Ebola Tracker

Case Definitions

In Ebola surveillance, case categories have specific meanings:

• Confirmed: laboratory-confirmed Ebola virus infection via PCR or antigen test
• Suspected: meets clinical criteria (fever, bleeding, known contact exposure) but lab results are pending or unavailable
• Probable: clinical presentation consistent with Ebola where lab confirmation was not possible, typically due to death before testing

Suspected cases far outnumber confirmed cases in active outbreaks — the current outbreak has roughly a 9:1 ratio. This is normal. Suspected cases should not be read as confirmed infections.

Source Hierarchy and Conflicts

Ebola Tracker aggregates data from WHO Director-General media briefings (the most frequently updated source during active PHEICs), WHO Disease Outbreak News situation reports, WHO AFRO weekly situation reports, and CDC Current Situation summaries. These sources publish on different schedules and routinely show different figures for the same outbreak at the same time.

Differences between sources reflect:

• Reporting lag (CDC may update before or after WHO)
• Case definition variations between agencies
• Retroactive reclassification as lab results arrive
• Field investigation revisions

When sources conflict, Ebola Tracker displays the most recently published report per region. The originating source and report date are shown for every data point. For authoritative current figures, always consult the linked source directly.

Severity Scoring

Severity is calculated per region using:

Score = confirmed + (suspected × 0.5) + (deaths × 2)

HIGH   = score ≥ 200
MEDIUM = score ≥ 50
LOW    = score < 50

Deaths are weighted most heavily because mortality signal is the strongest indicator of outbreak severity when laboratory confirmation is limited. Scores are recalculated automatically when new data is ingested.

Data Freshness

Data is fetched automatically every 24 hours. The timestamp on the dashboard reflects when data was last successfully ingested — not when the underlying field event occurred.

Typical lag from field event to dashboard:

• WHO Director-General briefings: published every 2–3 days during active PHEIC — currently the most current source
• WHO Disease Outbreak News: published irregularly, typically 2–7 days after field reporting
• CDC Current Situation: updated periodically — may lag significantly during fast-moving outbreaks
• WHO AFRO: weekly cadence

This dashboard reflects what official agencies have publicly reported, not real-time field conditions. It is not a substitute for direct consultation of official sources during a rapidly evolving outbreak.

What This Site Is Not

Ebola Tracker does not conduct original surveillance, field investigation, or laboratory analysis. It does not receive embargoed or pre-publication data from any agency. All data is sourced from publicly available official reports.