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

Abstract Background 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. Methods 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. Results 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. Conclusions 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.