Table 2.
Diagnostic performance of Mtb EV for TB among HIV-positive hospitalized ART-naïve children at high risk for TB (147 children*)
| Confirmed TBa | Unconfirmed TBa (66 children) | Unlikely TBa (69 children) | |||
|---|---|---|---|---|---|
| Microbiological confirmation (12 children) | Clinical TB diagnosisb (46 children) | No clinical TB diagnosisb (20 children) | Any NIH criteriac (57 children) | No NIH criteriac (12 children) | |
| Number of children positive according to Mtb EV | 10 | 35 | 13 | 31 | 2 |
| Sensitivity, % | 83.3 (51.6, 97.9) | 76.1 (61.2, 87.4) | 65.0 (40.8, 84.6) | 54.4 (40.7, 67.6) | – |
| Specificity, % | – | – | – | 45.6 (32.4, 59.3) | 83.3 (51.6, 97.9) |
| TB-untreated deaths, % and fraction | 100%, 2/2 | – | 50%, 10/20 | 17.9%, 10/56 | 0%, 0/12 |
| TB-treated deaths, % and fraction | 30.0%, 3/10 | 8.7%, 4/46 | – | 0%, 0/1 | – |
| Mtb EV levels, median | 24.6 (6.9, 66.5) | 16.6 (6.9, 31.6) | 8.5 (3.9, 18.6) | 7.1 (1.9, 23.8) | 2.7 (0.6, 4.6) |
| P valued | 0.001 | 0.0005 | 0.01 | 0.02 | Reference |
Confidence intervals (95%) for the sensitivities and specificities, and interquartile ranges for the Mtb EV levels are given in brackets.
*Includes 137 children with serum analysed at baseline; 7 at time of ‘unconfirmed TB diagnosis’ (6 at 2 weeks and 1 at 4 weeks post enrolment); and 3 ‘unlikely TB’ cases with missing baseline serum who had serum analysed at 2 weeks post enrolment.
aAssessed post-hoc on the basis of international consensus clinical-case definitions33: paediatric TB, children who were prospectively diagnosed during the study period by clinical staff and who received TBTx during the study period; no TB diagnosis or TBTx during study, children who were not clinically diagnosed and did not receive TBTx during the study period; NIH TB criteria, children who had at least one of the two diagnostic criteria required for TB diagnosis by the NIH algorithm.
bAssessed during the study. Clinical TB diagnosis: initiated TBTx. No clinical TB diagnosis: did not initiate TBTx.
cPositive CXR or TB exposure within the last two years; or TST ≥ 5 mm; or NIH TB symptoms: persistent cough (>14 d), fever (>7 d), failure to thrive, or lethargy (>7 d). Failure to thrive corresponds to wasted (WHZ < –2 or MUAC < 12.5) or underweight (WAZ < –2) at enrolment.
dWilcoxon rank-sum test (two-sided), compared to ‘unlikely TB with no TB symptoms’ and ‘negative CXR’.