|
Latent phase
| | |
|
Proportion of latent disease that is binned into latent fast
|
Range used in calibration
|
This parameter is calibrated [73,74,98-102]
|
|
Adults: 0.05-0.35
|
|
Children: set to 1/3 of adult value
|
|
Time to progress from latent fast to presymptomatic active disease
|
Exponentially distributed
|
[51,52]
|
|
Mean: 0.5 year
|
|
Time to progress from latent slow to active presymptomatic disease
|
Exponentially distributed
|
This parameter is calibrated [51,52,55,74,99]
|
|
Range: 5-10% of latent slow reactivate in their lifetime
|
|
Relative reduction in susceptibility to reinfection due to prior exposure to TB
|
0.65
|
[74,76,103]
|
|
Active phase
| | |
|
Time to progress from active presymptomatic to active symptomatic
|
Exponentially distributed
|
[53-59]
|
|
Mean: 1 year
|
|
Proportion of incident active symptomatic TB that is smear positive
|
Children: 0.15
|
[48,60,61]
|
|
Adult: 0.585
|
|
Proportion of incident active symptomatic TB that is smear negative
|
Children: 0.55
|
[48,60,61]
|
|
Adult: 0.315
|
|
Proportion of incident active symptomatic TB that is extrapulmonary
|
Children: 0.40
|
[60,104-107]
|
|
Adult: 0.1
|
|
Duration of active symptomatic disease (until disease resolution) if no treatment is available
|
Mean 5.5 years
|
[65]
|
|
Disease resolution in smear-positive patients, proportion self-cure
|
0.3
|
[65]
|
|
Disease resolution in smear-positive patients, proportion death
|
0.7
|
[65]
|
|
Disease resolution in smear-negative and extrapulmonary patients, proportion self-cure
|
0.8
|
[65]
|
|
Disease resolution in smear-negative and extrapulmonary patients, proportion mortality
|
0.2
|
[65]
|
|
Infectiousness
| | |
|
Infectiousness during latent phase
|
0
|
[50]
|
|
Infectiousness of active presymptomatic TB, relative to smear positive
|
0.1
|
[53-59]
|
|
Infectiousness of extrapulmonary TB, relative to smear positive
|
0
|
[108]
|
|
Infectiousness of smear-negative TB, relative to smear positive
|
0.15
|
[62-64]
|
|
Infectiousness during active symptomatic, smear-positive (contact rate) number of new infections per year
|
Range used in calibration: 1–7.5
|
This parameter is calibrated [47,82,103,109]
|
|
Relative fitness of MDR strain
|
1
|
[66-70]
|
|
Treatment seeking
| | |
|
Rate of seeking treatment
|
Exponentially distributed
|
[24-28,71]
|
|
Mean: 4 months
|
|
Rate of seeking retreatment (hospital)
|
Exponentially distributed
|
Assumption informed by expert opinion from Chinese CDC
|
|
Mean: 22 months
|
|
Rate of seeking retreatment (CDC)
|
Exponentially distributed
|
Assumption informed by expert opinion from Chinese CDC
|
|
Mean: 4 months
|
|
Relapsers - time from completion of treatment until relapse
|
Exponentially distributed
|
[76]
|
|
Mean: 9 months
|
