At least one new laboratory-confirmed filovirus spillover (Ebola species, Marburg, or Sudan virus ≥1 human case) will be reported by WHO DON or Africa CDC in sub-Saharan Africa between 2026-04-20 and 2026-10-20. Base rate: 2024-2025 saw Rwanda Marburg (Oct 2024), Uganda SVD (Jan-Apr 2025), DRC Ebola (Sep-Dec 2025), Ethiopia Marburg (Nov 2025-Jan 2026) — 4 distinct filovirus spillovers in ~14 months.</magnitude> <parameter name="key_assumption">Great Lakes/East Africa/Horn-of-Africa filovirus reservoir ecology unchanged; WHO IHR reporting functioning; Africa CDC active surveillance in Centra...

System-generated assessment. This assessment remains under review until the stated horizon or until sufficient evidence allows evaluation.

Substantial confidence

Confidence in this assessment

70%

Multiple lines of evidence are aligned, though the assessment remains provisional. Based on 10 linked evidence items and assessed against 180D.

Assessed through 180D10 linked evidence itemsTracking since Apr 20, 2026

How this assessment will be evaluated

The criteria the system uses to determine whether this assessment is borne out by the stated horizon.

Automated

Method

Evidence Match

The condition the system checks for when evaluating this assessment.

Minimum source quality

T1Primary Institutional

Evidence must meet or exceed this credibility tier to count toward evaluation.

Required terms

laboratory-confirmedhorn-of-africasurveillancesub-saharan

Evidence quality mix

Tracking since Apr 20, 2026.

T13

T27

Integrity referencesCryptographic hashes for verification

Registration

Integrity anchor

Brier 0.202

19 resolved novel pathogen detection predictions.

Scope synthesis

The current analyst narrative for this scope.

Open synthesis →

Uganda Sudan Virus Disease outbreak declared over (Final Brief 16); Nigeria Lassa trajectory unchanged; Marburg male reproductive persistence study advances surveillance design.

Uganda Sudan VHF Final Brief confirms recent filovirus spillover in sub-Saharan Africa within hypothesis window

Evidence linked to this assessment

10 linked items.

Marburg virus disease - Rwanda. As of 19 December 2024, 66 confirmed cases,15 deaths with a case

Currently interpreted as supporting evidence for 5 tracked assessments.

0 cases · 15 deaths · 0 samples

T1https://www.who.int/emergencies/disease-outbreak-news/item/2024-DON548supports

Apr 17, 2026

Marburg virus disease - Rwanda. The last confirmed case was reported on 30 October 2024.

Currently interpreted as supporting evidence for 4 tracked assessments.

T1https://www.who.int/emergencies/disease-outbreak-news/item/2024-DON548