# Syndromic Diagnostics for Travelers’ Diarrhea: Near-Patient Field-Expedient Testing in Resource-Limited Settings

## TL;DR

The study compares two diagnostic tests for travelers' diarrhea in resource-limited settings and finds that one is suitable for field use despite some limitations.

## Contribution

Demonstrates the suitability of the FilmArray PCR platform for field diagnostics in low-resource areas despite moderate concordance with a reference standard.

## Key findings

- FilmArray and Seegene PCR showed similar overall pathogen detection rates.
- FilmArray had low sensitivity for Campylobacter and norovirus.
- FilmArray is recommended for field use due to its versatility and ease of use.

## Abstract

We assessed the diagnostic agreement of BioFire FilmArray multiplex polymerase chain reaction (PCR) with Seegene Allplex PCR for testing fecal samples collected during a diarrhea outbreak in resource-limited settings.

Fecal samples from consented British military personnel training in Kenya were collected without preservative and tested onsite with the FilmArray PCR platform. Anonymized corresponding samples frozen near the point of care were tested 16–18 months later in the United Kingdom using Seegene PCR (reference standard). We compared test sensitivity and specificity and assessed agreement using Cohen κ coefficients.

Samples were analyzed from 60 individuals (80% male; median age [interquartile range], 24 [22–28] years). The overall pathogen detection rates did not differ significantly between FilmArray and Seegene PCR (55 of 60 [91.7%] vs 53 of 59 [89.8%], respectively [P > .9]). Campylobacter spp detection was significantly higher with Seegene (17 of 59 [28.8%] vs 6 of 60 [10%] for FilmArray PCR P = .03). The sensitivity of FilmArray PCR was moderate for Cryptosporidium spp (65% [95% confidence interval, 45.37%–80.77%]), and low for Campylobacter spp (35.3% [14.21%–61.67%%) and norovirus (7.14% [.18%–33.87%]). Its specificity was good to excellent for detection of Campylobacter spp, Cryptosporidium spp, enteroaggregative Escherichia coli, and sapovirus.

The study shows moderate concordance of FilmArray with Seegene PCR in the detection of 5 enteropathogens and poor to fair concordance for 7 others, but high-quality case-control studies are needed to assess agreement between these platforms. However, based on performance characteristics, including platform versatility and ease of use, and in the absence of a gold (reference) standard test, the FilmArray platform remains a suitable near-patient field-expedient platform for diarrhea diagnostics in resource-limited settings.