Flow diagram of enrollment.

<p>TB: tuberculosis, QFT: QuantiFERON-TB Gold In-Tube, TST: Tuberculin Skin Test.</p

Probability of non LTBI (LTBI^c) in children up to 6 years of age according to the results of both tests in the latent class model (first phase).

<p>Probability of non LTBI (LTBI^c) in children up to 6 years of age according to the results of both tests in the latent class model (first phase).</p

Results of the prevalence of LTBI according to exposure to an index TB case and the sensitivity and the specificity of QFT and TST in children up to 6 years of age in Manaus, Brazil (first phase).

<p>Results of the prevalence of LTBI according to exposure to an index TB case and the sensitivity and the specificity of QFT and TST in children up to 6 years of age in Manaus, Brazil (first phase).</p

Prevalence of LTBI according to the time of exposure of 0, 1, 3, 6 and 12 months and the MTC-score values of 4, 8, 13 and 15 in children up to 6 years of age in Manaus, Brazil.

<p>MTC-SCORE: <i>Mycobacterium tuberculosis</i> contact score.</p

Estimation of the sensitivity and specificity of QFT and TST, and the coefficients of regression of the variables of time of exposure and MTC-Score associated with the prevalence (second phase).

<p>Estimation of the sensitivity and specificity of QFT and TST, and the coefficients of regression of the variables of time of exposure and MTC-Score associated with the prevalence (second phase).</p

Probability of LTBI in children up to 6 years of age according to the results of both tests in the latent class model (first phase).

<p>Probability of LTBI in children up to 6 years of age according to the results of both tests in the latent class model (first phase).</p

Multivariate logistic regression according to factors for positive QFT results stratified by TST results.

<p>TST: Tuberculin Skin Test, QFT: QuantiFERON-TB Gold In-Tube, MTC-score: <i>Mycobacterium tuberculosis</i> contact score, BCG: Bacillus Calmette-Guérin.</p>a<p>logistic regression coefficient related to quantitative variable.</p>b<p>Linear odds ratio; exponential to the regression coefficient.</p

Odds ratio and confidence interval of 95% for the Tuberculin Skin Test –TST− (blue) and QuantiFERON-TB Gold in-Tube –QFT− (red) positive results according to the intensity of exposure to index case by <i>Mycobacterium tuberculosis</i> contact score (MTC-score).

<p>The MTC-score is from 0 to 15 and is based on the assumption that the gradient of <i>Mtb</i> exposure is a composite function of the infectivity of the index case (0–4), the duration of exposure -hours per day- (0–4), the relationship to index case (0–4) and the type of exposure (0–3).</p

Odds ratio and confidence interal of 95% for the Tuberculosis Skin Test positive results according to time of exposure (months) to index case.

<p>Odds ratio and confidence interal of 95% for the Tuberculosis Skin Test positive results according to time of exposure (months) to index case.</p

Baseline demographic and clinical data of the study participants.

<p>TST: Tuberculin Skin Test, QFT: QuantiFERON-TB Gold In-Tube, MTC-score: <i>Mycobacterium tuberculosis</i> contact score, BCG: Bacillus Calmette-Guérin.</p>#<p>Categorical variables expressed as number of subjects (n) and percentage (%) compared to those evaluated with the characteristic studied. Quantitative variables expressed as mean and interquartile range (IQR).</p>a<p>In the 12 weeks prior to the study.</p>b<p>Risk of malnutrition was defined as a Z score for weight less than −1 SDs for age and gender; malnutrition was defined −2 SDs for age and gender.</p