Volume 24, Number 10—October 2018
Simple Estimates for Local Prevalence of Latent Tuberculosis Infection, United States, 2011–2015
|Jurisdiction||Population||Average annual no. active TB cases||Proportion of TB cases attributed to recent transmission||Annual no. cases attributed to reactivation TB||Estimated no. infected residents if 0.10% annual risk for progression||Estimated prevalence of infection if 0.10% annual risk for progression, %||Sensitivity analysis for estimated prevalence of latent infection, %|
|Lower uncertainty limit based on 0.14% annual risk for progression||Upper uncertainty limit based on 0.06% annual risk for progression|
|Example X||Any size||0||NA||0||NA||<1||NA||NA|
*Let a = jurisdiction population, b = average annual no. TB cases in that jurisdiction, and c = proportion of TB cases attributed to recent transmission (i.e., [1 – c] = proportion attributed to latent TB infection). Then if b = 0, d = 0, and f <1%, otherwise d = b × (1 – c) and e = d/0.0010 if one assumes a 0.10% annual risk and f = e/a (×100 to express as a percentage) or (d/0.0014/a for lower uncertainty limit and h = d/0.0006/a for upper uncertainty limit. NA, not applicable; TB, tuberculosis.