# An Agar-Free, Glass Bead-Based Method for the Culture of Strongyloides stercoralis: An Exploratory Diagnostic Sensitivity Study

## TL;DR

This study explores a new, eco-friendly method for diagnosing Strongyloides stercoralis infection using glass beads instead of agar, comparing its effectiveness to traditional methods.

## Contribution

The study introduces a recyclable glass bead-based culture method as a potential alternative to conventional agar plate culture for diagnosing strongyloidiasis.

## Key findings

- The APC and PCR after APC showed the highest sensitivity (84.62%) for detecting Strongyloides stercoralis.
- PCR on fresh stool had the lowest sensitivity (42.31%) compared to other methods.
- The bead-based culture (BPC) showed comparable sensitivity to APC, though not statistically significant.

## Abstract

Background/Objectives: The diagnosis of infection with Strogyloides stercoralis, recently targeted for control by the World Health Organization, (WHO), is challenging. Specific coproparasitological methods (agar plate culture [APC], Baermann sedimentation), recommended by the WHO for public health use, are labor-intensive and require bulky disposable materials as well as experienced microscopists. We explored the sensitivity of an alternative stool culture method using recyclable glass beads, followed by microscopy and PCR in comparison to routine APC and PCR performed on uncultured stool. Methods: We conducted a diagnostic sensitivity study on samples from patients with positive serology for strongyloidiasis who submitted stool specimens to our laboratory between January 2023 and December 2025 for parasitological confirmation. Samples were processed by routine APC and PCR on fresh stool, as well as experimental culture on bead-based plates (BPC), PCR on APC- and BPC-cultured stool, and PCR on stool incubated directly in the collection container. Results: Twenty-six of 110 samples (23.6%) tested positive in at least one technique. Within this subset, the most sensitive techniques were the APC and PCR after APC (both 84.62%); PCR on fresh stool was the least sensitive (42.31%) (p = 0.002). The sensitivity of BPC (65.38%) was lower than that of APC, although not statistically significantly. Comparable sensitivity was observed between microscopy and PCR after APC or BPC. PCR after incubation in the container showed a sensitivity of 57.69%. Agreement ranged from 50 to 84.6%. Conclusions: Alternative culture methods with more field-friendly implementation features could be interesting alternatives to standard methods. Further studies evaluating their performance and applicability in public health and clinical contexts are warranted.