Table 2.
Factors associated with positive LTBI screening test results
| TST | QFT-GIT | HBHA-IGRA | ||||
|---|---|---|---|---|---|---|
| p | OR [CI 95%]) | p | OR [CI 95%] | p | OR [CI 95%] | |
| Mtb exposure | 0.0455 | 11.8 [0.6-232] | 0.4455 | 2.2 [0.5-10.3] | 0.0353 | 9.9 [1.1-90.7] |
| BCG | 0.2273 | 6.0 [0.2-136] | 1 | 0.7 [0.1-5.0] | 0.0318 | 15 [0.7-307] |
| CD4+ T-cell count | 0.8773 | NA | 0.7777 | NA | 0.6021 | NA |
| Viral load | 0.1844 | NA | 0.0261 | NA | 0.0752 | NA |
A non-random association between positive test results and 1) the presence of an Mtb exposure risk factor, 2) BCG vaccination status, 3) CD4+ T-cell counts and 4) viral loads was assessed for the TST, the QFT-GIT and the HBHA-IGRA. Fisher’s exact test and odds ratio (OR) with a 95% confidence interval (CI 95%) was applied for the dichotomous variables (presence or not of an Mtb exposure risk factor and BCG vaccination status). Chi-squared test for trend was used for CD4+ T-cell counts and viral loads organized into ordinal variables (CD4+ T-cell counts <50; 50–199; 200–499, >500 cell/mm3 and viral loads <40, 40–10000; 10000–100000; >100000 copies/ml). Significant p values are in bold type (p < 0.05).