8 days
CDC describes acute symptoms typically resolving within 7-10 days. Eight days is a rounded representative choice inside that interval, not the observed mean for this outbreak. Persistent joint symptoms are excluded. [S4]
Disease outbreak
Experimental estimate · v0.2Paraguay chikungunya outbreak
Estimated USU1.3 million
Acute chikungunya symptoms
Reported deaths52
Probable / confirmed subset. Source context
Population modeled81,037
reported cases
Approximate, assumption-based USU for the included experience. Deaths are a separate measure.
Reading the result
What this estimate tells us
The model assigns about 16.3 USU per reported case using eight days at intensity 4. Persistent joint pain is outside this estimate, so the report measures the acute course only.
The calculation
The inputs behind the estimate
81,037 × 8 days × 24 hours × 4 ÷ 47.25
≈ 1.3 million USU
≈ 1.3 million USU
16.3 USU per modeled course, before multiplying by the reported count. The calculation uses unrounded values; only the headline is rounded.
Intensity is assigned on a 0–10 scale and averaged over the whole elapsed course, including relief and sleep. Why divide by 47.25?
4 / 10
CDC describes potentially severe, debilitating joint symptoms; Paraguay's adult suspected-case definition included incapacitating joint pain or arthritis. These support testing a higher average than dengue. Assigned intensity 4, and the 4:3 ratio, remain model judgments rather than measured equivalence. [S3] [S4]
How much can the assumptions change the result?
At 7 days and intensity 3, the result is about 0.86 million USU. At 10 days and intensity 5, it is about 2.1 million USU.
These are alternative input scenarios, not confidence intervals or bounds on all uncertainty. Some cross-condition orderings change under these choices. The headline uses the single shared template above.
Coverage
What goes into this number?
Included
A single acute symptom course for each suspected, probable or confirmed case, with incapacitating joint symptoms represented within one combined intensity.
Source population and period
Torales et al., CDC MMWR, 9 June 2023: 81,037 suspected, probable or confirmed cases during 1 October 2022-11 March 2023. Discarded negative-tested cases are excluded by the source. This is an interim outbreak count, not the final 2023 total. [S3]
Outside this estimate
Persistent/recurrent joint pain, rare complications as separate profiles, caregiver distress, unreported infections and post-death loss.
Omitted experiences are unestimated, not known to be zero. This is not a complete event total or a guaranteed lower bound.
Whole representative courses are assigned to the source-defined cases or cohort. Course time can extend beyond the reporting dates. Individual trajectories, fatal-case truncation and a causal baseline are not reconstructed; no suffering after death is assigned.
Deaths remain separate
Mortality source context
52 attributable deaths among 47,116 probable/confirmed cases, a narrower subset than the modeled case count; separate from USU. [S3]
USU estimates experienced suffering during lived time. The death count is shown alongside it and is not converted into USU.
Trace the estimate
Sources and calculation data
- [S3] Torales M et al. Chikungunya Outbreak - Paraguay, 2022-2023. CDC MMWR 2023;72:636-638. 9 June 2023.
81,037 reported cases, reporting dates and case definitions; mortality subset distinction.
- [S4] CDC. Clinical Signs and Symptoms of Chikungunya Virus Disease. 15 May 2024.
Severe/debilitating joint symptoms and typical 7-10-day acute course; no USU conversion.
- [S8] WSI event list v0.2: USU reference convention (unchanged from v0.1).
Stipulated six-hour kidney-stone reference: 47.25 modeled intensity-hours, with linear weighting. This convention defines the unit; it is not a measured equivalence between conditions.