Pneumonic Plague Deaths

What's confirmed and what isn't, with sources

Record updated Sources on file 17 Open questions 7

No health authority has confirmed a plague case: WHO says no cause of death has been officially confirmed and that on the unofficial information available the public health risk to the general population appears low, while 197 contacts were traced, 189 were hospitalized for observation, and officials say all have tested negative so far.

The four-sentence version

A 28-year-old laboratory assistant at the Irkutsk Anti-Plague Research Institute in Siberia, named in local reports as Darya Shipilova, was hospitalized in the nearby town of Shelekhov on Sep 29, 2026 with severe pneumonia and died in intensive care overnight on Oct 1-2.

Independent Russian outlets reported that she broke a test tube of live Yersinia pestis on Sep 25 while working with biological material, and that she died of pneumonic plague.

Rospotrebnadzor, Russia's public health watchdog, recorded the diagnosis as "pneumonia of unknown etiology", said extensive testing of her biomaterial found "no microorganisms associated with the patient's professional activities", and said no accident involving pathogenic microorganisms was recorded at the institute.

No health authority has confirmed a plague case: WHO says no cause of death has been officially confirmed and that on the unofficial information available the public health risk to the general population appears low, while 197 contacts were traced, 189 were hospitalized for observation, and officials say all have tested negative so far.

The count

Every figure carries the source that published it and the date it was published. Where a figure is zero it is written as a word, because a zero is a statement here and not a missing reading.

1

Deaths, cause unconfirmed

One laboratory worker died. Rospotrebnadzor recorded the cause as pneumonia of unknown etiology.

Rospotrebnadzor › via AP · Oct 5, 2026

189

Contacts hospitalized for observation

Out of 197 traced contacts. The Irkutsk governor says their laboratory results are negative and none show signs of illness.

Meduza · Gov. Igor Kobzev › via The Moscow Times · Oct 2, 2026

Confirmed plague cases None, 0

No health authority has confirmed Yersinia pestis in this death or in any traced contact.

WHO statement › via Newsweek · Oct 5, 2026

Countries with confirmed cases No country, 0

No country, Russia included, has confirmed a plague case tied to this event.

WHO statement › via Newsweek · Oct 5, 2026

On the record 10 sourced

  1. On the record

    A 28-year-old laboratory assistant at the Irkutsk Anti-Plague Research Institute was admitted to the Shelekhov district hospital on Sep 29, 2026 with severe pneumonia and died in intensive care.

    Meduza · Oct 2, 2026

  2. On the record

    Local outlets named her as Darya Shipilova. Rospotrebnadzor has not named her in its public statements.

    Lyudi Baikala › via RFE/RL · Oct 5, 2026

  3. On the record

    Rospotrebnadzor recorded the diagnosis as "pneumonia of unknown etiology" and said extensive testing found "no microorganisms associated with the patient's professional activities".

    AP › via PBS NewsHour · Oct 5, 2026

  4. On the record

    197 people were traced as contacts and 189 of them were hospitalized for observation and preventive antibiotics.

    Discover Magazine · Meduza · Oct 5, 2026

  5. On the record

    Testing of the contacts turned up two COVID-19 cases and two rhinovirus infections, with no other disease-causing organisms detected.

    Rospotrebnadzor › via Interfax, reported by Discover Magazine · Oct 4, 2026

  6. On the record

    Irkutsk governor Igor Kobzev said: "All identified contact persons have been placed under medical observation. As of today, the contacts show no signs of illness, and their laboratory test results are negative."

    The Moscow Times · Oct 2, 2026

  7. On the record

    Kobzev convened the regional anti-epidemic commission and Anna Popova, Russia's chief sanitary officer, travelled to Irkutsk on Oct 2.

    Meduza · Celine Gounder · Oct 2, 2026

  8. On the record

    WHO said it is aware of reports that a laboratory worker in Irkutsk "died of severe pneumonia", that "to date, no cause of death has been officially confirmed, and laboratory testing is reportedly underway", and that "based on unofficial information available, the public health risk to the general population appears to be low".

    WHO › via Newsweek · Oct 5, 2026

  9. On the record

    The US State Department said it is "monitoring the situation closely with the CDC and our other interagency partners" and encouraged Russian authorities to share accurate information quickly and openly. Secretary of State Marco Rubio said: "I don't think it's cause for alarm, but it is cause for focus."

    Al Jazeera · RFE/RL · Oct 5, 2026

  10. On the record

    Kremlin spokesman Dmitry Peskov told the public to follow official Rospotrebnadzor statements rather than "rumors or speculation".

    AP › via PBS NewsHour · Oct 5, 2026

In dispute 7 unresolved, 3 unanswered

  1. Disputed

    The cause of death. See open question 01 of 07.

  2. Disputed

    Whether there was a laboratory accident at all. See open question 02 of 07.

  3. Disputed

    The date she died. See open question 03 of 07.

  4. Disputed

    Her age. See open question 04 of 07.

  5. Disputed

    What happened between Sep 25 and Sep 29. See open question 05 of 07.

  6. Disputed

    How many medical facilities are under quarantine. See open question 06 of 07.

  7. Disputed

    Where the institute sits. See open question 07 of 07.

  8. Unconfirmed

    Everything Russia has not released: her vaccination status, her laboratory test results, which pathogen if any was identified, what antibiotics she was given and with what outcome, and her exact duties at the institute.

    Celine Gounder · Oct 6, 2026

  9. Unconfirmed

    Whether officials changed their account. Newsweek reports that Buryatia head Alexei Tsydenov's post was edited from saying the woman "died of plague in the Irkutsk region" to saying she "may have died of the plague". We have not seen an explanation for the edit.

    Newsweek · Meduza · Oct 2-5, 2026

  10. Unconfirmed

    No WHO Disease Outbreak News notice for plague in the Russian Federation turned up in our checks on Oct 5, 2026. WHO's global plague update of Sep 29, 2026 covers 2019 to 2025 and does not list Russia among the 10 countries that reported suspected human plague cases. Absence of a notice is not evidence either way about this case.

    Our own check of WHO Disease Outbreak News · WHO global trends update · Oct 5, 2026

Unresolved

Each card is a question nobody has answered, with the competing accounts set side by side and attributed. Nothing in this section is settled.

  1. Unresolved01 / 07

    The cause of death

    Nothing here resolves it.

  2. Unresolved02 / 07

    Whether there was a laboratory accident at all

    These two accounts cannot both be right.

  3. Unresolved03 / 07

    The date she died

    They appear to describe the same night, so this page carries it as Oct 1-2 rather than pick one.

  4. Unresolved04 / 07

    Her age

  5. Unresolved05 / 07

    What happened between Sep 25 and Sep 29

    The sequence in between is not established in any report we read.

  6. Unresolved06 / 07

    How many medical facilities are under quarantine

    The counts do not agree and we have seen no official list.

  7. Unresolved07 / 07

    Where the institute sits

    The institute's own site gives its address as 78 Trilisser Street, Irkutsk. The hospital where she died was in Shelekhov, which may be the source of the confusion.

How it unfolded

Oldest first. Entries marked unconfirmed rest on a single report or are contradicted by officials. The dashed rail and the hollow node mean the same thing as the word.

  1. On the record

    Russia's last recorded human plague case before this event: a 10-year-old in the Altai Republic.

    Meduza · Oct 2, 2026

  2. 10 years

    2026

    Unconfirmed

    The worker reportedly broke a test tube containing live Yersinia pestis while working with biological material at the institute. Rospotrebnadzor says no such accident was recorded. See open question 02 of 07.

    Lyudi Baikala › via RFE/RL · Oct 5, 2026

  3. Unconfirmed

    Her condition reportedly worsened and she was taken to hospital. Other reports date the admission two days later. See open question 05 of 07.

    Local media › via Euronews · Oct 4, 2026

  4. On the record

    She was admitted to the Shelekhov district hospital with severe pneumonia.

    Meduza · RFE/RL · Oct 2, 2026

  5. On the record

    WHO published its global plague trends update for 2019 to 2025. Russia is not among the 10 countries listed as reporting suspected human plague cases.

    WHO · Sep 29, 2026

  6. On the record

    Reports that the Shelekhov district hospital's inpatient department had closed appeared on social media.

    Meduza · Oct 2, 2026

  7. Disputed

    She died in the intensive care unit. Sources disagree on whether the death falls on Oct 1 or in the early hours of Oct 2. See open question 03 of 07.

    RFE/RL · Euronews · Newsweek · Oct 5, 2026

  8. On the record

    Shelekhov district mayor Maxim Modin confirmed the hospital was under quarantine. Governor Igor Kobzev convened the regional anti-epidemic commission and Anna Popova, Russia's chief sanitary officer, travelled to Irkutsk.

    Meduza · Oct 2, 2026

  9. On the record

    More than 60 institute staff were confined to the building.

    RFE/RL · Oct 5, 2026

  10. On the record

    Kobzev said all identified contacts were under medical observation, showed no signs of illness, and had negative laboratory results.

    The Moscow Times · Oct 2, 2026

  11. On the record

    Buryatia head Alexei Tsydenov posted that the woman had died of plague, then edited the post to say she may have died of plague. He said there are no plague outbreaks in Buryatia, including the areas bordering Mongolia.

    Newsweek · Meduza · Oct 5, 2026

  12. On the record

    The Irkutsk Aluminum Plant required staff to wear masks as a precaution.

    RFE/RL · AP › via PBS NewsHour · Oct 5, 2026

  13. On the record

    Rospotrebnadzor said its inspection found no accidents involving disease-causing microorganisms at the institute, and that contact testing turned up two COVID-19 cases and two rhinovirus infections and nothing else.

    Rospotrebnadzor › via Interfax, reported by Discover Magazine · Oct 5, 2026

  14. On the record

    WHO said no cause of death has been officially confirmed, that laboratory testing is reportedly underway, and that on unofficial information the public health risk to the general population appears to be low.

    WHO › via Newsweek · Oct 5, 2026

  15. On the record

    The US State Department said it is monitoring the situation with the CDC and urged Russia to share information openly. Secretary of State Marco Rubio said it is not cause for alarm but is cause for focus.

    Al Jazeera · RFE/RL · Oct 5, 2026

  16. On the record

    Kobzev said close contacts could be sent home the following week.

    Celine Gounder · Oct 6, 2026

Get told when this record changes

One email when a figure, a date or an open question changes. Not a newsletter, and the list is ours rather than a third party's.

Where

3 places named in the reports. Distances are computed from the coordinates in data.json. There is no map: three pins inside a box 240 km across tell a reader nothing that these lines do not.

  1. Irkutsk Measures in place

    52.2869 N, 104.3050 E Irkutsk Oblast, Russia

    Confirmed plague cases: 0

    Home of the Irkutsk Anti-Plague Research Institute of Siberia and the Far East, address 78 Trilisser Street. More than 60 staff were confined to the building from Oct 2. Several city medical facilities were reported under quarantine.

    RFE/RL · Meduza · Oct 5, 2026

    View Irkutsk on OpenStreetMap ↗ (opens in a new tab)

  2. Shelekhov 1 death reported

    52.2117 N, 104.1033 E 16 km south-west of Irkutsk · Irkutsk Oblast, Russia

    Confirmed plague cases: 0

    The worker was hospitalized at the Shelekhov district hospital on Sep 29 and died there in intensive care. The inpatient department was placed under quarantine, confirmed by district mayor Maxim Modin on Oct 2.

    Meduza · Euronews · Oct 2, 2026

    View Shelekhov on OpenStreetMap ↗ (opens in a new tab)

  3. Ulan-Ude No cases reported

    51.8336 N, 107.5840 E 230 km east of Irkutsk · Republic of Buryatia, Russia

    Confirmed plague cases: 0

    Buryatia's head Alexei Tsydenov posted that the woman had died of plague, then edited the post to say she may have died of plague. He said there are no plague outbreaks in the republic, including the areas bordering Mongolia.

    Newsweek · Meduza · Oct 2, 2026

    View Ulan-Ude on OpenStreetMap ↗ (opens in a new tab)

Named buildings and sites

  • Irkutsk Anti-Plague Research Institute of Siberia and the Far East

    Where the worker was employed. Founded 1934, the reference laboratory for especially dangerous infections in Siberia and the Far East. More than 60 staff confined to the building from Oct 2.

    RFE/RL · Oct 5, 2026

  • Shelekhov district hospital

    Where she was admitted on Sep 29 and where she died. Inpatient department quarantined, outpatient clinic reported to remain open.

    Meduza · Oct 2, 2026

  • Irkutsk municipal hospitals No. 1, No. 3 and No. 10

    Named in reports of quarantined facilities. No official list of quarantined facilities has been published, and the counts in different reports do not agree.

    Turkiye Today, citing Lyudi Baikala · Oct 4, 2026

  • Ivano-Matreninskaya Children's Hospital, Irkutsk

    Also named in reports of quarantined facilities.

    Turkiye Today, citing Lyudi Baikala · Oct 4, 2026

  • An Irkutsk maternity hospital

    Named in reports of quarantined facilities, not identified by name in those reports.

    Turkiye Today · Newsweek · Oct 5, 2026

  • Irkutsk Aluminum Plant

    Introduced a staff mask requirement on Oct 3 as a precaution, per its director Artyom Fominykh.

    RFE/RL · AP › via PBS NewsHour · Oct 5, 2026

What pneumonic plague is

The lines below are taken from the WHO plague fact sheet and the US CDC. They describe the disease in general. They are not a statement about this case, which no authority has confirmed as plague.

What is pneumonic plague?

WHO describes three main clinical forms of plague infection: bubonic, pneumonic and septicaemic. The pneumonic form affects the lungs and produces "severe respiratory symptoms such as shortness of breath and coughing, often with blood-tainted sputum".

WHO plague fact sheet

How fast does it move?

WHO says incubation "can be as short as 24 hours", that pneumonic plague is "invariably fatal unless treated early", and that it can be fatal within 18 to 24 hours of disease onset if left untreated. The CDC puts the incubation period following inhalation at as short as one day.

WHO plague fact sheet · CDC, Signs and Symptoms

Can it pass from person to person?

Yes. WHO: "Any person with pneumonic plague may transmit the disease via respiratory particles to other humans." The CDC says people with plague pneumonia can cough droplets containing the bacteria into the air and that inhaling those droplets can cause pneumonic plague in another person. The CDC also notes that person-to-person spread has not been documented in the United States since 1924.

WHO plague fact sheet · CDC, How It Spreads

Is it treatable?

WHO: "Recovery rates are high if detected and treated in time (within 24 hours of onset of symptoms)", and common antibiotics for gram-negative rods can effectively cure the disease if delivered early. The window is the whole point: treatment has to start fast.

WHO plague fact sheet

What should I do if I think I was exposed, or I have symptoms?

The CDC says to seek immediate medical attention if you have symptoms such as fever, headache, weakness and rapidly developing pneumonia with shortness of breath, chest pain and cough, and that prompt treatment with the correct medications is critical to prevent complications or death. Tell the clinician about the possible exposure so they can start the right antibiotic.

CDC, Signs and Symptoms

How common is plague worldwide?

WHO reported on Sep 29, 2026 that between 2019 and 2025, 10 countries reported suspected human plague cases to WHO, six of which reported confirmed cases, for a total of 3,847 suspected cases and 423 deaths, a case fatality rate of 11%. Most cases came from the Democratic Republic of the Congo and Madagascar, where plague remains endemic in some areas.

WHO global trends update, Sep 29, 2026

This page is a news tracker, not medical advice. If you are worried about symptoms or a possible exposure, contact a doctor or your local public health authority.

Sources, numbered

Every claim above traces back to one of these. Links open in a new tab so that checking a citation does not cost you your place on the page.

  1. [1]

    Meduza

    Shelekhov district hospital inpatient department quarantined; the worker named as Darya Shipilova, 28; admitted Sep 29; nearly 200 contacts with 189 hospitalized; officials named; Russia's last plague case in 2016.

    Oct 2, 2026

    meduza.io ↗ (opens in a new tab)
  2. [2]

    The Moscow Times

    At least 197 potential contacts placed under isolation, more than 100 in hospital wards; Governor Igor Kobzev's statement that contacts show no signs of illness and test negative; attribution to Lyudi Baikala, REN TV and Govorit_NeMoskva.

    Oct 2, 2026

    themoscowtimes.com ↗ (opens in a new tab)
  3. [3]

    Euronews

    Timeline of Sep 25 test tube break, Sep 27 worsening, Oct 2 death in Shelekhov district hospital ICU; Rospotrebnadzor's "pneumonia of unknown aetiology" and its statement that the regional situation is stable.

    Oct 4, 2026

    euronews.com ↗ (opens in a new tab)
  4. [4]

    Turkiye Today

    Named five quarantined medical facilities in the Irkutsk region; 197 contacts and 189 hospitalized; gave the worker's age as 27.

    Oct 4, 2026

    turkiyetoday.com ↗ (opens in a new tab)
  5. [5]

    RFE/RL

    Shipilova hospitalized Sep 29 and died early Oct 2; the Lyudi Baikala broken test tube account; Rospotrebnadzor's denial of any accident; more than 60 staff confined from Oct 2; Irkutsk Aluminum Plant mask rule Oct 3; Rubio's "cause for focus" line.

    Oct 5, 2026

    rferl.org ↗ (opens in a new tab)
  6. [6]

    AP, via PBS NewsHour

    Rospotrebnadzor's "pneumonia of unknown etiology" and "no microorganisms associated with the patient's professional activities"; two cold virus and two COVID-19 positives among contacts; Kobzev on "a particularly dangerous infection"; Peskov on rumors; the aluminum plant mask rule.

    Oct 5, 2026

    pbs.org ↗ (opens in a new tab)
  7. [7]

    ABC News (AP wire)

    Same Rospotrebnadzor statements; Kobzev's "under medical supervision" line; Trump's remarks on the disease; Rubio saying the US is watching the case closely.

    Oct 5, 2026

    abcnews.com ↗ (opens in a new tab)
  8. [8]

    CBS News

    Rospotrebnadzor saying "there had been no accident at the Irkutsk Anti-Plague Institute" and that no pathogens causing dangerous infections were found in nearly 200 contacts; credits Lyudi Baikala and Astra for documenting officials' statements and later deletions.

    Oct 5, 2026

    cbsnews.com ↗ (opens in a new tab)
  9. [9]

    Al Jazeera

    The US State Department monitoring with the CDC and urging Russia to share information quickly and openly; Rospotrebnadzor's diagnosis via TASS; the institute's full name.

    Oct 5, 2026

    aljazeera.com ↗ (opens in a new tab)
  10. [10]

    Newsweek

    WHO's statement that no cause of death has been officially confirmed and that risk to the general population appears low; death placed overnight Oct 1; 60 staff isolated; the Tsydenov post edit; four hospitals plus a maternity hospital quarantined; institute founded 1934.

    Oct 5, 2026

    newsweek.com ↗ (opens in a new tab)
  11. [11]

    TIME

    Overview of the quarantine and the Baikal Journal reporting; expert commentary from Dr. Simon Clarke of the University of Reading; Peskov's remarks via TASS.

    Oct 5, 2026

    time.com ↗ (opens in a new tab)
  12. [12]

    Discover Magazine

    197 people identified as potential contacts with 189 hospitalized for observation; Rospotrebnadzor via Interfax saying inspections found no accidents involving disease-causing microorganisms; the two COVID-19 and two rhinovirus results.

    Oct 5, 2026

    discovermagazine.com ↗ (opens in a new tab)
  13. [13]

    Dr. Celine Gounder

    An itemised list of what Russia has not confirmed: cause of death, laboratory results, which pathogen, vaccination status, antibiotics given, and the worker's duties. Also Anna Popova's Oct 2 arrival, six facilities under quarantine, and Kobzev saying close contacts could go home the following week.

    Oct 6, 2026

    celinegounder.com ↗ (opens in a new tab)
  14. [14]

    WHO, plague fact sheet

    The three clinical forms; incubation as short as 24 hours; pneumonic plague invariably fatal unless treated early and fatal within 18 to 24 hours of onset if untreated; person-to-person transmission via respiratory particles; high recovery rates if treated within 24 hours of onset.

    Reference page

    who.int ↗ (opens in a new tab)
  15. [15]

    WHO, global trends in cholera, meningitis and plague

    Between 2019 and 2025, 10 countries reported suspected human plague cases to WHO, six with confirmed cases; 3,847 suspected cases and 423 deaths, a case fatality rate of 11%; most from the Democratic Republic of the Congo and Madagascar. Russia is not listed.

    Sep 29, 2026

    who.int ↗ (opens in a new tab)
  16. [16]

    CDC, How Plague Spreads

    People and animals with plague pneumonia can cough droplets containing plague bacteria into the air, and inhaling those droplets can cause pneumonic plague in another person. Person-to-person spread has not been documented in the United States since 1924.

    Reference page

    cdc.gov ↗ (opens in a new tab)
  17. [17]

    CDC, Plague Signs and Symptoms

    Pneumonic plague symptoms: fever, headache, weakness, rapidly developing pneumonia with shortness of breath, chest pain, cough and sometimes bloody or watery mucous. Incubation following inhalation as short as one day. Seek immediate medical attention.

    Reference page

    cdc.gov ↗ (opens in a new tab)