the state deploying it, and the Democratic Republic of Congo's is still being asked to do more, with less, against a strain nobody yet has a proven vaccine for.

-- KENJI NAKAMURA, Tokyo