Sensitivity of the tests.

<p>Points represent the estimates and lines the 95% CIs. Active and passive refer to active and passive screening.</p

Flow diagram of participant enrolment.

<p>Note that for illustrative purposes in this flow diagram, if either reader recorded a positive result then it is recorded as positive in this Figure.</p

Combinations of positive screening tests.

<p>Combinations of positive screening tests.</p

Performance of the SD BIOLINE® HAT rapid test in various diagnostic algorithms for <i>gambiense</i> human African trypanosomiasis in the Democratic Republic of the Congo

<div><p>We carried out a study to compare the performance, in terms of sensitivity and specificity, of the new SD BIOLINE^® HAT rapid diagnostic test (RDT) with the card agglutination test for trypanosomiasis (CATT) for diagnosis of human African trypanosomiasis (HAT) in the Democratic Republic of the Congo (DRC). Participants were enrolled actively by four mobile teams, and passively at four health facilities in three provinces. Consenting participants were tested concurrently with the RDT and CATT on whole blood. Those found positive by either test were tested with CATT on serial dilutions of plasma, and with a parasitological composite reference standard (CRS). Cases were only the individuals found positive by the CRS, while controls were negative by both CATT and RDT, as well as those that were positive by CATT or RDT, but were negative by the CRS, and had no history of HAT. Over five months, 131 cases and 13,527 controls were enrolled. The sensitivity of the RDT was 92.0% (95% confidence interval (CI) = 86.1–95.5), which was significantly higher than CATT (sensitivity 69.1%; 95% CI = 60.7–76.4). The sensitivity of CATT on plasma at a dilution of 1:8 was 59.0% (95% CI = 50.2–67.2). The specificity of the RDT was 97.1% (95% CIs = 96.8–97.4) while that of CATT was 98.0% (95% CIs = 97.8, 98.2) and specificities of algorithms involving CATT at 1:8 dilution were 99.6% (95% CI = 99.5–99.7). Reproducibility of results was excellent. We concluded that an algorithm in which the SD BIOLINE^® HAT RDT is used for screening is optimal for case detection in both passive and active screening settings. However, the lower specificity of the RDT compared to that of CATT would result in a larger number of false positive individuals undergoing confirmatory testing.</p></div

Flow diagram of the diagnostic algorithm.

<p>Flow diagram of the diagnostic algorithm.</p

Screening test specificity.

<p>Screening test specificity.</p

Sensitivity and specificity of devices by each reader (R1 and R2) and by duplicate device (D1 and D2).

<p>Error bars are 95% confidence intervals of a proportion.</p

Screening test sensitivity.

<p>Screening test sensitivity.</p

Specificity of the tests.

<p>Points represent the estimates and lines the 95% CIs. Note the y-axis range is 90–100%. Active and passive refer to active and passive screening.</p

Venn diagrams showing the number of false positive results obtained with the RDT2, RDT1 and CATT tests.

<p>(A) Results from active and passive screening combined (N = 1,768 false positives); (B) results from active screening (N = 769 false positives); (C) results from passive screening (N = 999 false positives). For the sake of simplicity, only results obtained by the first reader are shown.</p