Characteristics of household contacts (HHCs) of pulmonary tuberculosis cases and individuals from their source population (SP).

<p>*Only index cases that lead to household contacts included.</p><p>†p value (two tailed) refers to comparison of characteristics in HHCs and individuals from SP.</p><p>‡SES categories as defined in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0008257#s2" target="_blank">Methods</a>.</p

Correlation between TST and IFNγ production in response to CFP and CFP-10 by age in household contacts (HHCs) and individuals from source population (SP).

<p>*Spearman correlation coefficient <i>r</i>. All p values<0.001.</p><p>†TST (mm of induration); IFNγ (pg/mL).</p

Hazard of TB development according to IFNγ production.

<p>Hazard levels of tuberculosis development taking the modified version of IFNγ production categories proposed by Andersen et al <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0008257#pone.0008257-Andersen1" target="_blank">[11]</a> as baseline predictors of disease. Negative: <22pg/mL, Low: 22–99 pg/mL Medium: 100–999 pg/mL, High: ≥1000 pg/mL. HHCs: Household Contacts SP: Source Population.</p

Incidence of active tuberculosis in household contacts and IFNγ production levels at baseline.

<p>*Negative: <22pg/mL, Low: 22–99 pg/mL Medium: 100–999 pg/mL, High: ≥1000 pg/mL.</p><p>†Total positive: (Negative + Low + Medium + High).</p

Comparison of baseline IFNγ production by TB incident and non–incident HHCs in response to the antigens used.

<p>*Student t - test.</p><p>†Chi-square (χ²) test.</p

IFNγ production levels by age.

<p>Geometric means of IFNγ production in response to CFP (A) and CFP-10 (B) by age in household contacts (HHCs) and individuals from source population (SP). Horizontal lines depict the cut-off value (22 pg/mL).</p

Incidence of active tuberculosis in household contacts according to age.

<p>Incidence of active tuberculosis in household contacts according to age.</p

Study profile.

<p>HHCs = Household contacts, IGRA = IFNγ Release Assay, TST = Tuberculin Skin Test, SP = source population, CFP-10 = Culture Filtrate Protein-10.</p