Will a confirmed human case of pneumonic plague be reported in the United States before December 1, 2026?

- [2026-07-11] Coconino County, Arizona confirmed a human death from pneumonic plague — the county's first pneumonic-plague fatality since 2007; this is a genuine confirmed U.S. domestic case, but it predates the contract's Oct 5, 2026 "Issuance" start and therefore cannot itself trigger Yes resolution. https://publichealthreview.substack.com/p/the-return-of-pneumonic-plague-in - [2026-04-15] A separate bubonic (non-pneumonic) plague case was confirmed in Apache County, Arizona, described at the time as "the only known human plague infection reported in the United States so far in 2026" (prior to the July Coconino fatality); illustrates the CDC's ordinary baseline of roughly seven U.S. plague cases per year, mostly bubonic. https://www.kdhe.ks.gov/DocumentCenter/View/57607/Weekly-Domestic-and-International-Infectious-Disease-Report-4-15-2026-PDF - [2026-10-02] A 28-year-old lab technician (Darya Shipilova) at the Irkutsk Anti-Plague Research Institute in Siberia, Russia, died of "pneumonia of unknown etiology"; nearly 200 contacts were placed under medical observation/quarantine. https://www.themoscowtimes.com/2026/10/02/nearly-200-people-under-observation-after-irkutsk-lab-worker-dies-from-plague-a93857 - [2026-10-04] The U.S. State Department said it was "aware of reports of a fatal case of suspected pneumonic plague in Irkutsk Oblast, Russia" and is "monitoring the situation closely with the CDC and our other interagency partners," but stressed many details were unconfirmed. https://www.mycentraloregon.com/2026/10/05/state-department-monitoring-reported-fatal-case-of-pneumonic-plague-in-russia/ - [2026-10-05] President Trump told reporters the U.S. is "willing to help Russia as much as we can" with the suspected outbreak; no reports of any American exposure, travel link, or U.S. patient. https://www.axios.com/2026/10/05/trump-us-russia-pneumonic-plague-risk-outbreak - [2026-10-05] CNN/ABC17 reported Russian authorities found a 28-year-old lab researcher died of pneumonia of an "unknown" origin, and the US State Department and CDC said they are monitoring the situation closely — no confirmation of plague by Russia and no indication of U.S. case. https://abc17news.com/cnn-health/2026/10/05/what-is-pneumonic-plague-and-how-dangerous-is-it/ - [2026-10-06] WHO spokesperson Christian Lindmeier stated "No cause of death has been officially confirmed to date and laboratory testing is reportedly underway" , and that according to Russian health authorities "no pathogens of dangerous infectious diseases were detected among any of the contacts." https://www.unognewsroom.org/story/en/3289/irkutsk-suspected-plague-death-who - [2026-10-06] A dedicated tracker (Plague Intel) summarized that as of Oct 6, Rospotrebnadzor maintains the cause of death is "pneumonia of undetermined etiology" and has not confirmed plague , with 189 hospitalized contacts testing negative so far. https://plagueintel.com/ - [2026-10-05] RFE/RL reported staff at the Irkutsk institute have been isolated since Oct 2, with a source noting "by Saturday (October 3), not a single positive test had been found" among those quarantined. https://www.rferl.org/a/russia-plague-warning-siberia-irkutsk-laboratory/33870385.html - [2026-10-05] Newsweek noted experts flagged the lack of released lab data, quoting a plague-news editor: "Four days after her death the official cause is still 'unknown origin', and no other cause has been named." https://www.newsweek.com/russia-plague-5-unanswered-questions-12529612 - [2026-10-05] CDC's own statement, as relayed by multiple outlets, says only that it is "monitoring the situation closely with the State Department and our other interagency partners... The safety and security of U.S. citizens is our highest priority" — no mention of any domestic case tied to Russia. https://www.yahoo.com/news/world/articles/cdc-monitoring-suspected-russia-pneumonic-183624382.html - [2026-05-30] The CDC's National Notifiable Diseases Surveillance System weekly "Plague" table (Week 21) is the official resolution-relevant tracker; it records case counts nationally on a rolling basis but requires a new filing after Oct 5, 2026 to independently confirm any new pneumonic case. https://stacks.cdc.gov/view/cdc/256932 BOTTOM LINE: As of October 6, 2026, there is no confirmed human pneumonic-plague case in the United States tied to the Russian Irkutsk incident or otherwise reported since the market's October 5 issuance; the Russian case itself remains officially unconfirmed as plague by Rospotrebnadzor and WHO, and U.S. agencies (CDC, State Department) describe only monitoring, not any domestic exposure or patient. The U.S. does have an ordinary background rate of a handful of plague cases per year (including one pneumonic fatality in Arizona in July 2026, before Issuance), so a sporadic, unrelated domestic case before Dec 1 remains possible but unconfirmed at present. NOT FOUND: No report of any U.S. resident, traveler, or lab contact being diagnosed, tested, or hospitalized for suspected/confirmed pneumonic plague since Oct 5, 2026; no CDC weekly surveillance table or press release dated after Oct 5, 2026 was available to check for a newly logged case; no confirmation from Russian authorities that the Irkutsk death was definitively Yersinia pestis as of Oct 6, 2026.

- [2015-01] CDC/EID historical surveillance found that among 913 U.S. plague cases 1900–2012 with documented clinical form, 744 (82%) were bubonic, 74 (8%) pneumonic, 87 (10%) septicemic, 6 (1%) pharyngeal, and 2 (<1%) gastrointestinal , implying roughly 0.65 pneumonic cases per year averaged over that 113-year span. https://wwwnc.cdc.gov/eid/article/21/1/14-0564_article - [2024-05] CDC's official statistics page states in recent decades, an average of seven human plague cases have been reported each year (range: 0–17 cases per year) , with over 80% of United States plague cases have been the bubonic form , leaving pneumonic plague as a small minority of an already-rare disease. https://www.cdc.gov/plague/maps-statistics/index.html - [2009] A clinical reference summarizing CDC unpublished data found that in the United States from 1960 to 2008, 55 cases of secondary plague pneumonia and 11 cases of primary plague pneumonia were reported to the CDC, with no known secondary transmission to contacts — roughly 0.2 primary pneumonic cases/year historically. https://www.sciencedirect.com/topics/pharmacology-toxicology-and-pharmaceutical-science/pneumonic-plague - [1984] An older CDC MMWR noted primary pneumonic plague in the United States has been described as rare, with only three cases between 1926 and 1977--all in laboratory workers; however, since 1975, four persons have developed primary pneumonic plague, presumably from exposure to household pets , and that no transmission to contacts of patients with pneumonic plague has been documented in the United States since 1925 . https://cdc.gov/MMWr/preview/mmwrhtml/00000124.htm - [2026-10-01] CDC MMWR confirmed that in July 2025, Arizona reported its first pneumonic plague death since 2007, in a man with occupational exposure to ill cats , and that only eight human plague cases were reported in Arizona during 2000–2024 — the most recent confirmed U.S. pneumonic plague case, about 15 months before the question window opened. https://www.cdc.gov/mmwr/volumes/75/wr/mm7538a2.htm - [2026-04-15] A Kansas health department infectious-disease report stated that the Apache County case is the only known human plague infection reported in the United States so far in 2026 , and that case was officially described as bubonic, not pneumonic. https://www.kdhe.ks.gov/DocumentCenter/View/57607/Weekly-Domestic-and-International-Infectious-Disease-Report-4-15-2026-PDF - [2026-06-11] New Mexico's health department reported its first 2026 human plague case (fatal), with no indication it was pneumonic rather than bubonic/septicemic: A Santa Fe County woman has died from plague—the first human case in New Mexico in 2026, the New Mexico Department of Health reports . https://www.nmhealth.org/news/awareness/2026/6/?view=2344 - [2026-10-05] Base-rate context has shifted due to an unconfirmed foreign event: on Sept. 25, 28-year-old Daria Shipilova, who worked at an anti-plague research institute in Russia's Irkutsk region, broke a test tube containing the pneumonic plague pathogen, local reports said... Shipilova was admitted to a hospital on Sept. 29 with symptoms of severe pneumonia and died overnight between Oct. 1 and Oct. 2 , but Russia's public health agency said Shipilova had "pneumonia of unknown etiology" and that further testing found no microorganisms linked to her work — the diagnosis remains unconfirmed by Russian authorities, and no travel-linked or imported U.S. case has been reported. - [2026-10-05] U.S. officials have only announced monitoring, not any confirmed domestic case: a State Department official told Fox News that the U.S. is aware of reports of a death in Irkutsk Oblast... and is watching the situation closely with the Centers for Disease Control and Prevention and other federal agencies , with no U.S. travel restrictions or case identification announced. https://www.wfmd.com/2026/10/04/us-monitoring-suspected-fatal-pneumonic-plague-case-in-russia-state-department-official-says/ - [2026-10-05] Public health experts downplay transmission risk: Reports of a local outbreak of the pneumonic plague in a laboratory in Russia's eastern Siberian region of Irkutsk has raised alarm, but Northeastern University experts and U.S. government officials say there is little evidence so far of wider transmission . https://news.northeastern.edu/2026/10/05/outbreak-plague-russia-analysis/ NOT FOUND: No Kalshi, Polymarket or other prediction-market historical base rates specifically for "pneumonic plague in the US" questions; no formal epidemiological forecast/model estimating probability of a U.S. pneumonic plague case by a specific date; no confirmation that the Russian lab worker's death was definitively plague (it remains unconfirmed by Russian health authorities as of Oct 6, 2026). BOTTOM LINE: Historically, confirmed primary pneumonic plague cases in the U.S. are extremely rare (roughly 0–1 per year, often zero in most years, with human-to-human transmission not documented since 1925), and the most recent one occurred in July 2025 (Arizona); absent the ongoing domestic endemic pattern, the base rate alone would imply a low probability of a new confirmed U.S. pneumonic case within any given ~8-week window, though the unresolved Russian incident introduces unusual (but so far unconfirmed and not U.S.-linked) upside risk.

YES means: A confirmed human case of pneumonic plague is officially reported by a Source Agency as occurring in the United States, with first initial confirmation between Oct 5, 2026 and the start of Dec 1, 2026 (imported/travel-linked cases count). - [2026-10-01] The CDC's own retrospective case report on the July 2025 Arizona pneumonic-plague death states it followed work-related contact with two sick indoor cats shortly before he became ill, both with respiratory symptoms, exposed five and four days before illness began , confirming that ordinary zoonotic/pet-exposure pneumonic transmission (not requiring any Russia link) is an active, documented U.S. pathway, with a case as recent as 15 months before the window opened. - [2026-10-05] New Mexico and Arizona officials describe plague as a recurring seasonal hazard: the CDC reports an average of about seven human cases annually in recent decades, with most infections acquired in rural areas of northern New Mexico, northern Arizona, southern Colorado, California, southern Oregon and far western Nevada, and Arizona sits within one of the main US plague foci, so sporadic human infections continue to occur, even in years with very low national activity — the Oct–Dec window still falls partly within or just after the historical plague season. - [2026-10-05] Secretary of State Marco Rubio publicly flagged plausible international spread risk, warning that despite there being "very limited travel between the U.S. and Russia," if "something like that gets out, it could quickly spread" — an unusually high-level acknowledgment that a travel-linked imported case is on officials' minds, which would also qualify under the rules since imported cases count. - [2026-10-05] A senior U.S. health official's framing shows the only firewall against a resolving case is air travel: "We don't have a lot of intel," said one U.S. health official. "It's in Siberia. Unless someone gets on a plane and gets to the U.S., it is low risk. We should be alert but not panicked." This implicitly concedes that any undetected incubating contact boarding a flight to the U.S. is the single scenario that would trigger a Yes. - [2026-10-06] Incubation-period data compounds this exposure risk: pneumonic plague's incubation is very short, with the incubation period for this type of plague up to six or seven days , meaning any contact who traveled before full containment measures could already be past undetected incubation by now, or a late traveler could still develop symptoms before the Dec 1 deadline. - [2026-10-05] Historical CDC Yellow Book data shows imported cases are not unprecedented, even though rare: no plague cases have been reported among travelers returning to the United States in >40 years — this sets a very low but non-zero historical base, and a large-scale foreign lab incident (Irkutsk) is an atypical forcing event not reflected in that quiet 40-year baseline. - [2026-10-05] New Mexico's own domestic surveillance shows plague is not confined to a single annual event: New Mexico recorded three human plague cases in 2025, and one in 2024, which was fatal — multiple cases per year in endemic states is common, and if even one of the roughly seven annual U.S. cases that typically occur is pneumonic (as in 2025), the base rate alone supports a non-trivial chance of a new domestic pneumonic case by Dec 1 independent of Russia. - [2026-10-05] Historical precedent for sporadic domestic pneumonic clusters outside lab/travel contexts exists: in 2024, worldwide, cases of plague were reported in four countries: the Democratic Republic of the Congo, the Republic of Madagascar, the United States of America (Colorado, New Mexico, Oregon), and the People's Republic of China, a total of 443 cases of plague were registered , confirming the U.S. remains one of the handful of countries with recurring annual plague activity, raising the odds that at least one of this year's cases could present as pneumonic. - [2026-10-05] Despite reassurances, officials have not ruled out risk escalation: Rubio added "I don't think it's cause for alarm, but it is cause for focus an[d attention]" , and the White House convened an interagency meeting, indicating the U.S. government itself regards the probability of spread as material enough to warrant elevated monitoring rather than dismissal. BOTTOM LINE: The strongest path to YES is not the Russian outbreak (still unconfirmed as plague, with no evidence of U.S. exposure), but the long-running, independent domestic background rate of ~7 U.S. plague cases per year in endemic Southwestern states, which produced a confirmed pneumonic fatality as recently as July 2025; combined with Rubio's explicit acknowledgment that a traveler could import the disease and trigger a qualifying imported case, there remains a plausible, evidence-grounded (if low-probability) route to a Yes resolution before December 1, 2026. NOT FOUND: No report of any suspected or confirmed U.S. pneumonic plague patient (domestic or travel-linked) since the Oct 5 Issuance date; no CDC weekly NNDSS update after Oct 5, 2026 was available to check for a newly logged case; no evidence any U.S. traveler departed Irkutsk or had contact with Shipilova.

YES means: a confirmed human case of pneumonic plague is officially reported by a Source Agency in the United States, first confirmed between Oct 5, 2026 and Dec 1, 2026 (imported cases count; domestic sporadic cases count; the unconfirmed Russian incident need not be the source). - [2026-10-06] The only acute plague story in the news cycle — the Irkutsk, Russia lab-worker death — remains entirely unconfirmed as plague by Russian authorities themselves: Rospotrebnadzor's own account is that testing found no pathogen linked to her work, and that "no microorganisms related to the girl's professional activities were found in her biological samples," per the Irkutsk governor. https://time.com/article/2026/10/05/russia-plague-fears-siberia-quarantine-lab-worker-died/ - [2026-10-06] Among the nearly 200 identified contacts in Russia, testing has turned up zero plague cases — "according to the test results, no pathogens of dangerous infectious diseases were detected among any of the contacts," per WHO's Geneva briefing — undercutting any narrative of an active, spreading pneumonic-plague event that could seed a U.S. case. https://time.com/article/2026/10/05/russia-plague-fears-siberia-quarantine-lab-worker-died/ - [2026-10-05] By October 5, Rospotrebnadzor had even "called the situation 'calm' and said medical observation had ended for 60% of contacts," with only two COVID-19 and two rhinovirus infections turning up among the rest — i.e., the one potential external vector for an imported U.S. case is actively being stood down. https://plagueintel.com/ - [2026-10-05] There is no direct transmission bridge: "there are currently no direct commercial flights between the United States and Russia, and Washington has not announced additional travel restrictions over the suspected case," meaning no imported-case pathway has been activated even precautionarily. https://www.novinite.com/articles/240876/Suspected+Plague+Death+Sparks+Quarantine+Across+Russia's+Irkutsk+Region - [2026-10-05] Secretary of State Rubio's own framing stresses the link is currently hypothetical, not active: "There's very limited travel between the U.S and Russia, obviously, but like anything else, something like that gets out and it could quickly spread" — a conditional statement about a scenario that hasn't occurred. https://time.com/article/2026/10/05/russia-plague-fears-siberia-quarantine-lab-worker-died/ - [2026-10-05] All official U.S. agency statements (State Department, CDC, HHS) describe only monitoring posture — "the safety and security of U.S. citizens is our highest priority" — with zero mention of any U.S. patient, traveler under observation, or domestic quarantine action. https://www.mycentraloregon.com/2026/10/05/state-department-monitoring-reported-fatal-case-of-pneumonic-plague-in-russia/ - [2022-06-16] CDC's own historical tally in the Wyoming MMWR report is the most precise base-rate figure available: "Nationwide, 18 cases of pneumonic plague were reported during 1942–2018" — a 77-year span, implying roughly 0.23 pneumonic cases per year nationally, an extremely low background rate for an ~8-week window. https://www.cdc.gov/mmwr/volumes/71/wr/mm7124a5.htm - [2026-10-05] Public-health experts contacted by outlets are actively downplaying any wider transmission risk from the Russian incident, with Northeastern University experts and U.S. officials saying "there is little evidence so far of wider transmission" — reinforcing that the acute pathway for an imported case is currently seen as weak. https://news.northeastern.edu/2026/10/05/outbreak-plague-russia-analysis/ - [2026-10-05] Former Rospotrebnadzor head Gennady Onishchenko told Russian media the Irkutsk infection was "likely not plague," and separately noted that cold weather by early October makes natural-focus rodent/flea transmission less likely — a seasonal factor that also depresses the sporadic-domestic-case base rate as the U.S. moves into winter before the Dec 1 deadline. https://eualive.net/what-the-irkutsk-plague-lab-case-does-and-does-not-show/ - [2026-10-05] Even sympathetic coverage flags the data vacuum: a plague-news editor noted "four days after her death the official cause is still 'unknown origin,' and no other cause has been named" — four days of testing produced no confirmation, suggesting further delay or an eventual non-plague finding is plausible, not a rapid confirmation that could cascade to a U.S. case. https://www.newsweek.com/russia-plague-5-unanswered-questions-12529612 BOTTOM LINE: Every concrete fact as of Oct 6, 2026 points toward containment and non-confirmation — Russia's own watchdog denies the lab accident and plague diagnosis, contact testing is negative, there is no commercial-flight bridge, and U.S. agencies report monitoring only, not any domestic case; combined with a historical pneumonic-plague base rate near 0.2–0.65 cases/year nationally (nearly all bubonic/septicemic domestically), the structural and statistical case for NO through Dec 1 is strong. NOT FOUND: No evidence of any U.S. resident, traveler, or Irkutsk-linked contact being tested, isolated, or hospitalized for suspected pneumonic plague on U.S. soil since Oct 5, 2026; no CDC travel advisory, quarantine-station alert, or NNDSS filing dated after Oct 5, 2026 confirming a new domestic pneumonic case; no independent (non-Russian-government) laboratory confirmation that the Irkutsk death was Yersinia pestis.