Table 2.
Studies of lateral flow rapid tests for the detection of Strongyloides stercoralis infection
| No. | Format | Antigen | Detecting antibody (gold-conjugated) | Sample dilution | Diagnostic sensitivity | Diagnostic specificity | Positive and negative predictive values | Intensity reading chart | Location | Reference |
|---|---|---|---|---|---|---|---|---|---|---|
| 1a | Cassette | Recombinant protein (SsIR) | IgG | 1:100 | 91.7% (55/60) | 83.8% (88/105) | 76.4%, 94.6% | Nine line intensity levels, 8–0.5; cutoff intensity level ≥ 1 | Thailand | Boonroumkaew et al. (2020) |
| 1b | Cassette | Recombinant protein (SsIR) | IgG4 | 1:100 | 78.3% (47/60) | 84.8% (89/105) | 76.4%, 87.3% | Nine line intensity levels, 8–0.5; cutoff intensity level ≥ 0.5 | Thailand | Boonroumkaew et al. (2020) |
| 2 | Cassette | Larvae extract of Strongyloides stercoralis | IgG | 1:50 | 93.3% (56/60) | 83.7% (87/104) | 76.7%, 95.6% | Nine line intensity levels, 8–0.5; cutoff intensity level ≥ 0.5 | Thailand | Sadaow et al. (2020) |
| 3 | Dipstick | Recombinant proteins (rNIE and rSs1a) | IgG4 | 1:2 | 91.3% (21/23) | 100% (82/82) | 100%, 7.6% | Intensity of the test line was quantified using image analysis software | Malaysia | Yunus et al. (2019) |
| 4 | Dipstick | Recombinant proteins (rNIE and rSs1a) | IgG4 | 1:2 | 82% (69/84) | 96% (24/25) | 98.6%, 61.5% | Four intensity scores for positive results: +1 to +4; negative result: no test line | Thailand | Present study |
SsIR = S. stercoralis immunoreactive recombinant antigen. All evaluation studies except study 4 were performed at the location where the tests were developed.