EVIDENCE OVER TIME
Irkutsk incident timeline
One reported event, several stages of evidence. This timeline separates what happened, when a source reported it and when our map changed.
Published and reviewed October 15, 2026 · Latest incident assessment: WHO, October 10
The original worker's death is reported, but it is not a confirmed plague death. Current confirmed and suspected plague counts are not established. Read the current assessment.
Reported events and official assessments
September 29: hospitalization
WHO's October 10 account dates the worker's hospitalization for severe pneumonia to September 29. This is an event date reported later, not a September publication by this site. WHO account.
October 2: death and initial investigation
WHO dates the death to October 2 and says it learned of the event through media reporting that day. The original reports raised possible pneumonic plague. They did not establish a laboratory diagnosis. WHO event history.
October 6: ECDC describes suspected plague
ECDC said it was monitoring the reported fatal pneumonia and described plague as suspected. It reported no secondary cases in the limited information then available. This was an early assessment, not confirmation. ECDC statement.
October 10: WHO publishes its detailed assessment
WHO relayed Russian authorities' negative testing and completed contact follow-up. It had identified no evidence of ongoing transmission from that information, but the fatal illness remained undiagnosed. WHO said laboratory exposure could not be fully excluded and further investigation was needed. WHO Disease Outbreak News.
October 12: Hong Kong adds precautionary surveillance
Hong Kong's Centre for Health Protection described precautionary airport and clinical surveillance. It reported no recent unexplained-pneumonia cases among arrivals from Russia. These measures do not establish a new plague case or justify a Hong Kong pin. CHP statement.
Public map history and corrections
These are Plague Map's editorial decisions, not official classifications issued by WHO.
- October 5: launch. One approximate Shelekhov location, Unconfirmed, with no established case count.
- October 6: reclassified as Suspected. ECDC's incident statement supported displaying the historical report of one suspected case. The reported death referred to the same worker, not an additional person.
- October 7 and 9: follow-up reviews. Added attributed responses and unresolved questions. No unverified second case or death was added.
- October 12: reclassified as Unconfirmed. WHO's later report described an undiagnosed pneumonia event after reported negative testing. We cleared the current case count and kept the earlier suspected figure only as history. Current confirmed and suspected headline counts and case fatality are N/A; the original reported death remained explicitly unconfirmed as plague-related.
- October 13 and 15: status unchanged. Source checks found no newer official incident report changing the assessment. The map's source date remains October 10.
How to read historical reports
An old suspected-case figure is not today's tally. Contacts under observation are not cases. A later publication can describe an earlier event. Ending contact monitoring does not, by itself, identify the cause of death. A map review date does not establish that transmission is occurring.
To compare sources, check the event date, publication date, diagnostic evidence and whether a later assessment supersedes the claim. Our current brief puts the latest assessment first; this page preserves the chronology.
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