BUNIA, Congo — World Health Organization Director-General Tedros Adhanom Ghebreyesus opened a new Ebola treatment center on Sunday in this eastern Congolese city at the heart of an outbreak that has produced more than 900 suspected cases in two weeks, announcing that five patients infected with a rare strain of the virus have recovered without an approved vaccine or treatment.

The recoveries — four discharges Sunday and one Friday — offer the first documented evidence that the Bundibugyo strain, which the WHO says kills up to 50 percent of those infected, can be survived with supportive care alone. They land against grim arithmetic: the WHO has logged 906 suspected cases and 223 suspected deaths in Congo, with 134 confirmed cases and 18 confirmed deaths across Congo and neighboring Uganda, which has reported nine cases and one death.

What is new

Tedros's visit, which began Friday with a meeting alongside Congolese Prime Minister Judith Suminwa Tuluka, follows the May 27 decision by Uganda to seal its border with Congo against WHO advice and the Trump administration's plan to route exposed Americans to a quarantine facility under construction in Kenya rather than fly them home. The director-general toured Bunia's Rwampara and General hospitals, where Associated Press reporters observed additional staff, protective gear and medical supplies, with patients arriving around the clock.

Medical aid donated by the European Union reached Ituri province Thursday, and the United States announced $80 million in additional aid the same day, bringing its total commitment to more than $112 million.

A response behind the curve

Doctors Without Borders, known by its French acronym MSF, warned Saturday that the rescue effort has not kept pace with one of the fastest-spreading outbreaks on record. "Never before has an Ebola outbreak recorded so many cases so soon after its declaration," Alan Gonzalez, MSF's deputy director of operations, said in a statement. Gonzalez called for an immediate expansion of testing, faster deployment of aid workers and sustained access for medical supplies.

The charity said the Bundibugyo strain is particularly difficult to diagnose because of limited testing capacity, complicating any effort to map the true spread. The illness has also been reported in North Kivu and South Kivu provinces, where the Rwanda-backed M23 rebel group controls key cities including Goma and Bukavu. The rebels have reported two cases.

Attacks by the Allied Democratic Forces, a rebel group allied with the Islamic State, and a coalition of ethnic militias have hindered the medical response in Ituri. Residents angry over the stringent protocols required for handling victims' bodies — protocols that clash with local burial rites — have launched at least three attacks on health centers.

A pitch to come forward

Tedros used Sunday's center opening to press residents to seek care rather than hide symptoms, the lever the WHO has left in the absence of a vaccine. "If you come to health facilities when you have symptoms, you can get the support and recover, so the key is to come forward as early as possible and to get the necessary support," he said. Pierre Akilimali, incident manager at Congo's National Institute of Public Health, told the inauguration that symptomatic treatment is producing recoveries: "The final message we would like to share with the Ituri community is that there is hope."

Tedros also took aim at the border closures by Uganda and Rwanda and at last week's Trump administration ban on non-U.S. passport holders who recently visited Congo, Uganda or South Sudan. Such measures are "not effective at all" at containing the outbreak, he said, arguing they punish the transparent reporting Kinshasa has so far provided.

The counterview

No government that has shut its border or restricted travel was reached for comment in the wire reports drawn on for this account, and Uganda has stood by its frontier closure. The outbreak is Congo's 17th, and past episodes have been brought to heel only after months of work — a record that cuts both ways on Tedros's prediction that the country "can once again bring this outbreak under control."

The WHO has scheduled further shipments of European Union supplies in the coming days. The next official case count is expected this week.