Three clocks now define the surveillance failure [E1][E2][E3]. At a 10 August briefing in Bunia, WHO’s Africa director said sequencing indicated that the outbreak had started in February [E1]. The strongest public genomic analysis is narrower: 139 genomes produced central estimates of 8 March and 15 March, with intervals reaching 1 February and 9 February [E2]. Official recognition came on 15 May, ten days after WHO was alerted to an unknown high-mortality illness on 5 May [E3].
The diagnostic chain shows where the tripwire lost time [E1][E3]. Early illnesses were attributed to malaria and typhoid [E1]. In Rwampara, 20 initial samples tested negative on standard Ebola Xpert before specimens went to the national laboratory for further analysis [E3]. On 15 May, broader PCR testing identified Orthoebolavirus in eight samples, and sequencing established Bundibugyo virus [E3].
Clinicians had to cross two gates before escalation: clinical suspicion and assay selection [E1][E3]. A familiar fever diagnosis could keep an illness inside ordinary care pathways, while the initial Rwampara test returned negative [E1][E3]. Broader PCR and sequencing later crossed the second gate [E3]. Unusual mortality and clustered health-worker deaths had triggered the 5 May alert before the disease had a confirmed name [E3].
Genomics does not supply a patient-zero date [E2][E6]. The 139-genome analysis estimates the sampled viruses’ most recent common ancestor in mid-March, with uncertainty extending to early February [E2]. An earlier analysis warns that the reconstructed ancestor belongs to the sampled sequences and may differ from the outbreak’s true ancestor because sampling is uneven in space and time [E6]. February remains plausible; the evidence does not prove that a known clinical case occurred on 1 or 9 February [E2][E6].
By the time the system named the outbreak, the event was already large [E3]. WHO recorded 246 suspected cases and 80 deaths as of 15 May across Rwampara, Mongbwalu and Bunia [E3]. A 6 August WHO–Africa CDC release, using data through 4 August, reported 3,973 confirmed cases and 1,801 deaths [E4]. Congo’s national update through 7 August raised the count to 4,209 confirmed cases and 1,916 deaths across 53 of 140 health zones in five provinces [E5].
Responders have since moved the operational threshold closer to communities [E4]. WHO and Africa CDC called for testing, referral, isolation and treatment services nearer affected populations and set a contact-follow-up target of at least 95% [E4]. Their 4 August snapshot put follow-up at 75%, leaving a 20-point gap [E4]. Delayed detection, referral distance and incomplete contact coverage all buy an outbreak time before confirmation [E1][E3][E4].
The remaining uncertainty is how much transmission occurred before May [E2][E6]. Positive pre-May specimens or epidemiologically linked fatal clusters would strengthen the case for sustained earlier spread [E2][E6]. A denser genomic sample that pulled the ancestral interval toward late March or April would weaken the February formulation [E2]. For now, the genetic clock centers on March with a February tail, while official recognition arrived on 15 May [E1][E2][E3].