Improvement in the detection of enteric protozoa from clinical stool samples using the automated urine sediment analyzer sediMAX® 2 compared to sediMAX® 1

Detection of intestinal parasites from fecal samples is routinely performed by direct wet mount examination. This method requires skilled personnel, and it is time consuming. The aim of this work is to demonstrate the usefulness of the newer automated urinary sediment analyser sediMAX 2 for a fast detection of intestinal protozoa in stool samples. A total of 700 consecutively preserved samples consisting of 70 positives and 630 negatives were analyzed. SediMAX 2 takes digital images of each sediment sample, and analysis was conducted using a dilution of stool specimens, allowing determination of typical morphology. Compared to manual microscopy, sediMAX 2 showed sensitivity and specificity of 100 % in the detection of intestinal parasites, as also recently demonstrated for sediMAX 1. However, all clinically important human protozoa were detected using only 15 images for each specimen, compared to 30 images required in sediMAX 1 analysis. Moreover, changing manually the focus, it is possible to carry out a discrimination between morphologically identical Entamoeba complex members, including the pathogenic E. histolytica and the non-pathogenic E. dispar, E. moshkovskii and E. Bangladeshi, from the non-pathogenic Entamoeba coli based on the number of nuclei present in the cells. This study presents sediMAX 2 as an automatic aid to traditional microscopy.