Prediction of the tuberculosis reinfection proportion from the local incidence.
BACKGROUND
Reinfection is a major contributor to tuberculosis (TB). It seems that the higher the local incidence, the higher the proportion of reinfection.


METHODS
Based on a systematic review of the literature, we established a regression model to predict the reinfection proportion from the local incidence. We then used our local data to verify the algorithm.


RESULTS
Of the 23 studies addressing reinfection in recurrent TB, 6 were population based. The reinfection proportion was correlated with the local incidence (reinfection proportion=-29.7+36.8 x log Incidence) (95% confidence interval [CI] for coefficient, 15.3-58.3; R2=0.849). The reinfection proportion in Taiwan (incidence, 62.4/100,000 people) was estimated to be 36% (95% CI, 3%-69%). Of our 49 recurrent patients, 51% had reinfection. Patients with reactivation seemed more likely to have underlying diseases and less likely to be smear positive. The relapse isolates seemed more resistant than the initial isolates.


CONCLUSIONS
The regression model could possibly predict the TB reinfection proportion from the local incidence. This algorithm is probably helpful in policy making for TB control programs. In areas where TB is endemic, reinfection might be responsible for >50% of TB cases, and aggressive surveillance to detect asymptomatic carriers could be an important strategy for controlling the disease.
Wang
Jann-Yuan
JY
Department of Internal Medicine, National Taiwan University College of Medicine, Taipei, Taiwan.
Lee
Li-Na
LN
Lai
Hsin-Chih
HC
Hsu
Hsiao-Leng
HL
Liaw
Yuang-Shuang
YS
Hsueh
Po-Ren
PR
Yang
Pan-Chyr
PC
D016172:DNA Fingerprinting; D005544:Forecasting; D006801:Humans; D015994:Incidence; D015233:Models, Statistical; D012008:Recurrence; D012044:Regression Analysis; D014376:Tuberculosis / Q000453:epidemiology* / Q000235:genetics / Q000635:transmission*