Molecular detection of common intestinal parasites: a performance evaluation of the BD Max™ Enteric Parasite Panel

The purpose of this study was to evaluate the level of agreement of the BD Max™ Enteric Parasite Panel (EPP) with microscopy for the detection of Giardia duodenalis, Cryptosporidium spp. and Entamoeba histolytica in stool samples. A total of 372 stool samples (partly collected on the basis of positive microscopy and partly unselected, consecutive sample submitted for parasite investigation) were tested with EPP according to manufacturer's instructions and also using microscopy according to standard techniques. Discrepant samples were further tested using PCR by the National Parasitology reference laboratory. Levels of agreement and laboratory turnaround times were measured and compared. Overall, positive and negative percent agreement was high between the two methods. However, microscopy resulted in four false positives and one false negative for G. duodenalis and two false positives for Cryptosporidium. Additionally, microscopy could not differentiate between E. histolytica and Entamoeba dispar. Median laboratory turnaround time was 65 hours for microscopy; results from EPP could be available after four hours. Blastocycstis hominis was detected by microscopy in one sample and would have been missed if only EPP was performed. The EPP was a good alternative to microscopy, detecting a small number of additional positives that were missed by microscopy. The assay is significantly faster than microscopy and allows laboratory workflows to be streamlined. The risk of missing parasites that are not included in the EPP appears to be minimal in the studied population; however, there may be certain patient groups who would benefit from microscopic examination of stools.