a Countries are listed in decreasing order according to the before-after difference. The vertical line denotes the best estimate of prevalence and its range (depicted as a 95% uncertainty interval). These prevalence estimates were indirectly derived from estimates of incidence and the duration of disease previously published by WHO, adjusted to the year of the prevalence survey using previously published trends in incidence.
Estimates of TB prevalence (all ages, all forms of TB) for 12 surveys, before (in blue) and after (in red) results from national TB prevalence surveys implemented in Africa, 2008–2016a.