Are artefacts misleading the diagnosis of in microscopy? Observations.

Stool has multiple components, which include undigested food material, plant, animal products, normal intestinal microbiome, and parasites. Due to the existence of all the elements, stool parasite examination is cumbersome, especially with identification of the eggs of . We examined 650 stool samples of pregnant women before anti-helminthic treatment. We found that the prevalence of  was 5.4% (95% CI 3.8-7.4, n = 35) by a single observer in microscopy, and the majority (33/35) were identified as decorticated fertilized eggs. The prevalence of by molecular methods was 2.6% (95% CI 1.5-4.2%, n = 17). Five samples were positive by both methods. The prevalence of structures resembling  was 4.6% (95% CI 3.1-6.5, n = 30). Three of the positive samples were confirmed with sequencing. With the subjective nature of microscopy along with the naked eye examination, errors can happen. Hence adequate training and confirmation with molecular techniques for identification of are advisable.