Comparison of FECPAKG2, a modified Mini-FLOTAC technique and combined sedimentation and flotation for the coproscopic examination of helminth eggs in horses

Abstract

Background Due to high prevalence of anthelmintic resistance in equine helminths, selective treatment is increasingly promoted and in some countries a positive infection diagnosis is mandatory before treatment. Selective treatment is typically recommended when the number of worm eggs per gram faeces (epg) exceeds a particular threshold. In the present study we compared the semi-quantitative sedimentation/flotation method with the quantitative methods Mini-FLOTAC and FECPAKG2 in terms of precision, sensitivity, inter-rater reliability and correlation of worm egg counts to improve the choice of optimal diagnostic tools. Methods Using sedimentation/flotation (counting raw egg numbers up to 200), we investigated 1067 horse faecal samples using a modified Mini-FLOTAC approach (multiplication factor of 5 to calculate epgs from raw egg counts) and FECPAKG2 (multiplication factor of 45). Results Five independent analyses of the same faecal sample with all three methods revealed that variance was highest for the sedimentation/flotation method while there were no significant differences between methods regarding the coefficient of variance. Sedimentation/flotation detected the highest number of samples positive for strongyle and Parascaris spp. eggs, followed by Mini-FLOTAC and FECPAKG2. Regarding Anoplocephalidae, no significant difference in frequency of positive samples was observed between Mini-FLOTAC and sedimentation/flotation. Cohen’s κ values comparing individual methods with the combined result of all three methods revealed almost perfect agreement (κ ≥ 0.94) for sedimentation/flotation and strong agreement for Mini-FLOTAC (κ ≥ 0.83) for strongyles and Parascaris spp. For FECPAKG2, moderate and weak agreements were found for the detection of strongyle (κ = 0.62) and Parascaris (κ = 0.51) eggs, respectively. Despite higher sensitivity, the Mini-FLOTAC mean epg was significantly lower than that with FECPAKG2 due to samples with > 200 raw egg counts by sedimentation/flotation, while in samples with lower egg shedding epgs were higher with Mini-FLOTAC than with FECPAKG2. Conclusions For the simple detection of parasite eggs, for example, to treat foals infected with Parascaris spp., sedimentation/flotation is sufficient and more sensitive than the other two quantitative investigared in this study. Mini-FLOTAC is predicted to deliver more precise results in faecal egg count reduction tests due to higher raw egg counts. Finally, to identify animals with a strongyle epg above a certain threshold for treatment, FECPAKG2 delivered results comparable to Mini-FLOTAC. Grpahical Abstract

Epidemiological study on factors influencing the occurrence of helminth eggs in horses in Germany based on sent-in diagnostic samples

“…For the combined sedimentation/flotation method, 15 g of faeces were resuspended in 40 ml of tap water as described previously (Boelow et al 2022 ). Briefly, the suspension was filtered through an 800-µm-mesh-size sieve and centrifuged at 400 × g for 10 min.…”

“…Data about the prevalence and intensity of strongyle and ascarid egg shedding in Germany are scarce, and risk factor analyses are often based on a limited number of samples (Nielsen et al 2014b , 2014a ; Raue et al 2017 ). Using a recently published dataset that was employed to compare different diagnostic methods for equine faecal samples (Boelow et al 2022 ) and for which questionnaire data regarding the distribution of potential risk factors were available, the present study aims to identify risk factors for the presence of strongyle and ascarid eggs in equine faecal samples but also for egg-shedding intensity. In this study, all samples were analysed in parallel using combined sedimentation/flotation, Mini-FLOTAC and FECPAK G2 .…”

“…In this study, all samples were analysed in parallel using combined sedimentation/flotation, Mini-FLOTAC and FECPAK G2 . Since sedimentation/flotation was found to be the most sensitive of these methods (Boelow et al 2022 ), data from this method were used to analyse data on the presence of parasites. Mini-FLOTAC was found to be the superior quantitative method in comparison to FECPAK G2 (Boelow et al 2022 ), and thus, for statistical analysis of faecal egg count (FEC) data, the Mini-FLOTAC results were chosen.…”

Ефективність Кількісних Методів Копроовоскопії За Наявності Еймеріозу У Кролів

“…Аналізуючи більшість існуючих методів досліджень фекалій на наявність інвазійних елементів (ооцист, яєць паразитів), можна відстежити їх спільні характеристики. Зокрема, це використання в методиках та способах флотаційних рідин, за допомогою яких відбувається спливання інвазійних елементів на поверхню розчинів [11][12][13][14].…”

Advantages and limitations of microscopy and molecular detections for diagnosis of soil-transmitted helminths: An overview

“…The advantages of molecular methods are they provide higher sensitivity and specificity than microscopy and are constantly improving due to new technologies in genomics and bioinformatics( Papaiakovou et al ., 2019 ).On the other hand, FECPAK G2 is a newly developed quantitative method for the microscopic quantification and detection of STH eggs in a human stool( Ayana et al ., 2018 ). FECPAK G2 involves a special microscope equipped with an electronic camera to capture the image of the sample ( Boelow et al ., 2022 ). The image is stored and shared through cloud storage to provide a reference for settings with the limited resource ( Moser et al ., 2018 ).…”