Known pathogen, unprepared system: Bundibugyo virus and the diagnostic preparedness gap

The 2026 Bundibugyo virus (BDBV) outbreak in the Democratic Republic of the Congo exposed a fundamental weakness in global diagnostic preparedness. Although BDBV had been recognized for nearly two decades and diagnostic tools existed, gaps across the diagnostic ecosystem delayed outbreak recognition and response. Scientific capability existed, but a resilient diagnostic ecosystem capable of translating existing technologies into timely public health action was lacking. The response to the BDBV outbreak should be understood not as an isolated diagnostic failure, but as a case study demonstrating why preparedness strategies built around individual pathogens are insufficient for future epidemic and pandemic threats. Diagnostic preparedness must shift toward adaptable syndromic and viral-family platforms, regional sequencing capacity, integrated surveillance systems, pre-positioned regulatory and validation pathways, resilient manufacturing, sustainable inter-epidemic financing, and clear global accountability. The outbreak raises broader questions. If the global community struggles to deploy diagnostics for a known pathogen, it is unlikely to respond effectively to a novel or highly divergent one. Building a fit-for-purpose diagnostic preparedness ecosystem is essential for achieving the 100 Days Mission and future pandemic preparedness.