{
  "slug": "us-local-dengue",
  "question": "What are the odds of catching dengue without leaving the continental US?",
  "category": "health",
  "tags": [
    "household"
  ],
  "no_reliable_estimate": false,
  "perceived": {
    "description": "Most US residents file dengue under 'tropical travel disease' and assume zero risk while staying home. No published survey measures fear of catching dengue domestically, so this is an intuition read: the perceived domestic risk is effectively zero for nearly everyone, which understates the small but rising local-transmission risk in a few southern states and overstates the near-zero risk everywhere else. The mismatch is one of category error rather than magnitude.",
    "rough_estimate": "≈ 0 (assumed to be a travel-only disease)",
    "kind": "intuition"
  },
  "native": {
    "display": "105 locally-acquired cases among ~338 million continental US residents in 2024",
    "numerator": 105,
    "denominator": 338000000,
    "unit": "locally-acquired dengue cases per continental US resident per year (2024)",
    "population": "Residents of the 48 contiguous US states + DC, 2024"
  },
  "normalized": {
    "lifetime_us_adult": 0.000015,
    "display": "~1 in 67,000 over a lifetime",
    "log_value": -4.82,
    "assumptions": "Subgroup = a person residing in the continental US (48 states + DC); horizon = 59-year remaining adult life (site default from age 18). Headline counts a DIAGNOSED clinical dengue case, not infection (40-80% of dengue infections are asymptomatic and many symptomatic cases go untested, so true infection risk is higher — this pushes the high bound up). Base annual rate from CDC MMWR 2024: 105 locally-acquired cases (Florida 85, California 18, Texas 2) / ~338M continental US residents = 3.1e-7 per person-year. Compounded over 59 years: 1-(1-3.1e-7)^59 = 1.83e-5 (~1 in 54,600), which is the 2024-RECORD-YEAR rate. 2024 was a +359% peak; before 2023 continental local transmission was near-zero in most years. Point estimate is set slightly BELOW the 2024-only figure at 1.5e-5 (~1 in 67,000) to average the recent peak against the much lower historical baseline, while leaning toward persistence because the entry's whole premise — Aedes range expansion and warming — is an upward trend. Low bound 1.5e-6 reflects pre-2023 near-zero local-transmission years (~10x below 2024). High bound 1.5e-4 reflects clinical undercount plus a worsening-transmission scenario (~10x above 2024). The 2-order-of-magnitude band is honest about a volatile, geographically concentrated, expanding risk rather than falsely precise.",
    "uncertainty": {
      "low": 0.0000015,
      "high": 0.00015
    },
    "scope": "subgroup_lifetime"
  },
  "sources": [
    {
      "url": "https://www.cdc.gov/mmwr/volumes/75/wr/mm7518a1.htm",
      "title": "Increase in Travel-Associated and Locally Acquired Dengue Cases — United States, 2024",
      "publisher": "CDC Morbidity and Mortality Weekly Report (MMWR)",
      "source_type": "govt_report",
      "statistic": "3,798 total US dengue cases in 2024 (+359% above the 2010–2023 average); 97.2% travel-associated, 2.8% locally acquired; continental US locally-acquired cases: Florida 85 (10 counties), California 18 (3 counties), Texas 2 (2 counties) = 105.",
      "excerpt": "During 2024, a record 3,798 dengue cases were reported [...] a 359% increase above the 2010–2023 annual average. Among these 3,798 cases, 97.2% were associated with travel outside the reporting jurisdiction during the 2 weeks preceding symptom onset; the remaining 2.8% were locally acquired. [...] Three jurisdictions reported locally acquired cases, including Florida (85 cases reported from 10 counties), California (18 from three counties), and Texas (two from two counties).",
      "source_date": "2026-05-14",
      "source_accessed": "2026-06-13",
      "calculation_notes": "Locally-acquired continental total = 85+18+2 = 105. Annual rate = 105 / 338,000,000 continental residents = 3.1e-7/person-year. 59-year compounded = 1-(1-3.1e-7)^59 = 1.83e-5. This is the authoritative FINAL count; an earlier CDC HAN (March 2025) listed Florida as 91 preliminarily — the MMWR's 85 supersedes it."
    },
    {
      "url": "https://wwwnc.cdc.gov/eid/article/32/5/25-1812_article",
      "title": "Investigation of and Response to Autochthonous Dengue, Los Angeles County, California, USA, August–November 2024",
      "publisher": "CDC Emerging Infectious Diseases",
      "source_type": "peer_reviewed",
      "statistic": "14 locally-acquired dengue cases in LA County Aug–Nov 2024, geographically clustered (some within a 1-mile radius over 7 weeks), consistent with focal local transmission rather than diffuse community spread.",
      "excerpt": "During August–November 2024, a total of 14 locally acquired cases of dengue were identified in Los Angeles County, California, USA. [...] All 6 cases were identified within a 1-mile radius over a 7-week period, consistent with an outbreak involving ongoing local transmission.",
      "source_date": "2026-05-06",
      "source_accessed": "2026-06-13",
      "calculation_notes": "Grounds the regional_breakdown claim that California's 18 cases were not statewide-uniform but concentrated in a few LA-area clusters. Supports treating local dengue as a focal/neighborhood risk, not a flat per-capita state rate.",
      "independence_note": "Same publisher family (CDC) as the MMWR source but a distinct peer-reviewed field investigation with separate authors and data."
    },
    {
      "url": "https://www.cdc.gov/han/php/notices/han00523.html",
      "title": "Ongoing Risk of Dengue Virus Infections and Updated Testing Recommendations in the United States",
      "publisher": "CDC Health Alert Network (HAN)",
      "source_type": "govt_report",
      "statistic": "CDC advisory that dengue activity remained high into 2025 and that spring/summer raise both travel-associated and locally-acquired risk; 2024 local cases listed as Florida 91 (preliminary), California 18, Texas 1.",
      "excerpt": "Dengue activity remains high in some parts of the United States [...] Spring and summer travel coincide with the peak season for dengue in many countries, increasing the risk of both travel-associated and locally acquired cases.",
      "source_date": "2025-03-18",
      "source_accessed": "2026-06-13",
      "calculation_notes": "Used to establish that the risk is ongoing/elevated rather than a one-off 2024 spike, supporting the upward-trend framing. Its preliminary Florida count (91) differs from the MMWR final (85); the entry uses the MMWR figure and flags the discrepancy in assumptions."
    },
    {
      "url": "https://www.cidrap.umn.edu/dengue/us-dengue-cases-jumped-359-2024-amid-global-surge",
      "title": "US dengue cases jumped 359% in 2024 amid global surge",
      "publisher": "CIDRAP, University of Minnesota",
      "source_type": "reputable_reference",
      "statistic": "Confirms 3,798 total cases, 359% increase, 2.8% locally acquired, 105 locally-acquired nationwide with Florida 85 (81%); notes Aedes aegypti and albopictus are established across the southeastern/southwestern US and continue to spread as temperatures rise.",
      "excerpt": "Florida accounting for 85 of the 105 locally acquired cases (81%) reported nationwide [...] Ae aegypti and albopictus mosquitoes are found throughout large areas of the southeastern and southwestern United States and continue to spread to other regions [...] Vector presence and distribution might be further affected by increasing temperatures, which can expand the range of mosquitoes that spread dengue.",
      "source_date": "2026-05-15",
      "source_accessed": "2026-06-13",
      "calculation_notes": "Independent confirmation of the MMWR 85/105 split and the vector-range-expansion premise that motivates the entry. Used for the Aedes-range and warming framing in the prose.",
      "independence_note": "Independent academic center summarizing the MMWR; not a CDC publication."
    },
    {
      "url": "https://epi.ufl.edu/2025/06/24/dengue-in-florida-what-to-know/",
      "title": "Dengue in Florida: What to know",
      "publisher": "University of Florida Emerging Pathogens Institute",
      "source_type": "reputable_reference",
      "statistic": "Florida reported 1,044 local + travel-associated dengue cases in 2024 (most in the continental US); local cases concentrate in Miami-Dade County; no part of the US is officially endemic for dengue despite recurring local transmission.",
      "excerpt": "Although no part of the United States is officially labeled as endemic for dengue, Florida's health department continues to report cases acquired locally or linked to travel in 2025. [...] one case of locally acquired dengue in Miami-Dade County",
      "source_date": "2025-06-24",
      "source_accessed": "2026-06-13",
      "calculation_notes": "Grounds the Florida/Miami-Dade concentration in the regional_breakdown and the 'not endemic' caveat. The 1,044 figure is local+travel combined (most are travel-associated); only the locally-acquired subset (85) feeds the native rate."
    }
  ],
  "comparison_anchors": [
    {
      "label": "Plane crash death (lifetime, US)",
      "lifetime_us_adult": 0.000017
    },
    {
      "label": "Lightning strike (lifetime, US)",
      "lifetime_us_adult": 0.00000478
    },
    {
      "label": "Food poisoning death (lifetime, US)",
      "lifetime_us_adult": 0.000537
    }
  ],
  "regional_breakdown": [
    {
      "region": "Florida (esp. Miami-Dade)",
      "probability": 0.00022,
      "notes": "85 of the 105 continental locally-acquired cases in 2024 (81%) were in Florida, across 10 counties but concentrated in the Miami-Dade area. 85 / ~23M Florida residents = 3.7e-6/yr → ~2.2e-4 (~1 in 4,600) over 59 yr; the Miami-Dade sub-rate is higher still. Florida is not officially endemic but reports local cases every year."
    },
    {
      "region": "California (focal, Los Angeles County 2024)",
      "probability": 0.00002,
      "notes": "18 local cases statewide in 2024; LA County had 14 of them, all clustered within small radii consistent with focal outbreaks (some within a 1-mile radius over 7 weeks). 18 / ~39M = 4.6e-7/yr → ~2.7e-5 over 59 yr, but risk is concentrated in a few neighborhoods, not statewide."
    },
    {
      "region": "Most of the continental US (no established Aedes / no local cases)",
      "probability": 0.0000015,
      "notes": "Northern and interior states reported zero locally-acquired cases in 2024. Risk there is driven by occasional vector spread and remains near the lower bound."
    }
  ],
  "short_label": "Locally-acquired dengue (continental US)",
  "outcome_severity": "moderate_harm",
  "exposure_pattern": "acute",
  "outcome_type": "recoverable_injury",
  "valence": "negative",
  "caveats": "This is a snapshot of a volatile, geographically concentrated, and apparently expanding risk, not a stable lifetime constant. The point estimate rests on a single record year (2024, +359% above the 2010–2023 average), and projecting that rate across a 59-year horizon assumes 2024-era local transmission persists — a deliberate lean toward the upward Aedes-range and warming trend the entry describes. The uncertainty band spans two orders of magnitude (~1 in 670,000 to ~1 in 6,700) precisely because year-to-year local-case counts swing wildly and the true infection rate is undercounted: 40–80% of dengue infections are asymptomatic and many symptomatic cases go untested, so the headline 'diagnosed case' rate is a floor on actual exposure. The risk is overwhelmingly a Florida (esp. Miami-Dade) and focal-California phenomenon; for a resident of most of the continental US it sits near the lower bound. No published survey measures fear of catching dengue domestically, so the perception read is an intuition, not a poll. Because the band is wide and the denominator is national while the risk is local, D4 (uncertainty) and D5 (scope) are the weakest dimensions; both are handled explicitly via subgroup scope and a regional_breakdown rather than a single misleading national headline. The entry does not assert dengue is endemic anywhere in the continental US — no US jurisdiction is officially classified as endemic.",
  "quality_score": {
    "d1": 4,
    "d2": 5,
    "d3": 4,
    "d4": 3,
    "d5": 4,
    "d6": 4,
    "d7": 4,
    "d8": 4,
    "avg": 4,
    "scored_by": "claude-code-8d",
    "scored_at": "2026-06-13",
    "methodology_version": "8d-v1"
  },
  "reviewer": "8d-eval-2026-06-13",
  "last_reviewed": "2026-06-13",
  "reviewed": true,
  "generated_at": "2026-06-13",
  "image": {
    "alt": "An abstract editorial symbol evoking \"Locally-acquired dengue (continental US)\", muted two-tone palette, flat vector."
  },
  "attribution": "Likelier — https://likelier.app",
  "license": "https://creativecommons.org/licenses/by-sa/4.0/",
  "support": "https://buymeacoffee.com/kgluszczyk?via=likelier&utm_content=api-fear-single",
  "canonical_url": "https://likelier.app/us-local-dengue"
}