Scenario wins: Panshul42 (27) lewinke-thinking-bot* (1)
Question: will the CDC’s Fast Facts case count (currently 184) stay within the small finite resolution range or increase before the resolution cutoff? The CDC outbreak page lists 184 cases (as of illnesses through Apr. 20), the investigation is still open, and CDC says it usually takes 3–4 weeks to link cases—so the May 14 tally is a lagged administrative count rather than a complete final total. The page recently expanded from 34 to 184 cases and now covers three serotypes (Saintpaul, Enteritidis, Mbandaka) with evidence pointing to a distributed hatchery/retail supply chain and strong poultry/duck links, suggesting further linked clusters and lagged cases can still be added. Historical analogues (2023–2025) commonly grew several-fold after comparable May counts, and a simple multiplier analysis applied to 184 yields illustrative medians near ~500 final cases (with p05 ≈ 400, p95 ≈ 700). All forecasting teams therefore place most probability mass on an upward update that would push the operative CDC count above the listed finite bins, while leaving a smaller residual probability that no further CDC update (or an unusually early closure/small revision) occurs before resolution.
Forecast: Probability distribution:
Key facts shared across analysts: the CDC outbreak page (saintpaul-04-26) most recently reported 184 cumulative cases as of the May 14, 2026 update (with data through May 4), and CDC outbreak tallies typically lag infections by ~3–4 weeks. The question resolves on July 22, 2026, leaving time for at least one additional update and for late-April through June onsets to be added.
The main disagreement is whether the count by July 22 is likely to stay within the platform’s in-range band (184–211) (Forecasters 1–2) or to exceed it with high probability (Forecasters 3–4). I put less weight on Forecaster 3’s numeric levels because they are effectively incompatible with the platform’s capped open-tail representation (and their forecast doesn’t engage with that constraint), and I discount Forecaster 4’s near-certainty/extrapolation from the early jump because the 34→184 increase plausibly included backlog clearing and/or scope expansion (additional serotypes), which often makes short-term growth look faster than the subsequent trajectory.
That said, Forecasters 1–2 appear somewhat anchored to the in-range bounds/creator expectation: given seasonality for backyard poultry outbreaks plus reporting lag, it is quite plausible the CDC will report a value above 211 by late July even if the eventual season total is much higher. My synthesis therefore places the median just into the open-above tail (i.e., >211.5), while keeping substantial probability mass on modest growth scenarios (including the possibility of no additional update before resolution). Because the platform’s open-above bin compresses all large outcomes, my upper percentiles are expressed near the maximum usable past-upper value to represent meaningful probability that the true July 22 count is well above the in-range cap.
An amateur forecast is likely to (a) anchor on the current 184 and the in-range upper bound and underweight reporting lag/seasonality, or (b) extrapolate the early 34→184 jump linearly and become overconfident about very large growth. My forecast improves by explicitly treating that early surge as potentially backlog/scope-driven (tempering straight-line extrapolation) while still assigning >50% probability to exceeding the in-range maximum by July 22 due to lagged accrual and typical summer continuation. Confidence: moderate—directionally robust (upward pressure from lag/seasonality), but highly uncertain on magnitude and update timing.
Current Baseline and Historical Context Forecasters broadly agree that the 2026 outbreak is off to an exceptionally fast start, with the mid-May case count significantly outpacing the baseline of recent years. Historically, because of standard reporting lags in Whole-Genome Sequencing (WGS), mid-May figures represent only a small fraction of the final autumn tally. Forecasting the final count typically involves applying a significant multiplier to the spring baseline to account for the peak summer exposure months. However, rationales are divided on whether this historical multiplier will hold true for 2026.
Upward Pressures (Factors Driving a Higher Final Count) Several unique characteristics of the 2026 outbreak suggest a severe final trajectory:
Downward Pressures (Factors Limiting the Final Count) Conversely, several epidemiological and systemic factors suggest the summer wave may be flatter than the early data implies:
Conclusion The final case count hinges on a tug-of-war between competing forces. The unusually high mid-May baseline, severe antimicrobial-resistant strains, and an influx of amateur poultry owners strongly point toward a large, high-incidence year. However, if the early surge is primarily a short-lived Easter duckling anomaly and swift hatchery interventions succeed, the outbreak’s “summer tail” may be heavily truncated, preventing the final count from mirroring the most extreme historical boom years.
Question: How many cases will the CDC report in the 2026 backyard poultry Salmonella investigation? Final Prediction: Probability distribution:
Total Cost: extra_metadata_in_explanation is disabled Time Spent: extra_metadata_in_explanation is disabled LLMs: extra_metadata_in_explanation is disabled Bot Name: extra_metadata_in_explanation is disabled
Forecaster 1: Probability distribution:
Forecaster 2: Probability distribution:
Forecaster 3: Probability distribution:
The research reports that as of May 14–15, 2026 there were 184 confirmed Salmonella cases across 31 U.S. states linked to backyard poultry, with 53 hospitalizations and 1 death. Three strains are involved (Saintpaul: 133 cases; Enteritidis: 32; Mbandaka: 19), with illness onset dates from January 17 through April 20, 2026. The outbreak accelerated sharply in late April–early May (34 cases Apr 13–23 to 184 cases by May 4), coinciding with the spring peak in backyard poultry purchases; 78% of interviewed patients reported poultry contact and 87% of poultry owners acquired birds since Jan 1, 2026. The investigation has identified five implicated hatcheries and an unusual association with Pekin ducks, and isolates show multiple antibiotic resistances.
For forecasting, the research compares recent multi-state backyard poultry outbreaks (historical totals roughly 470–1,230 cases, with a 2025 outbreak of 559 cases) and proposes reference-class scenarios: conservative 200–300, moderate 400–600, historical-average 600–900, and severe 1,000–1,300 cases. Factors pushing counts higher include seasonality, multiple hatchery sources, underreporting and reporting lags, rapid recent growth, and high rates among young children; mitigating factors include media/CDC warnings and hatchery interventions. A key uncertainty is whether the late-April surge reflects ongoing spread or a reporting catch-up tied to illness onset dates through April 20.
Sources used in the research: the document cites 26 numbered references ([1]–[26]) including CDC outbreak updates, state health department reports, hatchery/industry data, and news coverage. No verbatim URLs were provided in the research, so I cannot copy links here.
The most recent data shows 184 confirmed cases across 31 states, with 53 hospitalizations (34% hospitalization rate) and 1 death in Washington state [4][11][15][16]. The outbreak involves three concurrent Salmonella strains:
The outbreak began on January 17, 2026, with illness onset dates ranging through April 20, 2026 [16][18].
The outbreak shows a concerning acceleration pattern:
This rapid escalation coincides with the spring poultry purchasing season, when backyard poultry ownership peaks [18][23].
Recent comparable outbreaks:
Average historical range: 470-1,230 cases for multi-state backyard poultry outbreaks, with the 2025 outbreak at 559 cases serving as the most recent comparable baseline.
Vulnerable populations:
Exposure patterns:
Unusual characteristics:
Factors suggesting higher final counts:
Factors suggesting stabilization:
No active prediction markets were identified for this specific question on major platforms (Metaculus, Manifold, Polymarket). This appears to be a specialized public health forecasting question without current market-based predictions available.
Reference class analysis:
Current trajectory analysis: The outbreak added 150 cases over approximately 11 days in late April/early May. If growth continues at even a fraction of this rate through June-July (peak season), the final count could easily exceed 500 cases. However, the 3-4 week reporting lag means cases reported in mid-May may reflect exposures from mid-to-late April [6][26].
Key uncertainty: Whether the rapid acceleration from April 23-May 4 represents the true peak of the outbreak or merely a catch-up in reporting delayed cases. The illness onset dates through April 20 [16] suggest the exposure wave may already be cresting, but continued poultry sales through summer could drive additional cases.
Conditional on the question not being annulled, and assuming it resolves on the final CDC investigation count rather than a near-term snapshot:
(a) Time left until outcome is known.
The prompt does not provide a resolution date. The CDC page is still marked Open as of its May 14, 2026 update, so if this resolves at final CDC closure, I would expect the outcome to become known in roughly 4–6 months—analogous backyard-poultry investigations closed in late September or October in 2023–2025. If the platform has an unstated near-term resolution date, the forecast should shift sharply toward the current 184 cases. (cdc.gov)
(b) Outside view.
The relevant reference class is CDC annual/multistate backyard-poultry Salmonella investigations. From 2015–2022, CDC-linked research reports 88 multistate backyard-poultry-associated outbreaks and 7866 outbreak-associated illnesses, averaging about 983 illnesses per year if aggregated annually, though individual outbreak-strain counts are smaller. Recent annual CDC pages resolved at 1072 cases in 2023, 470 cases in 2024, and 559 cases in 2025. Early-to-final multipliers are large: 2023 went from 104 cases as of May 8 to 1072 final; 2024 from 109 as of May 16 to 470 final; 2025 from 104 as of May 19 to 559 final. (stacks.cdc.gov)
(c) Inside view.
The current CDC Fast Facts figure is 184 cases, and the investigation includes three outbreak strains across 31 states, with illness-onset dates through April 20 and a CDC-noted 3–4 week reporting lag. The May 14 update added 150 illnesses and added Enteritidis and Mbandaka to Saintpaul, so some of the “growth” is case-definition/strain inclusion rather than pure new incidence. Still, 184 cases by May 4 is a fairly high early-season count, and the investigation has already linked strains to five hatcheries, with 87% of poultry-owning interviewed patients reporting poultry obtained since January 1. (cdc.gov)
(d) Outcome if nothing changed.
184 cases.
(e) Outcome if the current trend continued.
Naively extending the rise from 34 cases as of April 13 to 184 as of May 4—about 150 added over 21 “as-of” days—would put a final count around 900–1200 if substantial reporting continues into late summer. I discount this because the jump partly reflects adding two outbreak strains. (cdc.gov)
(f) Expectations of experts and markets.
CDC does not publish a final-count forecast. The research assistant found no liquid prediction market. The question creator’s apparent expectation of “likely not higher than 211” is important as a warning that the intended resolution might be near-term, but it is hard to reconcile with historical final CDC counts unless the question resolves soon rather than at closure.
(g) Unexpected low scenario.
The May 14 jump was mostly backfill and strain reclassification; public-health messaging and hatchery/store interventions stop the exposure chain quickly; CDC either posts no further update before resolution or only adds a few late-linked cases. Final/settlement: 184–250.
(h) Unexpected high scenario.
Additional serotypes or hatcheries are added, summer backyard-poultry contacts continue, and WGS surveillance links many otherwise-unexposed cases to outbreak strains. Final count exceeds the recent 2023 level and lands above 1500.
Rationale.
Anchoring on the outside view, a “normal” final CDC backyard-poultry Salmonella investigation is not near 184; recent resolved annual pages are clustered around 500–1100+ cases. The 2026 count is already higher, earlier, than comparable 2024–2025 early updates, and the CDC’s reporting lag plus multi-hatchery evidence push me upward. Offsetting that, the large May jump includes newly added strains, the investigation currently has fewer strains than some high-count years, and the question creator’s low upper expectation suggests a nontrivial chance the intended resolution is a near-term snapshot. My median is therefore below a pure historical-multiplier extrapolation but well above 211.
Percentile 0.1: 184.1 Percentile 1: 186.1 Percentile 5: 220.1 Percentile 10: 310.1 Percentile 20: 460.1 Percentile 30: 570.1 Percentile 40: 690.1 Percentile 50: 820.1 Percentile 60: 950.1 Percentile 70: 1110.1 Percentile 80: 1320.1 Percentile 90: 1620.1 Percentile 95: 1900.1 Percentile 99: 2550.1 Percentile 99.9: 3500.1
Assumption: I am forecasting the final CDC cumulative case count for this 2026 backyard-poultry Salmonella investigation, not merely the next update. If the question instead resolves on a near-term fixed date before CDC posts another substantive update, the forecast should be much closer to 184.
(a) Time left until outcome is known.
The CDC investigation is still marked Open as of the May 14, 2026 update, and similar backyard-poultry investigations in 2024 and 2025 closed in late September/October. So I expect the final resolving value to be known in roughly 4–5 months, around late September to October 2026, though CDC could update/close earlier or later. (cdc.gov)
(b) Outside view.
The relevant reference class is annual CDC multistate Salmonella outbreak investigations linked to backyard poultry. CDC’s 2015–2022 review found 88 multistate backyard-poultry-associated outbreaks and 7,866 illnesses, with annual totals ranging from 255 to 1,722 and a median annual total around 1,100 in that period; 2023 was 1,072, 2024 was 470, and 2025 was 559. Recent years therefore suggest a “typical” final value in the 500–1,100 range, with a long high tail. (stacks.cdc.gov)
(c) Inside view.
The current CDC Fast Facts count is 184 cases across 31 states, with 53 hospitalizations and 1 death; the latest detailed update says those 184 cases were as of May 4, 2026, with illness onsets from January 17 to April 20, and CDC notes that recent illnesses may take 3–4 weeks to determine as part of the outbreak. This makes 184 a floor, not a good estimate of the final count. (cdc.gov)
Specifics push me above the creator’s suggested “likely not higher than 211”: the count jumped by 150 since the April 23 update, now includes three outbreak strains, and the strains have been linked to 5 hatcheries; of interviewed patients, 78% reported backyard-poultry contact, and 87% of owners with data acquired poultry since January 1, 2026. Those are features of a broad seasonal/source-linked investigation, not an almost-over cluster. (cdc.gov)
Against that, the jump partly reflects retrospective inclusion of two additional serotypes and reporting catch-up, so I do not extrapolate the +150 literally. I also give weight to 2024 and 2025 being lower than the 2019–2023 high period: 2024 ended at 470 after being 109 at the May update and 195 at the June update, while 2025 ended at 559 after being 104 at the May update and 187 at the June update. (cdc.gov)
(d) Outcome if nothing changed.
If CDC made no further numerical update, the resolving count would be 184 cases.
(e) Outcome if the current trend continued.
A naive continuation of the recent reporting burst—34 as of April 13 to 184 as of May 4—would imply a final count well over 1,000 cases by late summer/fall. I discount that heavily because the +150 included adding new outbreak strains and lagged reports, not just new forward incidence. (cdc.gov)
(f) Expectations of experts and markets.
CDC does not publish a numeric forecast, but its expert guidance is directionally upward: it says the true number of sick people is likely much higher than reported and that recent illnesses may not yet be reported because classification usually takes 3–4 weeks. I did not find a liquid public prediction market for this exact count; the question creator’s “likely not higher than 211” is therefore a soft prior, but I think it is too low if this resolves to the final investigation count. (cdc.gov)
(g) Unexpected low scenario.
The low case is that the May 14 update already captured nearly all related cases, the additional serotypes were mostly retrospective, hatchery/store interventions stop new exposure quickly, and CDC closes with only a small lagged addition—say 190–250 cases.
(h) Unexpected high scenario.
The high case is that more serotypes or hatcheries are added, contaminated chick/duckling supply continues through peak backyard-poultry season, and the investigation behaves more like 2020–2023, producing 1,200+ and possibly 1,700+ reported cases. (archive.cdc.gov)
Rationale.
I start from the outside-view base rate: recent CDC backyard-poultry annual investigations commonly end in the several-hundred to low-thousand range. The 2024 and 2025 final counts, 470 and 559, are the most relevant recent anchors, but the current 2026 count of 184 as of May 4 is already around the June-level counts from those two years, despite still having multiple weeks of reporting lag and much of spring/summer ahead. That moves my median above 2024/2025, but below the 2019–2023 median because the recent trend has been lower and because the May surge probably includes catch-up and expanded strain definition. My median is therefore about 670 cases, with a meaningful low tail near 184–250 if the investigation rapidly stalls, and a substantial high tail above 1,000 if additional strains/sources are added.
Percentile 0.1: 184.1
Percentile 1: 186.1
Percentile 5: 211.4
Percentile 10: 265.4
Percentile 20: 350.4
Percentile 30: 445.4
Percentile 40: 555.4
Percentile 50: 670.4
Percentile 60: 790.4
Percentile 70: 925.4
Percentile 80: 1085.4
Percentile 90: 1320.4
Percentile 95: 1510.4
Percentile 99: 1875.4
Percentile 99.9: 2325.4
Conditioned on the question not being annulled, and assuming resolution is to the final cumulative CDC case count for this 2026 investigation rather than a near-term fixed-date snapshot.
(a) Time left until outcome is known. No explicit resolution date was provided. If this resolves when CDC closes the annual backyard-poultry investigation, the likely time left is about 4–5 months: recent comparable CDC pages closed on Sept. 29, 2025 and Oct. 22, 2024, so from May 25, 2026 I would expect final knowledge around late September to October 2026. (cdc.gov)
(b) Outside view. The relevant reference class is annual CDC multistate backyard-poultry Salmonella outbreak pages aggregating multiple outbreak strains. From 2015–2022, annual case totals ranged from 255 to 1,722, with 2020 at 1,722, 2021 at 1,135, and 2022 at 1,230; CDC’s analysis also notes 2019–2022 averaged 1,316 illnesses/year. More recent final annual pages were lower: 470 cases in 2024 and 559 cases in 2025. (stacks.cdc.gov)
(c) Inside view. The current 2026 page is already at 184 cases, 53 hospitalizations, 1 death, and 31 states, with the investigation still open. The May 14 update says 150 new illnesses were added since April 23, the count is based on data as of May 4, illnesses began through April 20, and CDC warns that recent illnesses can take 3–4 weeks to classify. The outbreak also involves three strains and has been linked to five hatcheries, with 87% of interviewed poultry owners having obtained poultry since Jan. 1, 2026. These facts push me materially above the creator’s 211-ish anchor for a final-count forecast. (cdc.gov)
(d) Outcome if nothing changed. 184 cases: if no further numerical CDC update appeared before resolution, the Fast Facts “Cases: 184” would control. (cdc.gov)
(e) Outcome if the current trend continued. From 34 cases as of April 13 to 184 cases as of May 4 is +150 over about 3 weeks; one more comparable reporting increment would imply roughly 330–350 cases, and a sustained spring/summer continuation would imply roughly 900–1,100 cases before closure. I do not expect a straight-line continuation all summer, but it defines the high-side pull. (cdc.gov)
(f) Expectations of experts and markets. CDC provides no numerical forecast. The supplied research says no active prediction markets were found; my own search did not turn up a reliable market signal. The only explicit outside numeric expectation in the prompt is the creator’s view that the number is likely not higher than 211, which I treat as a weak/possibly short-horizon anchor, not as persuasive for a final annual count.
(g) Unexpected low scenario. The May 14 jump was mostly a one-time WGS/reclassification catch-up; the contaminated hatchery lots have already cleared retail channels; CDC and state interventions sharply reduce new exposures; the page closes after only a small number of additional linked cases, ending around 190–250.
(h) Unexpected high scenario. Additional hatcheries or upstream suppliers are implicated, more serotypes are added as in 2025, and spring/summer poultry sales continue seeding infections while reporting lag fills in. In that scenario, 2026 could resemble the larger 2019–2022 years and exceed 1,000 cases.
Rationale. I anchor on the annual CDC backyard-poultry reference class rather than on a single strain, because the resolution criterion uses the cumulative case count on the 2026 CDC page, and the current page is explicitly aggregating multiple outbreak strains. The long-run annual base rate is high—often several hundred to over a thousand cases—but the two most recent completed years, 2024 and 2025, suggest a more moderate modern baseline around 500–600. The 2026 inside view then moves me upward: 184 cases by data cutoff May 4 is already well ahead of the 2025 trajectory at a comparable early stage, and the 3–4 week reporting lag means more cases are probably already “baked in.” I still put meaningful mass below 300 because the creator’s ≤211 anchor, public warnings, and hatchery interventions could mean the May 14 update was mostly catch-up rather than a durable growth rate. My median is therefore around 610 cases, with a wide right tail.
Percentile 0.1: 184.1
Percentile 1: 186.1
Percentile 5: 199.6
Percentile 10: 223.4
Percentile 20: 315.4
Percentile 30: 410.4
Percentile 40: 505.4
Percentile 50: 610.4
Percentile 60: 720.4
Percentile 70: 850.4
Percentile 80: 1000.4
Percentile 90: 1240.4
Percentile 95: 1475.4
Percentile 99: 1900.4
Percentile 99.9: 2550.4
Agent Forecast (discrete, confidence: medium)
Base Rate: 2025 CDC backyard poultry Salmonella outbreak grew from 7 → 559 cases over 5 months with per-update increments of 100–242 cases. 2024 reached 470 final. Current outbreak is mid-trajectory at 184; significant further growth is likely if resolution extends past the next CDC update.
Initial Reasoning:
As of today (May 25, 2026), the CDC Fast Facts section on the exact specified URL shows 184 cases (May 14, 2026 update, data through May 4).
As of May 25, 2026, the CDC outbreak page shows exactly 184 cases in the Fast Facts s
Key Uncertainties:
Evidence Sources (6):
Grounding Facts (passed to reviewers):
Draft: 184: 45.6%, 212+: 43.3%, 185: 0.5%, 186: 0.5%, 187: 0.5%
Reviewer Panel:
Reviewer (reasoning)
The draft’s main flaw is treating the resolution date as if it could fall after the next CDC update. By the criteria, resolution is based on the snapshot as of today (May 25, 2026), and the most recent update (May 14) reports 184 cases. There is no room for a post-dated update to count. All uncertainty about future updates is irrelevant.
Objections:
Reviewer (calibration)
The forecast’s bimodal distribution is critically dependent on an implicit assumption about the resolution date’s timing relative to the next CDC update. Without a specified resolution date, the probabilities assigned to these two scenarios are speculative and lack a clear basis. The forecast also relies on an ‘analogous 2025 investigation’ without detailing its relevance, making the comparison less robust.
Objections:
Reviewer (fact-checker)
Verdict: clean
Adjustment Rationale:
Holding firm on the bimodal interpretation against the reasoning reviewer, who incorrectly assumed resolution = today (May 25, 2026); the resolution criteria do not specify a resolution date, and treating today as the snapshot date is not supported. The calibration reviewer’s milder point — that 184 may be slightly too high given an open investigation with a near-term expected update — is partially absorbed by reconciling across the three draft trajectories (which ranged 0.35–0.57 on 184). Final split: 184 at 0.40 (probability the resolution date precedes the next CDC update ~June 4–7), 212+ at 0.465 (probability resolution is later; given +150 in the prior update cycle, late-April illness cases still in the reporting pipeline, and a 2025 analog that grew to 559, growth past 212 is the dominant post-update outcome), and the middle bins 185–211 each at 0.005 reflecting the fact that CDC publishes updates in large batches (50+ cases), making small increments inconsistent with publication practice. Fact-checker verdict was clean.
forecast_sdk | 330.5s | research $1.4143 + reviewers $0.0086 + reconcile $0.1953 = $1.6556
Median (P50): ~340 cases
Current floor is 184 cases (as of May 4, 2026). The CDC’s 3–4 week reporting lag means illnesses from late April and all of May are not yet reflected in this count, creating substantial upward pressure over the remaining 58 days.
2026 outbreak is ahead of 2025’s pace. The 2025 outbreak had ~104 cases by late May and reached 559 by September. The 2026 outbreak already stands at 184 by early May—earlier and higher—suggesting a faster or larger trajectory. Interpolating 2025’s mid-July position (~300–350 cases) and adjusting for the 2026 head start points to 340–380 cases by July 22.
Multi-strain structure and hatchery linkages amplify growth. The investigation combines three Salmonella strains (Saintpaul, Enteritidis, Mbandaka) across five linked hatcheries, with CDC noting additional hatcheries may be linked. Each new hatchery linkage can trigger retroactive case additions; historical updates have added 80–240 cases in single batches.
Seasonal peak and update cycles favor continued growth. Spring chick-purchasing season drives ongoing exposure through June–August. The CDC typically publishes updates every 1–2 weeks; with 58 days remaining and no indication of investigation closure, multiple update cycles will occur before July 22.
Right-skewed distribution reflects substantial upside tail. While rapid containment (184–210 cases) is possible (~8% probability), the modal scenario is continued moderate-to-strong growth. Historical backyard poultry outbreaks in 2022–2024 reached 470–1,230 cases; a
Forecast (percentiles, aggregated):
Per-model forecasts:
Rationale: Summary The baseline for this estimate is the 184 cases already reported by the CDC across 31 states as of mid-May 2026. This outbreak, involving three concurrent Salmonella strains (Enteritidis, Mbandaka, Saintpaul) linked to multiple hatcheries, is growing at an exceptionally rapid pace. Between late April and mid-May, 150 new cases were added in a span of just three weeks. When compared to similar backyard poultry outbreaks, the 2026 event is tracking significantly ahead of schedule; outbreaks in 2024 and 2025 only reached roughly 104 to 109 cases by late May. Historically, Salmonella cases tied to backyard poultry surge during the spring and summer as chick purchasing peaks. In previous years, reported case counts have roughly doubled between late May and late June, and more than doubled again by late August. Applying this established historical growth trajectory to the elevated 2026 baseline points to a much higher final case count. Because the cumulative count can only increase, the absolute floor is 184. The most likely outcome depends on the timing of the final CDC update before the July 22 resolution date. An update in late June would likely push the count into the low-to-mid 300s, while a mid-July update could easily elevate the total near or above 500 cases, centering the estimate around 395 cases.
Strongest Arguments for Higher Values
Strongest Arguments for Lower Values
Key Uncertainties
CDC’s current outbreak page, last updated May 14, 2026, reports 184 cases, 53 hospitalizations, 1 death, and 31 affected states. The linked investigation page adds that those 184 cases were counted as of May 4, 2026; illness onsets ranged from January 17 to April 20, 2026; 150 illnesses were added since the prior April 23 update; three serotypes are already included; and five hatcheries have already been linked. CDC also notes that reporting lag is usually 3 to 4 weeks. (cdc.gov)
That combination makes a final total at or below 211 very unlikely. To resolve at 211 or lower, the CDC total would have to add no more than 27 cases beyond a May 4 count of 184, despite the fact that the investigation had already grown from 34 cases as of April 13 to 184 as of May 4 and despite the explicit 3 to 4 week reporting lag, which means late-April and early-May illnesses were still incompletely captured when the page was updated. (cdc.gov)
Recent CDC backyard-poultry investigations point the same way. The 2023 page rose from 104 cases as of May 8 to a final 1,072; the 2024 page rose from 109 cases as of May 16 to a final 470; the 2025 page rose from 104 cases as of May 19 to a final 559; and the 2021 page rose from 163 cases as of May 20 to a final 1,135. Even the smallest of those recent early-season-to-final multipliers would place a 184-case starting point far above 211, although I treat that benchmark cautiously because surveillance and outbreak composition differ year to year. (cdc.gov)
Longer-run CDC evidence is also supportive. In CDC’s 2015–2022 study of backyard-poultry-associated salmonellosis, there were 88 multistate outbreaks and 7,866 illnesses, and most illness onsets occurred in April (23%) or May (24%). That means an investigation whose counted onsets only run through April 20 is, historically, still early relative to the main seasonal window. Recent annual CDC backyard-poultry investigations have also typically remained open until fall rather than ending in May. (stacks.cdc.gov)
My practical forecast is therefore that almost all probability belongs in the >211 bucket. I still leave a small residual tail on 184 through 211 for paths where transmission drops abruptly, later case finding is unusually sparse, or CDC stops updating the page earlier than its recent pattern. To express that low tail smoothly, the code assigns 1.2% total mass across 184 to 211 using a truncated Poisson shape over additional cases beyond 184; the remaining 98.8% goes to >211. My implied unconstrained central estimate is far above 211, so the key judgment here is not where within 184 to 211 the total lands, but whether the outbreak can stay that low at all. My answer is: probably not.
As of the CDC’s May 14, 2026 update, the backyard-poultry Salmonella investigation is still open and the Fast Facts box shows 184 cases, 53 hospitalizations, 1 death, and 31 states. The detailed investigation page says those 184 cases reflect illnesses with onset from January 17, 2026 through April 20, 2026; 150 illnesses were added since the April 23, 2026 update; the investigation now spans three serotypes; and the outbreak strains have already been linked to 5 hatcheries. CDC also says it usually takes 3 to 4 weeks to determine whether a sick person is part of an outbreak. Because today is May 25, 2026, the published count likely still misses some later-onset illnesses even before the summer backyard-poultry season fully plays out. (cdc.gov)
The historical base rate makes 211 look far too low. In CDC’s 2015–2022 backyard-poultry review, annual totals ranged from 255 to 1,722 cases, with a median of 1,072. The subsequent CDC outbreak pages then finished at 1,072 cases in 2023, 470 in 2024, and 559 in 2025. So the lowest full-year final total I found from 2015 through 2025 was 255, already above 211. (stacks.cdc.gov)
Comparable spring snapshots point the same way. CDC reported 163 cases on May 20, 2021 before finishing at 1,135; 219 on June 2, 2022 before 1,230; 104 on May 8, 2023 before 1,072; 109 on May 16, 2024 before 470; and 104 on May 19, 2025 before 559. The weakest of those analogs is 2024, where the final was still about 4.31 times the mid-May count. Applying even that weakest recent multiplier to the current 184 gives roughly 793 final cases, so resolving at 211 or lower would require 2026 to break sharply below every comparable recent pattern. (archive.cdc.gov)
Because the question’s explicit bins stop at 211, the practical forecasting problem is mostly how much probability to leave below that threshold. I therefore use a deliberately conservative mixture model. The main scenario, with 97.8% weight, is a broad typical-season outcome centered around roughly 930 final cases overall. I still reserve a 2.2% low-growth scenario for the possibility that ascertainment is already unusually complete and only a small backlog plus short tail remains. That keeps the first bin at 0.0 per the question rules, spreads a small amount of mass across exact outcomes 184 through 211, and places the rest on greater than 211. In plain language: I think the CDC final count is overwhelmingly likely to end above 211, with only a small residual chance that the investigation stalls out near the current level. This final paragraph is an inference from the current CDC situation, the CDC reporting-lag note, and the historical analogs above. (cdc.gov)
As of the CDC’s May 14, 2026 update, the backyard-poultry outbreak page reports 184 cases across 31 states, with the investigation still open. CDC says those reported illnesses began between January 17, 2026 and April 20, 2026, and notes that it usually takes 3 to 4 weeks to determine whether a sick person is part of the outbreak. The same update says the 184 cases already span three outbreak strains and that the strains have been linked to 5 hatcheries. That combination matters because it means the currently published total is both early in the seasonal window and still subject to ordinary reporting lag. (cdc.gov)
CDC’s 2023 multistate enteric-outbreak summary says that backyard-poultry Salmonella illnesses usually occur mostly between April and August. Since the current 2026 case count only includes illnesses through April 20, 2026, a large part of the usual illness window is still ahead of the latest onset date currently reflected on the page. (cdc.gov)
The strongest evidence against a finish at 211 or below is the history of recent CDC backyard-poultry pages. Close analogs all rose far above 211 after similar springtime starting points: 2021 finished at 1,135 after 163 cases by May 20; 2023 finished at 1,072 after 104 cases by May 8; 2024 finished at 470 after 109 cases by May 16; 2025 finished at 559 after 104 cases by May 19; and even the later-starting 2022 investigation finished at 1,230 after 219 cases by June 2. (archive.cdc.gov)
Put differently, those analog years added at least 361 more cases after their early-season counts, and some added around 1,000 more. I do not assume 2026 must repeat the very large 2021-2023 outcomes, because the more recent 2024 and 2025 investigations closed much lower than those peak years. Still, even a conservative blend of recent analogs implies a final total far above 211. So, for the narrow bins requested here, my judgment is that the only realistic debate is how much probability to leave for an unusually abrupt stall or a process surprise. I therefore place 98.8% probability on the final CDC total being greater than 211, and spread the remaining 1.2% across 184-211, with the small nonzero mass representing a very unlikely near-flat ending. This is an inference from the cited CDC current-page data, seasonality, reporting-lag note, and historical analog pages. (cdc.gov)
Because the prompt does not give a separate earlier resolution date, I interpret this as the eventual final cumulative case count on the CDC’s 2026 backyard-poultry outbreak page. The CDC page currently reports 184 total cases as of May 4, 2026, across three serotypes (Saintpaul, Enteritidis, and Mbandaka) and 31 states; illness onsets run from January 17, 2026, to April 20, 2026, and CDC explicitly notes that reporting usually lags by 3–4 weeks. (cdc.gov)
The key threshold here is 211. Staying at 211 or lower would allow only 27 additional cases beyond the current 184. That looks unlikely. The previous CDC update had only 34 cases as of April 13, 2026, so the May 14, 2026 update added 150 cases and two new serotypes in a single revision. The same update says the outbreak strains have already been linked to 5 hatcheries and that additional hatcheries may still be linked as the investigation continues. (cdc.gov)
A conservative near-term analogue already points above 211. In 2024, CDC’s backyard-poultry page went from 109 cases as of May 16, 2024, to 195 cases as of June 20, 2024, an increase of 86. In 2025, it went from 104 cases as of May 19, 2025, to 187 cases as of June 23, 2025, an increase of 83. If 2026 followed only those relatively modest recent trajectories, the current 184 would project to roughly the high 260s by late June 2026, comfortably above 211. (cdc.gov)
The longer-run seasonal base rate is even stronger. Every comparable CDC backyard-poultry investigation I checked from 2015 onward finished above 211 cases: 252 in 2015, 334 in 2018, 1,120 in 2017, 1,134 in 2019, 1,722 in 2020, 1,135 in 2021, 1,230 in 2022, 1,072 in 2023, 470 in 2024, and 559 in 2025. (archive.cdc.gov) Even the two mildest analogues, 2015 and 2018, still finished above 211 despite having only 181 cases by June 29, 2015, and 212 cases by July 20, 2018. (archive.cdc.gov) Since 2026 is already at 184 cases by an earlier point in the calendar, those low-end analogues still imply a final total above 211.
So my bottom line is that the CDC eventually reporting more than 211 cases on this 2026 backyard-poultry page is overwhelmingly more likely than not. I leave a small residual probability for an unexpectedly abrupt stop in case accrual, administrative quirks in how CDC updates the page, or ambiguity in the omitted resolution timing. Within that small under-212 tail, I center mass around totals near 200, representing a scenario where only a limited number of lagged cases are added before the page effectively stops moving. My forecast is 98.0% on >211 overall.
As of Monday, May 25, 2026, the most recent CDC update on the specified backyard-poultry outbreak page is dated May 14, 2026. The page is still marked open, and its Fast Facts section lists Cases: 184 (New: 150), Hospitalizations: 53, Deaths: 1, and States: 31. Under the resolution rules, that Fast Facts cases figure is the operative current count. (cdc.gov)
The detailed epidemiology section says those 184 reported cases correspond to illnesses with onset from January 17, 2026 through April 20, 2026. CDC also says recent illnesses may not yet be reported because it usually takes 3 to 4 weeks to determine whether a sick person is part of an outbreak, and it says the outbreak strains have already been linked to 5 hatcheries with additional hatcheries potentially still to be identified. That combination strongly suggests the current count is still early, not near final. (cdc.gov)
Seasonality points the same way. CDC’s 2023 multistate outbreak summary says backyard-poultry Salmonella outbreaks are investigated every year and that most illnesses occur between April and August. A CDC-backed review of 2015-2022 found 88 multistate backyard-poultry-associated outbreaks causing 7,866 illnesses, so large cumulative totals are a normal feature of this exposure category rather than an outlier. (cdc.gov)
The clearest evidence comes from directly comparable CDC pages. In 2023, CDC went from 104 cases on May 8 to 1,072 final cases on October 19. In 2024, it went from 109 cases on May 16 to 470 final cases. In 2025, it went from 104 cases on May 19 to 559 final cases. (cdc.gov) Older high years were even larger: 219 cases on June 2, 2022 eventually became 1,230 final cases; 2021 closed at 1,135 cases; and 2020 closed at 1,722. Those analogs imply end/current multipliers far above the roughly 1.15x multiplier that would be needed for 2026 to finish at 211 or lower. (cdc.gov)
For the forecast itself, I use a cautious mixture model on the final/current multiplier rather than a single extrapolation. The low, base, and high scenarios have median multipliers of 2.9x, 4.9x, and 7.8x, chosen to bracket the recent lower years (2024-2025), the stronger 2022-2023 pattern, and the fact that 2026 is already at 184 cases across 31 states at an earlier point in the seasonal window. That produces a central tendency around the high hundreds to roughly 1,000 final cases, but because the scoring bins collapse everything above 211 into one bucket, the main practical conclusion is simply that almost all of the mass belongs in >211. (cdc.gov)
So I assign overwhelming probability to the final CDC total ending above 211. I leave only a tiny residual mass on 184-211 to cover extreme process risk, such as an unusual change in CDC aggregation or reporting on the page, or some other unforeseen resolution artifact.