Multicenter Evaluation of BD Max Enteric Parasite Real-Time PCR Assay for Detection of Giardia duodenalis, Cryptosporidium hominis, Cryptosporidium parvum, and Entamoeba histolytica

Abstract

Common causes of chronic diarrhea among travelers worldwide include protozoan parasites. The majority of parasitic infections are caused by Giardia duodenalis, Entamoeba histolytica, Cryptosporidium parvum, and Cryptosporidium hominis. Similarly, these species cause the majority of parasitic diarrhea acquired in the United States. Detection of parasites by gold standard microscopic methods is time-consuming and requires considerable expertise; enzyme immunoassays and direct fluorescent-antibody (DFA) stains have lowered hands-on time for testing, but improvements in sensitivity and technical time may be possible with a PCR assay. We performed a clinical evaluation of a multiplex PCR panel, the enteric parasite panel (EPP), for the detection of these common parasites using the BD Max instrument, which performs automated extraction and amplification. A total of 2,495 compliant specimens were enrolled, including 2,104 (84%) specimens collected prospectively and 391 (16%) specimens collected retrospectively. Approximately equal numbers were received in 10% formalin (1,273 specimens) and unpreserved (1,222 specimens). The results from the EPP were compared to those from alternate PCR and bidirectional sequencing (APCR), as well as DFA (G. duodenalis and C. parvum or C. hominis) or trichrome stain (E. histolytica). The sensitivity and specificity for prospective and retrospective specimens combined were 98.2% and 99.5% for G. duodenalis, 95.5% and 99.6 for C. parvum or C. hominis, and 100% and 100% for E. histolytica, respectively. The performance of the FDA-approved BD Max EPP compared well to the reference methods and may be an appropriate substitute for microscopic examination or immunoassays.

The Little Beast That Pretended to Be a Severe Crohn's Disease

“…In our case, serology ultimately confirmed the diagnosis, although polymerase chain reaction usually has a higher sensitivity and specificity for this diagnosis. 1 The most surprising part was our patient's clinical and biological response to corticosteroid therapy, which could have resulted in aggravation of the symptomatology. Indeed, a review of the recent literature revealed a 58% rate of fulminant colonic amoebiasis, which is the rarest but also the most serious complication (25% of the deaths), in patients who were treated with corticosteroids for undetermined colitis.…”

Comparison of multiplexed-tandem real-time PCR panel with reference real-time PCR molecular diagnostic assays for detection of Giardia intestinalis and Tritrichomonas foetus in cats

“…Our study demonstrates that the assay is equally specific for the feline G. intestinalis Assemblage F, because all feline samples in this study that were genotyped were confirmed as G. intestinalis Assemblage F -the genetically defined subgroup specific for cats (Feng and Xiao, 2011). In clinical diagnostics the G. intestinalis assemblage is not determined for cat, dog or human samples (Gizzi et al, 2014;Madison-Antenucci et al, 2016;Stark et al, 2014;Verweij et al, 2004). Most research studies have demonstrated G. intestinalis Assemblage F being shed by cats; only in exceptional circumstances were the zoonotic G. intestinalis Assemblages A and B detected (Feng and Xiao, 2011;Gruffydd-Jones et al, 2013).…”

New Developments in Rapid Diagnostic Testing for Children

“…Studies on each of these assays has been published, and all assays show high sensitivity and specificity for their respective targets. [24][25][26][27][28][29][30][31] In fact, these multiplex panels result in increased and unexpected detections that would not be identified by the ordering preference of the clinician. For example, in a study by Stockmann and colleagues, 32 they noted that for patients with only Clostridium difficile testing, the FilmArray Gastrointestinal pathogen panel identified an alternative pathogen in 29% of those patients.…”