Table 1.
Estimated parameters by city
| Parameter | Definition | Value* | Source |
| ξ | Probability of a rat acquiring plague from bite of infected flea | 0–1 | Scaling factor |
| 1/σ | Mean incubation period in rats | 3 d | Ref. 60 |
| 1/μ | Mean time to plague-induced mortality | 2.6 d | Ref. 60 |
| b | Maximal rat birth rate (per rat, per day, log10) | −1.532 to –1.325 | |
| 1/d | Mean rat lifespan without plague infection | 180 d | Refs. 55 and 61 |
| K | Rat population carrying capacity | 1 | Scaling factor |
| ι | Fecundity reduction for a fully resistant rat (reference fully susceptible) | 23.3–23.6% | Estimated |
| ε | SD of offspring susceptibility (reference parent susceptibility) | 0.001–0.1 | Varied |
| ϕ | Flea shedding rate from rats | 1 | Scaling factor |
| 1/ψ | Mean survival of foraging fleas under observed temperatures | 1.9–2.8 d | Estimated |
| α | Mean to peak amplitude of seasonal variation in flea mortality | 9.1–17.5% | Estimated |
| ω | Calendar day of longest flea lifespan | Varies by city | Estimated |
| 1/ν | Mean duration of incubation and illness in humans | 10 d | Ref. 62 |
| h | Flea searching efficiency (log10) | −7.34 to –9.70 | Estimated |
| β | Flea–rat contact rate | 0.233–0.288 | Estimated |
*
Presented values from estimated parameters describe the range inferred across all three cities, from the lowest 2.5 percentile to the highest 97.5 percentile of prediction intervals, for the model with host evolution. Posterior distributions are presented in Table S1, and estimates for the model without evolution are in Table S2.