TABLE 1.

PARAMETERS FOR TRANSMISSION MODEL OF TB

Parameter	Baseline Value (Uncertainty Range)	References
TB incidence, per 100,000 per year*	112 (101–128)	4
Endogenous reactivation rate, per year	0.0005 (0.0001–0.001)	2, 21, 22
Proportion of recent infections resulting in rapid progression	0.14 (0.08–0.25)	2, 23
Reduction in TB rapid progression probability in people with latent TB infection†	0.5 (0.1–0.8)	2, 23–25
TB mortality rate, per year	0.2 (0.15–0.3)	2, 4
Spontaneous cure rate, per year	0.2 (0.15–0.25)	2, 19, 20
Life expectancy, yr	65 (55–75)	26
Relapse rate, per year	0.001 (0–0.002)	2, 27
Total duration of TB infectiousness, yr	1.5 (1.0–2.0)	4

Definition of abbreviation: TB = tuberculosis.

^*The model fits a transmission rate to TB incidence, first by determining the transmission rate that would produce an equilibrium incidence of 128 per 100,000 per year, then reducing that rate by a value sufficient to generate a 1.3% annual decline in TB incidence (i.e., 112 per 100,000 after 10 years), the global estimate (4). The baseline value of this transmission parameter is five infections per infectious person-year.

^†This parameter reflects the partial immunologic protection provided by initial TB infection (i.e., latent infection) against primary progression to active TB on reexposure to Mycobacterium tuberculosis.