Volume 28, Number 1—January 2022
Research
Transmission Dynamics of Large Coronavirus Disease Outbreak in Homeless Shelter, Chicago, Illinois, USA, 2020
Yi-Shin Chang, Stockton Mayer, Elizabeth S. Davis, Evelyn Figueroa, Paul Leo, Patricia W. Finn1
, and David L. Perkins1
, and David L. Perkins1
Table 3
Fitted model parameter values in study of transmission dynamics of coronavirus disease outbreak in homeless shelter, Chicago, Illinois, USA, 2020*
| Parameter | Fitted value | Description of parameter |
|---|---|---|
| β0 | 0.60 | Initial β |
| βf_pct_β0 | 0.11 | Final β as percentage of β0 |
| k | 2.0 | Rate of transformation of β |
| tTrans | 23 | Day where β reaches halfway between β0 and βf |
| σs | 0.098 | Rate of transition from E to Is compartment = 1/(incubation period) × (% symptomatic) |
| σa | 0.26 | Rate of transition from E to Ia compartment = 1/(incubation period) × (% asymptomatic) |
| Asymptomatic percentage | 0.73 | Asymptomatic percentage |
| ϒsp | 0.15 | Rate of transition from Is to Rs+ compartment = 1/(infectious period for symptomatic persons) |
| ϒap | 0.13 | Rate of transition from Ia to Ra+ compartment = 1/(infectious period for asymptomatic persons) |
| ϒsn | 0.046 | Rate of transition from Rs+ to R- compartment = 1/[(duration of RT-PCR–positivity) – (infectious period)] for symptomatic persons |
| ϒan | 0.12 | Rate of transition from Ra+ to R- compartment = 1/[(duration of RT-PCR–positivity) – (infectious period]) for asymptomatic persons |
| α | 0.32 | Rate of detection of I symptomatic persons through screening |
| λ0_pct_β | 1 | Rate of transmission between persons in Isolsoft and Susceptible compartment, as a percentage of β |
| λisol_pct_β | 1 | Rate of transmission between persons in isolation units and Susceptible compartment, as a percentage of β |
| ρ | 1/14 d* | Rate of return from isolation units to Recovered compartment = 1/[14 d]† |
| PCR sensitivity | 0.90 | RT-PCR sensitivity |
| ω0 | 0.75 | Rate of hospital admission of Infectious symptomatic persons before screening |
| ω | 0.39 | Rate of hospital admission of Isolsoft symptomatic persons during phase 2 |
*Details of optimization and calculation can be found in the Appendix. E, exposed; I, infectious; RT-PCR, reverse transcription PCR. †Value not fitted.
1These senior authors contributed equally to this article.
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