Infectious Disease · Medical Literature
[Articles] Accuracy of rapid diagnostic tests for Strongyloides stercoralis detection: a systematic review and meta-analysis
Abstract
Overall, RDT performance was in line with that indicated in the TPP. Hence, their further development for commercialisation for use in a public health context seems consonant. However, as part of this way forward, further research should support these results with properly designed studies, preferably prospective cohort studies with appropriate statistical methods that apply in the absence of a gold standard.
Clinical relevance
What is the diagnostic accuracy (sensitivity and specificity) of rapid diagnostic tests (RDTs) for the detection of Strongyloides stercoralis infection, and does their performance meet WHO target product profile (TPP) thresholds to support deployment in public health settings? __SNAPSHOT__ {"studyDesign":"Systematic review with meta-analysis of diagnostic test accuracy studies","setting":"Multi-country; conducted by investigators at IRCCS Sacro Cuore Don Calabria Hospital, Negrar di Valpolicella, Verona, Italy; included studies from endemic and non-endemic settings internationally","sampleSize":"18 studies included; aggregate patient-level sample size not reported in available abstract","population":"Individuals evaluated for Strongyloides stercoralis infection across diverse geographic and clinical settings, including migrants and community populations; immunocompromised individuals represented in only one included study","intervention":"Antibody-detecting rapid diagnostic tests (RDTs) — primarily lateral flow/immunochromatographic formats — for serodiagnosis of strongyloidiasis, evaluated since 2019; tests based on varying antibody–antigen combinations (including IgG and IgG4 against recombinant antigens such as NIE and SsIR)","comparator":"Performance benchmarked against the WHO Target Product Profile (TPP) minimum sensitivity threshold (≥50%) for diagnostics intended for strongyloidiasis public health control programs; reference standards included coproparasitological methods (Baermann, agar plate culture) and/or serology; no true gold standard exists","primaryOutcome":"Pooled sensitivity and specificity of RDTs for S. stercoralis detection, assessed against available reference standards and compared to WHO TPP thresholds","followUp":"Not applicable (cross-sectional diagnostic accuracy studies)","fundingSource":"Italian Ministry of Health (stated in article funding acknowledgment)"}
Key findings
Eighteen studies were included in the systematic review and meta-analysis. Excluding one study conducted exclusively in immunocompromised individuals, all evaluated RDTs achieved sensitivity at or above the WHO TPP minimum threshold of ≥50% for strongyloidiasis diagnostics intended for public health control programs. Specificity did not differ significantly across RDTs based on different antibody–antigen combinations. Heterogeneity across studies was substantial (I² 84.6–95.4%), precluding joint bivariate modelling of sensitivity and specificity; sensitivity and specificity were pooled separately as a pragmatic alternative. The single study enrolling immunocompromised patients yielded sensitivity below the TPP threshold, representing a clinically important exception. Pooled point estimates for sensitivity and specificity, confidence intervals, and NNT/NNH are not reported in the available abstract. Overall, the authors concluded that RDT performance was broadly in line with TPP-specified requirements. No adverse events are applicable to a diagnostic accuracy review. No specific numerical pooled estimates (e.g., overall sensitivity %, specificity %) were extractable from the abstract alone; values not reported here to avoid fabrication.
Practice implications
This systematic review and meta-analysis establishes that currently evaluated prototype RDTs for S. stercoralis serodiagnosis generally meet the WHO TPP minimum sensitivity threshold (≥50%) in immunocompetent populations, supporting the biological and technical plausibility of their future deployment for public health screening in endemic areas. However, several critical limitations substantially constrain the strength of this conclusion: (1) 16 of 18 included studies (88.9%) used a case-control design — a well-recognized source of spectrum bias that artificially inflates apparent sensitivity and specificity compared to prospective cohort designs reflecting real-world population prevalence; (2) heterogeneity was very high (I² up to 95.4%), limiting the reliability of any pooled estimate; (3) performance in immunocompromised patients — a population at highest risk for fatal hyperinfection syndrome — was evaluated in only one study and fell below TPP thresholds, meaning RDTs cannot yet be recommended for this group; (4) no true gold standard for S. stercoralis exists, complicating all accuracy assessments; and (5) no commercially available RDT exists at the time of publication. The findings do not establish readiness for clinical implementation but support continued investment in RDT development. Practice should not change on the basis of these data alone; prospective cohort studies using latent class or other gold-standard-free statistical methods are needed before RDTs can be recommended for routine use. NOTE: Only the abstract was available for this summary; exact pooled sensitivity/specificity estimates and confidence intervals could not be extracted and are not reported. __LIMITATIONS__ 16 of 18 included studies (88.9%) used a case-control design, introducing significant spectrum bias that likely overestimates diagnostic accuracy relative to real-world cohort performance,Substantial unexplained heterogeneity across all analyses (I² 84.6–95.4%), which undermines confidence in pooled estimates and limits meta-analytic precision,Absence of a true gold standard for S. stercoralis diagnosis; reference standards varied across studies and all carry imperfect sensitivity, biasing accuracy estimates in unpredictable directions,Immunocompromised patients — the highest-risk subgroup for fatal hyperinfection — were represented in only one study, with sensitivity falling below the TPP threshold in that group; results cannot be generalized to this population,RDT performance could not be stratified by age group due to insufficient data,No commercially available RDT was evaluated; all included tests are research-phase prototypes, limiting external validity,Not all sample and patient groups met eligibility criteria for inclusion, potentially introducing selection bias and reducing effective sample size in the meta-analysis,Study-level data only available (no individual patient data meta-analysis), restricting subgroup and interaction analyses,Only the abstract was available for this clinical summary; full numerical results, confidence intervals, and forest plot data could not be independently verified __BOTTOM_LINE_CATEGORY__ promising_but_preliminary __BOTTOM_LINE__ RDTs for Strongyloides stercoralis serodiagnosis appear to meet WHO TPP minimum sensitivity thresholds in immunocompetent populations, supporting their further development toward commercialization for public health screening in endemic settings. However, the evidence base is substantially weakened by near-universal case-control study designs, very high heterogeneity, the absence of a gold standard, and minimal data in immunocompromised individuals. No practice change is warranted at this time; well-designed prospective cohort studies using appropriate gold-standard-free statistical methods are required before RDTs can be recommended for clinical or programmatic implementation.