: Approximately 600 million people worldwide are infected with Strongyloides stercoralis. Many diagnostic laboratories use serology to detect the infection. SsRapid^® is a prototype IgG4 lateral flow test based on NIE recombinant protein. We compared SsRapid with two commercial IgG-ELISAs (Bordier and Euroimmun) using five sera groups (G1–5, N = 170). Healthy individuals from nonendemic areas (G1, N = 33) and Strongyloides larvae-positive patients (G2, N = 20) showed no significant difference (P > 0.05) among the three assays. The group of other parasitic infections (G3) showed that SsRapid results were more concordant with Bordier ELISA (73%, 35/48) than Euroimmun ELISA (65%, 31/48). In corticosteroid-treated cancer patients who were polymerase chain reaction–positive for Strongyloides (G4, N = 25), SsRapid showed a higher detection rate (28%, 7/25) than both ELISAs (4%, 1/25). Meanwhile, SsRapid showed significantly less infection prevalence among the endemic area population (G5) than the ELISAs. Overall, SsRapid showed good performance in detecting Strongyloides infection compared with the commercial IgG-ELISAs.

: A lateral flow rapid test for strongyloidiasis will greatly facilitate the control and elimination of the disease. Previously SsRapid prototype rapid test showed high diagnostic specificity to detect Strongyloides infection, determined using non-Strongyloides sera negative by IgG-ELISAs. Since high specificity is crucial before a test is used for public health control activities, further validation of its specificity is needed. Also, it needs to be ascertained whether non-Strongyloides sera positive by IgG-ELISAs and SsRapid are truly positive for Strongyloides or are cases of cross-reactivity. We performed 84 rapid tests (two types of dipsticks and cassettes) using 34 serum samples. They were divided into four groups based on Strongyloides infection and coinfection with other parasites and the availability of recombinant proteins and rapid tests for the latter. Sera was adsorbed using polystyrene microspheres beads separately coated with four recombinant parasite proteins. The small sample size is a limitation of this study; however, the overall results showed that the sera adsorption procedure was successful, and the SsRapid test is specific.

Accurate diagnosis of strongyloidiasis is crucial for effective treatment and prevention of complications. We reviewed the current landscape of diagnostic assays used in detecting Strongyloides infection in Southeast Asia. A literature search was performed using Scopus, PubMed, and Web of Science databases spanning the last three decades. Based on the exclusion and inclusion criteria, 52 papers were included in this review. We outlined the diagnostic methods used and their advantages and drawbacks. Insensitive parasitological methods were commonly used, thus underscoring the underestimation of Strongyloides infection rates in Southeast Asia. A combination of diagnostic methods (i.e., microscopy, molecular techniques, and serology) is preferred because it leads to more effective detection and higher prevalence rates. New approaches have been developed, including urine ELISAs and rapid lateral flow tests. Improving and standardizing diagnostics and making them more accessible can improve Strongyloides prevalence estimates and facilitate control efforts.

Toxocariasis is a widespread zoonotic parasitic disease with a significant socioeconomic impact, particularly on underprivileged communities. Limitations of existing diagnostic tools and vague presenting symptoms may lead to misdiagnosis, thus underestimating the actual global impact of the disease. The present study describes the isolation and production of novel recombinant monoclonal antibodies against Toxocara canis recombinant TES-26 antigen (rTES-26) utilizing a human helminth scFv phage display library. The isolated antibody clones were characterized based on their gene sequences and binding characteristics. Three clones representing unique gene families (clone 48: IgHV3-LV1; clone 49: IgHV3-LV3; clone 50: IgHV6-LV3) were isolated, but only clones 48 and 49 showed successful insertion of the full-length scFv antibody sequence after sub-cloning. Both clones produced antibody proteins of good solubility and satisfactory yield and purity. Binding assays via Western blot and ELISA using rTES-26 and Toxocara canis native protein showed that both monoclonal antibodies were highly specific and sensitive to the target antigen. A preliminary antigen detection ELISA showed the diagnostic potential of the monoclonal antibody proteins. The proteins can also be useful in studying host–parasite interactions and therapeutic applications.