Why the Ebola Outbreak Has Been Nearly Impossible to Stop

What It Covers

NYT correspondent Declan Walsh reports from Bunia, Democratic Republic of Congo, on an Ebola outbreak that went undetected for two to three months, has produced roughly 250 confirmed deaths and 1,100 suspected cases, and is already the third-largest outbreak on record, with conditions suggesting it could surpass all previous outbreaks.

Key Questions Answered

• •Strain-specific vaccine gap: The current outbreak involves the Bundibudyo strain, only the third such outbreak since it was first identified in Uganda in 2007. No vaccine or approved treatment exists for this strain, unlike the more common Zaire strain. Response teams must operate without the pharmaceutical tools that helped contain previous outbreaks, making early detection and isolation the only available containment strategy.
• •Delayed detection multiplies spread: The Bundibudyo strain initially produces symptoms — fever, headache — that mirror malaria and typhoid, both endemic in the region. Patients in Mangoalu sought traditional healers or small clinics first, only reaching hospitals in late-stage disease. Combined with a regional lab that tested only for Zaire Ebola, the outbreak circulated undetected for up to three months before identification, allowing hundreds of cases to accumulate before any response began.
• •USAID withdrawal degraded early-warning infrastructure: Aid workers on the ground state that the dismantling of USAID funding eliminated a network of local Congolese community organizations — not exclusively health-focused — that historically provided rapid-activation capacity during crises. That grassroots network, which could have flagged the mysterious wave of deaths in April, was absent when the outbreak began spreading through Mangoalu's mobile gold-mining population.
• •Traditional burial practices create super-spreader events: Congolese burial customs involve large numbers of mourners physically touching the deceased. Because Ebola-infected bodies remain highly contagious after death, each traditional funeral can generate dozens of new infections. Safe burial teams from the Red Cross — who disinfect, bag, and conduct dignified but contact-limited burials — face violent resistance from communities, making this cultural intervention one of the most operationally difficult elements of containment.
• •Contact tracing has not meaningfully begun: Cutting transmission chains requires mapping every contact of every confirmed case, but the scarcity of Bundibudyo-specific testing kits means results take four to six days — often after patients have already died. Without completed contact tracing, health officials cannot identify who needs isolation or monitoring, leaving the full geographic spread of the virus unknown and containment efforts structurally incomplete.