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Ally O, Kanoi BN, Ochola L, Nyanjom SG, Shiluli C, Misinzo G, Gitaka J. Schistosomiasis diagnosis: Challenges and opportunities for elimination. PLoS Negl Trop Dis 2024; 18:e0012282. [PMID: 38990839 PMCID: PMC11239039 DOI: 10.1371/journal.pntd.0012282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2024] Open
Abstract
OVERVIEW The roadmap adopted by the World Health Organization (WHO) for eliminating neglected tropical diseases aims to eliminate schistosomiasis, as a public health concern, by 2030. While progress has been made towards reducing schistosomiasis morbidity control in several sub-Saharan African countries, there is still more that needs to be done. Proper surveillance using accurate diagnostics with acceptable sensitivity and specificity is essential for evaluating the success of all efforts against schistosomiasis. Microscopy, despite its low sensitivity, remains the gold standard approach for diagnosing the disease. Although many efforts have been made to develop new diagnostics based on circulating parasite proteins, genetic markers, schistosome egg morphology, and their paramagnetic properties, none has been robust enough to replace microscopy. This review highlights common diagnostic approaches for detecting schistosomiasis in field and clinical settings, major challenges, and provides new and novel opportunities and diagnosis pathways that will be critical in supporting elimination of schistosomiasis. METHODS We searched for relevant and reliable published literature from PubMed, Scopus, google scholar, and Web of science. The search strategies were primarily determined by subtopic, and hence the following words were used (schistosom*, diagnosis, Kato-Katz, antibody test, circulating antigen, POC-CCA, UCP-LF-CAA, molecular diagnostics, nucleic acid amplification test, microfluidics, lab-on a disk, lab-on chip, recombinase polymerase amplification (RPA), LAMP, portable sequencer, nanobody test, identical multi-repeat sequences, diagnostic TPPs, REASSURED, extraction free), and Boolean operators AND and/OR were used to refine the searching capacity. Due to the global public health nature of schistosomiasis, we also searched for reliable documents, reports, and research papers published by international health organizations, World Health Organization (WHO), and Center for Disease control and Elimination.
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Affiliation(s)
- Ombeni Ally
- Department of Molecular Biology and Biotechnology, Pan African University Institute for Basic Sciences, Technology and Innovation (PAUSTI), Nairobi, Kenya
- Department of Biology, College of Natural and Mathematical Sciences, University of Dodoma, Dodoma, Tanzania
| | - Bernard N Kanoi
- Centre for Research in Infectious Diseases, College of Graduate Studies and Research, Mount Kenya University, General Kago Rd, Thika, Kenya
| | - Lucy Ochola
- Department of Tropical and Infectious Diseases, Institute of Primate Research, Nairobi, Kenya
| | - Steven Ger Nyanjom
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Clement Shiluli
- Centre for Research in Infectious Diseases, College of Graduate Studies and Research, Mount Kenya University, General Kago Rd, Thika, Kenya
| | - Gerald Misinzo
- SACIDS Africa Center of Excellence for Infectious Diseases, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Jesse Gitaka
- Centre for Research in Infectious Diseases, College of Graduate Studies and Research, Mount Kenya University, General Kago Rd, Thika, Kenya
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Rubagumya SL, Nzalawahe J, Misinzo G, Mazigo HD, Briet M, Misko VR, De Malsche W, Legein F, Justine NC, Basinda N, Mafie E. Evaluation of Lab-on-a-Disc Technique Performance for Soil-Transmitted Helminth Diagnosis in Animals in Tanzania. Vet Sci 2024; 11:174. [PMID: 38668441 PMCID: PMC11054913 DOI: 10.3390/vetsci11040174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 03/30/2024] [Accepted: 04/11/2024] [Indexed: 04/29/2024] Open
Abstract
Soil-transmitted helminth (STH) infections are caused by roundworms, hookworms, whipworms, and thread worms. Accurate diagnosis is essential for effective treatment, prevention, and control of these infections. This study evaluates a new diagnostic method called Single-image Parasite Quantification (SIMPAQ), which uses a lab-on-a-disc (LoD) technique to isolate STH eggs into a single imaging zone for digital analysis. The study evaluates the purification performance of the SIMPAQ technique for detecting STH eggs in animal samples. This was a cross-sectional study conducted among 237 pigs and 281 dogs in the Morogoro region in Tanzania. Faecal samples were collected and processed with the LoD technique, as well as flotation and McMaster (McM) methods for comparison purposes. The overall prevalence of STH infections was high as per the LoD technique (74%), followed by McM (65.44%) and flotation (65.04%). Moreover, the overall performance of the LoD technique, using McM as the gold standard, was 93.51% (sensitivity), 60.89% (specificity), 81.91% (PPV), and 83.21% (NPV). The LoD technique exhibited high prevalence, sensitivity, and NPV, which demonstrates its value for STH egg detection and its crucial role in the era of accurate STH diagnosis, promoting proper management of the infection.
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Affiliation(s)
- Sarah L. Rubagumya
- Department of Microbiology, Immunology and Parasitology, College of Health and Allied Sciences, St. Joseph University in Tanzania, Dar es Salaam P.O. Box 11007, Tanzania
| | - Jahashi Nzalawahe
- Department of Veterinary Microbiology, Parasitology and Biotechnology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro P.O. Box 3019, Tanzania; (J.N.); (G.M.); (E.M.)
| | - Gerald Misinzo
- Department of Veterinary Microbiology, Parasitology and Biotechnology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro P.O. Box 3019, Tanzania; (J.N.); (G.M.); (E.M.)
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro P.O. Box 3297, Tanzania
| | - Humphrey D. Mazigo
- Department of Medical Parasitology, School of Medicine, Catholic University of Health and Allied Sciences, Mwanza P.O. Box 1464, Tanzania; (H.D.M.); (N.C.J.); (N.B.)
| | - Matthieu Briet
- µFlow Group, Department of Chemical Engineering, Vrije Universiteit Brussel, 1050 Brussels, Belgium; (M.B.); (V.R.M.); (F.L.)
| | - Vyacheslav R. Misko
- µFlow Group, Department of Chemical Engineering, Vrije Universiteit Brussel, 1050 Brussels, Belgium; (M.B.); (V.R.M.); (F.L.)
| | - Wim De Malsche
- µFlow Group, Department of Chemical Engineering, Vrije Universiteit Brussel, 1050 Brussels, Belgium; (M.B.); (V.R.M.); (F.L.)
| | - Filip Legein
- µFlow Group, Department of Chemical Engineering, Vrije Universiteit Brussel, 1050 Brussels, Belgium; (M.B.); (V.R.M.); (F.L.)
| | - Nyanda C. Justine
- Department of Medical Parasitology, School of Medicine, Catholic University of Health and Allied Sciences, Mwanza P.O. Box 1464, Tanzania; (H.D.M.); (N.C.J.); (N.B.)
| | - Namanya Basinda
- Department of Medical Parasitology, School of Medicine, Catholic University of Health and Allied Sciences, Mwanza P.O. Box 1464, Tanzania; (H.D.M.); (N.C.J.); (N.B.)
| | - Eliakunda Mafie
- Department of Veterinary Microbiology, Parasitology and Biotechnology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro P.O. Box 3019, Tanzania; (J.N.); (G.M.); (E.M.)
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Lehnert T, Gijs MAM. Microfluidic systems for infectious disease diagnostics. LAB ON A CHIP 2024; 24:1441-1493. [PMID: 38372324 DOI: 10.1039/d4lc00117f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Microorganisms, encompassing both uni- and multicellular entities, exhibit remarkable diversity as omnipresent life forms in nature. They play a pivotal role by supplying essential components for sustaining biological processes across diverse ecosystems, including higher host organisms. The complex interactions within the human gut microbiota are crucial for metabolic functions, immune responses, and biochemical signalling, particularly through the gut-brain axis. Viruses also play important roles in biological processes, for example by increasing genetic diversity through horizontal gene transfer when replicating inside living cells. On the other hand, infection of the human body by microbiological agents may lead to severe physiological disorders and diseases. Infectious diseases pose a significant burden on global healthcare systems, characterized by substantial variations in the epidemiological landscape. Fast spreading antibiotic resistance or uncontrolled outbreaks of communicable diseases are major challenges at present. Furthermore, delivering field-proven point-of-care diagnostic tools to the most severely affected populations in low-resource settings is particularly important and challenging. New paradigms and technological approaches enabling rapid and informed disease management need to be implemented. In this respect, infectious disease diagnostics taking advantage of microfluidic systems combined with integrated biosensor-based pathogen detection offers a host of innovative and promising solutions. In this review, we aim to outline recent activities and progress in the development of microfluidic diagnostic tools. Our literature research mainly covers the last 5 years. We will follow a classification scheme based on the human body systems primarily involved at the clinical level or on specific pathogen transmission modes. Important diseases, such as tuberculosis and malaria, will be addressed more extensively.
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Affiliation(s)
- Thomas Lehnert
- Laboratory of Microsystems, École Polytechnique Fédérale de Lausanne, Lausanne, CH-1015, Switzerland.
| | - Martin A M Gijs
- Laboratory of Microsystems, École Polytechnique Fédérale de Lausanne, Lausanne, CH-1015, Switzerland.
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Mazigo HD, Justine NC, Bhuko J, Rubagumya S, Basinda N, Zinga MM, Ruganuza D, Misko VR, Briet M, Legein F, De Malsche W. High Specificity but Low Sensitivity of Lab-on-a-Disk Technique in Detecting Soil-Transmitted Helminth Eggs among Pre- and School-Aged Children in North-Western Tanzania. Trop Med Infect Dis 2023; 9:5. [PMID: 38276635 PMCID: PMC10818991 DOI: 10.3390/tropicalmed9010005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 12/15/2023] [Accepted: 12/18/2023] [Indexed: 01/27/2024] Open
Abstract
An estimated 1.5 billion people are infected with soil-transmitted helminths (hookworms, Ascaris lumbricoides and Trichuris trichiura). These infections are targeted for elimination by the World Health Organization (WHO) by 2030, with the main interventions being mass drug administration using albendazole or mebendazole. Tanzania is one of the endemic countries; it has been implementing MDA to school-aged children for more than a decade and the infection prevalence and intensity of infection have declined. Thus, at this point, the monitoring and evaluation of infection prevalence and intensity of infections, and assessing drug efficacy is crucial and requires accurate diagnostic tests. The currently used standard diagnostic test, the Kato-Katz (KK) technique, has several limitations and the WHO is calling for the development and evaluation of new diagnostic tests. The Lab-on-a-disk (LOD) was developed and tested in the endemic areas of north-western Tanzania to evaluate its sensitivity and specificity using KK and the formol-ether concentration technique. The results showed that when using a duplicate KK slide, the LOD had a sensitivity and specificity of 37.2% (95% CI: 30.7-43.9) and 67.3% (95% CI: 63.1-71.3%). Using four KK slides as a standard technique, the overall sensitivity and specificity were 37.7% (95% CI: 33.1-42.6) and 70.7% (95% CI: 65.5-75.6). The LOD attained high specificity but low sensitivity especially in detecting eggs of Trichuris trichiura. The LOD technique has potential as a promising diagnostic test, but its sensitivity still requires improvement.
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Affiliation(s)
- Humphrey D. Mazigo
- Department of Medical Parasitology and Entomology, School of Medicine, Catholic University of Health and Allied Sciences, Mwanza P.O. Box 1464, Tanzania; (N.C.J.); (J.B.); (M.M.Z.); (D.R.)
| | - Nyanda C. Justine
- Department of Medical Parasitology and Entomology, School of Medicine, Catholic University of Health and Allied Sciences, Mwanza P.O. Box 1464, Tanzania; (N.C.J.); (J.B.); (M.M.Z.); (D.R.)
| | - Jeffer Bhuko
- Department of Medical Parasitology and Entomology, School of Medicine, Catholic University of Health and Allied Sciences, Mwanza P.O. Box 1464, Tanzania; (N.C.J.); (J.B.); (M.M.Z.); (D.R.)
| | - Sarah Rubagumya
- Department of Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Chuo Kikuu, Morogoro P.O. Box 3000, Tanzania;
| | - Namanya Basinda
- Department of Community Medicine, School of Public Health, Catholic University of Health and Allied Sciences, Mwanza P.O. Box 1464, Tanzania;
| | - Maria M. Zinga
- Department of Medical Parasitology and Entomology, School of Medicine, Catholic University of Health and Allied Sciences, Mwanza P.O. Box 1464, Tanzania; (N.C.J.); (J.B.); (M.M.Z.); (D.R.)
| | - Deodatus Ruganuza
- Department of Medical Parasitology and Entomology, School of Medicine, Catholic University of Health and Allied Sciences, Mwanza P.O. Box 1464, Tanzania; (N.C.J.); (J.B.); (M.M.Z.); (D.R.)
| | - Vyacheslav R. Misko
- µFlow Group, Department of Bioengineering Sciences, Vrije Universiteit Brussel, 1050 Brussels, Belgium; (V.R.M.); (M.B.); (F.L.)
| | - Matthieu Briet
- µFlow Group, Department of Bioengineering Sciences, Vrije Universiteit Brussel, 1050 Brussels, Belgium; (V.R.M.); (M.B.); (F.L.)
| | - Filip Legein
- µFlow Group, Department of Bioengineering Sciences, Vrije Universiteit Brussel, 1050 Brussels, Belgium; (V.R.M.); (M.B.); (F.L.)
| | - Wim De Malsche
- µFlow Group, Department of Bioengineering Sciences, Vrije Universiteit Brussel, 1050 Brussels, Belgium; (V.R.M.); (M.B.); (F.L.)
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Elghryani N, McAloon C, Mincher C, McOwan T, de Waal T. Comparison of the Automated OvaCyte Telenostic Faecal Analyser versus the McMaster and Mini-FLOTAC Techniques in the Estimation of Helminth Faecal Egg Counts in Equine. Animals (Basel) 2023; 13:3874. [PMID: 38136911 PMCID: PMC10740962 DOI: 10.3390/ani13243874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/11/2023] [Accepted: 12/13/2023] [Indexed: 12/24/2023] Open
Abstract
Gastrointestinal helminth parasites continue to be a significant threat to the health of equine. OvaCyte Telenostic (OCT) (Telenostic Ltd., Kilkenny, Ireland) has developed an automated digital microscope utilising Artificial Intelligence to identify and count the clinically important helminth species in equine, bovine, and ovine host species. In this paper, the performance of the OCT analyser was evaluated for the detection and counting of equine helminth species parasites and its performance compared to the currently accepted benchmark methods of faecal egg counts being the McMaster and the Mini-FLOTAC techniques. A pairwise comparison of tests was assessed based on the correlation of egg counts and Cohen's kappa agreement statistics for dichotomized outcomes. Bayesian latent class analysis was used to estimate the sensitivity and specificity of all three techniques in the absence of a gold standard for four helminth parasites (strongyles, Anoplocephala spp., Parascaris spp. and Strongyloides westeri). Based on the analysis of 783 equine faecal samples, we found a high level (ρ ≥ 0.94) of correlation between each pairwise comparison of techniques for strongyle egg counts. Cohen's kappa agreement between techniques was high for strongyles and S. westeri, moderate for Parascaris spp., and low for Anoplocephala spp. All three techniques had a high sensitivity and specificity (>0.90) for strongyles. Across helminth parasites, the sensitivity of the OCT was the highest of the three techniques evaluated for strongyles (0.98 v 0.96 and 0.94), Anoplocephala spp. (0.86 v 0.44 and 0.46) and Parascaris spp. (0.96 v 0.83 and 0.96); but lowest for S. westeri (0.74 v 0.88 and 0.88), compared to McMaster and Mini-FLOTAC, respectively. In terms of specificity, OCT was the lowest in two species (Parascaris spp. 0.96, Anoplocephala spp. 0.95). In conclusion, OCT has a sensitivity and specificity statistically similar to both McMaster and Mini-FLOTAC, and had a higher correlation with Mini-FLOTAC. The OCT point of care faecal analyser offers improved workflow, test turn-around time and does not require trained laboratory personnel to operate or interpret the results.
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Affiliation(s)
- Nagwa Elghryani
- Telenostic Limited, R95 WN20 Kilkenny, Ireland; (C.M.); (T.M.)
- Department of Biology, Faculty ofSciences-Qumnis, University of Benghazi, Benghazi 1308, Libya
- School of Veterinary Medicine, University College Dublin, D04 D6F6 Dublin, Ireland; (C.M.); (T.d.W.)
| | - Conor McAloon
- School of Veterinary Medicine, University College Dublin, D04 D6F6 Dublin, Ireland; (C.M.); (T.d.W.)
| | - Craig Mincher
- Telenostic Limited, R95 WN20 Kilkenny, Ireland; (C.M.); (T.M.)
| | - Trish McOwan
- Telenostic Limited, R95 WN20 Kilkenny, Ireland; (C.M.); (T.M.)
| | - Theo de Waal
- School of Veterinary Medicine, University College Dublin, D04 D6F6 Dublin, Ireland; (C.M.); (T.d.W.)
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Misko VR, Makasali RJ, Briet M, Legein F, Levecke B, De Malsche W. Enhancing the Yield of a Lab-on-a-Disk-Based Single-Image Parasite Quantification Device. MICROMACHINES 2023; 14:2087. [PMID: 38004944 PMCID: PMC10672913 DOI: 10.3390/mi14112087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/03/2023] [Accepted: 11/09/2023] [Indexed: 11/26/2023]
Abstract
The recently proposed single-image parasite quantification (SIMPAQ) platform based on a Lab-on-a-Disc (LOD) device was previously successfully tested in field conditions, demonstrating its efficiency in soil-transmitted helminth (STH) egg detection and analysis on the level delivered by the current state-of-the-art methods. Furthermore, the SIMPAQ provides relatively quick diagnostics and requires small amounts of sample and materials. On the other hand, in a recent related study, it was revealed that the performance of the SIMPAQ method can be limited due to the action of the tangential Euler and Coriolis forces, and the interaction of the moving eggs with the walls of the LOD chamber. Here, we propose a new improved design that allows us to overcome these limitations and enhance the yield of the SIMPAQ LOD device, as demonstrated in experiments with a synthetic particle model system and real parasite eggs. Despite the simplicity, the proposed design modification is demonstrated to allow a substantial improvement in the yield of the SIMPAQ device, i.e., above 90% of parasite eggs and 98% of synthetic model particles were transported to the field of view. The new design proposed here will be further examined in the new generation of SIMPAQ devices within ongoing research on STH egg detection in field conditions.
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Affiliation(s)
- Vyacheslav R. Misko
- µFlow Group, Department of Chemical Engineering, Vrije Universiteit Brussel, 1050 Brussels, Belgium; (V.R.M.); (R.J.M.); (M.B.); (F.L.)
| | - Ramadhani Juma Makasali
- µFlow Group, Department of Chemical Engineering, Vrije Universiteit Brussel, 1050 Brussels, Belgium; (V.R.M.); (R.J.M.); (M.B.); (F.L.)
| | - Matthieu Briet
- µFlow Group, Department of Chemical Engineering, Vrije Universiteit Brussel, 1050 Brussels, Belgium; (V.R.M.); (R.J.M.); (M.B.); (F.L.)
| | - Filip Legein
- µFlow Group, Department of Chemical Engineering, Vrije Universiteit Brussel, 1050 Brussels, Belgium; (V.R.M.); (R.J.M.); (M.B.); (F.L.)
| | - Bruno Levecke
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, 9820 Merelbeke, Belgium;
| | - Wim De Malsche
- µFlow Group, Department of Chemical Engineering, Vrije Universiteit Brussel, 1050 Brussels, Belgium; (V.R.M.); (R.J.M.); (M.B.); (F.L.)
- Department of Bioengineering Sciences, Vrije Universiteit Brussel, 1050 Brussels, Belgium
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A review on innovative optical devices for the diagnosis of human soil-transmitted helminthiasis and schistosomiasis: from research and development to commercialization. Parasitology 2023; 150:137-149. [PMID: 36683384 PMCID: PMC10090604 DOI: 10.1017/s0031182022001664] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Diagnosis of soil-transmitted helminth (STH) and schistosome infections relies largely on conventional microscopy which has limited sensitivity, requires highly trained personnel and is error-prone. Rapid advances in miniaturization of optical systems, sensors and processors have enhanced research and development of digital and automated microscopes suitable for the detection of these diseases in resource-limited settings. While some studies have reported proof-of-principle results, others have evaluated the performance of working prototypes in field settings. The extensive commercialization of these innovative devices has, however, not yet been achieved. This review provides an overview of recent publications (2010–2022) on innovative field applicable optical devices which can be used for the diagnosis of STH and schistosome infections. Using an adapted technology readiness level (TRL) scale taking into account the WHO target product profile (TPP) for these diseases, the developmental stages of the devices were ranked to determine the readiness for practical applications in field settings. From the reviewed 18 articles, 19 innovative optical devices were identified and ranked. Almost all of the devices (85%) were ranked with a TRL score below 8 indicating that, most of the devices are not ready for commercialization and field use. The potential limitations of these innovative devices were discussed. We believe that the outcome of this review can guide the end-to-end development of automated digital microscopes aligned with the WHO TPP for the diagnosis of STH and schistosome infections in resource-limited settings.
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Rinaldi L, Krücken J, Martinez-Valladares M, Pepe P, Maurelli MP, de Queiroz C, Castilla Gómez de Agüero V, Wang T, Cringoli G, Charlier J, Gilleard JS, von Samson-Himmelstjerna G. Advances in diagnosis of gastrointestinal nematodes in livestock and companion animals. ADVANCES IN PARASITOLOGY 2022; 118:85-176. [PMID: 36088084 DOI: 10.1016/bs.apar.2022.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Diagnosis of gastrointestinal nematodes in livestock and companion animals has been neglected for years and there has been an historical underinvestment in the development and improvement of diagnostic tools, undermining the undoubted utility of surveillance and control programmes. However, a new impetus by the scientific community and the quickening pace of technological innovations, are promoting a renaissance of interest in developing diagnostic capacity for nematode infections in veterinary parasitology. A cross-cutting priority for diagnostic tools is the development of pen-side tests and associated decision support tools that rapidly inform on the levels of infection and morbidity. This includes development of scalable, parasite detection using artificial intelligence for automated counting of parasitic elements and research towards establishing biomarkers using innovative molecular and proteomic methods. The aim of this review is to assess the state-of-the-art in the diagnosis of helminth infections in livestock and companion animals and presents the current advances of diagnostic methods for intestinal parasites harnessing (i) automated methods for copromicroscopy based on artificial intelligence, (ii) immunodiagnosis, and (iii) molecular- and proteome-based approaches. Regardless of the method used, multiple factors need to be considered before diagnostics test results can be interpreted in terms of control decisions. Guidelines on how to apply diagnostics and how to interpret test results in different animal species are increasingly requested and some were recently made available in veterinary parasitology for the different domestic species.
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Affiliation(s)
- Laura Rinaldi
- Department of Veterinary Medicine and Animal Production, University of Naples "Federico II", Naples, Italy.
| | - J Krücken
- Institute for Parasitology and Tropical Veterinary Medicine, Veterinary Centre for Resistance Research, Freie Universität Berlin, Berlin, Germany
| | - M Martinez-Valladares
- Instituto de Ganadería de Montaña (CSIC-Universidad de León), Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, León, Spain
| | - P Pepe
- Department of Veterinary Medicine and Animal Production, University of Naples "Federico II", Naples, Italy
| | - M P Maurelli
- Department of Veterinary Medicine and Animal Production, University of Naples "Federico II", Naples, Italy
| | - C de Queiroz
- Faculty of Veterinary Medicine, 3331 Hospital Drive, Host-Parasite Interactions (HPI) Program University of Calgary, Calgary, Alberta, Canada; Faculty of Veterinary Medicine, St Georges University, Grenada
| | - V Castilla Gómez de Agüero
- Instituto de Ganadería de Montaña (CSIC-Universidad de León), Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, León, Spain
| | - T Wang
- Kreavet, Kruibeke, Belgium
| | - Giuseppe Cringoli
- Department of Veterinary Medicine and Animal Production, University of Naples "Federico II", Naples, Italy
| | | | - J S Gilleard
- Faculty of Veterinary Medicine, 3331 Hospital Drive, Host-Parasite Interactions (HPI) Program University of Calgary, Calgary, Alberta, Canada
| | - G von Samson-Himmelstjerna
- Institute for Parasitology and Tropical Veterinary Medicine, Veterinary Centre for Resistance Research, Freie Universität Berlin, Berlin, Germany
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Papaiakovou M, Littlewood DTJ, Doyle SR, Gasser RB, Cantacessi C. Worms and bugs of the gut: the search for diagnostic signatures using barcoding, and metagenomics-metabolomics. Parasit Vectors 2022; 15:118. [PMID: 35365192 PMCID: PMC8973539 DOI: 10.1186/s13071-022-05225-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 02/25/2022] [Indexed: 02/07/2023] Open
Abstract
Gastrointestinal (GI) helminth infections cause significant morbidity in both humans and animals worldwide. Specific and sensitive diagnosis is central to the surveillance of such infections and to determine the effectiveness of treatment strategies used to control them. In this article, we: (i) assess the strengths and limitations of existing methods applied to the diagnosis of GI helminth infections of humans and livestock; (ii) examine high-throughput sequencing approaches, such as targeted molecular barcoding and shotgun sequencing, as tools to define the taxonomic composition of helminth infections; and (iii) discuss the current understanding of the interactions between helminths and microbiota in the host gut. Stool-based diagnostics are likely to serve as an important tool well into the future; improved diagnostics of helminths and their environment in the gut may assist the identification of biomarkers with the potential to define the health/disease status of individuals and populations, and to identify existing or emerging anthelmintic resistance.
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Affiliation(s)
- Marina Papaiakovou
- Department of Veterinary Medicine, University of Cambridge, Cambridge, CB3 0ES UK
- Department of Life Sciences, Natural History Museum, Cromwell Road, London, SW7 5BD UK
| | | | | | - Robin B. Gasser
- Melbourne Veterinary School, The University of Melbourne, Parkville, VIC 3010 Australia
| | - Cinzia Cantacessi
- Department of Veterinary Medicine, University of Cambridge, Cambridge, CB3 0ES UK
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Charlier J, Bartley DJ, Sotiraki S, Martinez-Valladares M, Claerebout E, von Samson-Himmelstjerna G, Thamsborg SM, Hoste H, Morgan ER, Rinaldi L. Anthelmintic resistance in ruminants: challenges and solutions. ADVANCES IN PARASITOLOGY 2022; 115:171-227. [PMID: 35249662 DOI: 10.1016/bs.apar.2021.12.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Anthelmintic resistance (AR) is a growing concern for effective parasite control in farmed ruminants globally. Combatting AR will require intensified and integrated research efforts in the development of innovative diagnostic tests to detect helminth infections and AR, sustainable anthelmintic treatment strategies and the development of complementary control approaches such as vaccination and plant-based control. It will also require a better understanding of socio-economic drivers of anthelmintic treatment decisions, in order to support a behavioural shift and develop targeted communication strategies that promote the uptake of evidence-based sustainable solutions. Here, we review the state-of-the-art in these different fields of research activity related to AR in helminths of livestock ruminants in Europe and beyond. We conclude that in the advent of new challenges and solutions emerging from continuing spread of AR and intensified research efforts, respectively, there is a strong need for transnational multi-actor initiatives. These should involve all key stakeholders to develop indicators of infection and sustainable control, set targets and promote good practices to achieve them.
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Affiliation(s)
| | - D J Bartley
- Disease Control, Moredun Research Institute, Penicuik, United Kingdom
| | - S Sotiraki
- Veterinary Research Institute, Hellenic Agricultural Organisation ELGO-DIMITRA, Thessaloniki, Greece
| | - M Martinez-Valladares
- Instituto de Ganadería de Montaña (CSIC-Universidad de León), Departamento de Sanidad Animal, León, Spain
| | - E Claerebout
- Ghent University, Faculty of Veterinary Medicine, Laboratory of Parasitology, Merelbeke, Belgium
| | - G von Samson-Himmelstjerna
- Institute for Parasitology and Tropical Veterinary Medicine, Veterinary Centre for Resistance Research, Freie Universität Berlin, Berlin, Germany
| | - S M Thamsborg
- Veterinary Parasitology, University of Copenhagen, Frederiksberg C, Denmark
| | - H Hoste
- INRAE, UMR 1225 IHAP INRAE/ENVT, Toulouse University, Toulouse, France
| | - E R Morgan
- Institute for Global Food Security, Queen's University Belfast, Belfast, United Kingdom
| | - L Rinaldi
- University of Naples Federico II, Unit of Parasitology and Parasitic Diseases, Department of Veterinary Medicine and Animal Production, CREMOPAR, Napoli, Italy.
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11
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Nielsen MK, Doran D, Slusarewicz P. Effects of sample homogenizing on the performance of an automated strongylid egg counting system. Vet Parasitol 2021; 300:109623. [PMID: 34837877 DOI: 10.1016/j.vetpar.2021.109623] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/15/2021] [Accepted: 11/20/2021] [Indexed: 10/19/2022]
Abstract
Fecal egg counts are essential monitoring tools in veterinary parasite control. In recent years, several groups have developed automated egg counting systems based on image analysis and deep learning algorithms. Work in our laboratory demonstrated that an automated system performed with significantly better precision than traditional egg counting techniques. However, while the counting process is no longer operator dependent, the pre-analytical homogenization steps still are. This study aimed at evaluating the influence of sample homogenization on diagnostic performance on an automated equine strongylid egg counting system. Samples were collected from 12 horses and assigned to three egg count categories (four samples per category): Low (0-500 eggs per gram (EPG)), Moderate (501-1000 EPG), and High (1001-2000 EPG). Within each category, all samples were divided into four portions and each was analyzed with the automated system using the following four homogenizing procedures using a homogenizing device supplied with the system: 1) pressing the plunger five times and pouring directly into the counting chamber, 2) pressing the plunger five times and shaking the bottle prior to pouring, 3) pressing the plunger ten times with direct pouring, and 4) pressing the plunger ten times with shaking the bottle before pouring. There were no differences in precision expressed as coefficient of variation between these four procedures but shaking of the bottle prior to pouring was significantly associated with higher counts (p = 0.0068). These results demonstrate that the homogenization process can affect the diagnostic performance of an automated egg counting system and suggest that more efforts should be invested in standardizing and optimizing homogenization procedures.
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Affiliation(s)
- Martin K Nielsen
- M.H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, USA.
| | - Daniel Doran
- College of Veterinary Medicine, Lincoln Memorial University, Harrogate, TN, USA
| | - Paul Slusarewicz
- MEP Equine Solutions, 3905 English Oak Circle, Lexington, KY, USA
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12
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Maurelli MP, Alves LC, Aggarwal CS, Cociancic P, Levecke B, Cools P, Montresor A, Ianniello D, Gualdieri L, Cringoli G, Rinaldi L. Ascaris lumbricoides eggs or artefacts? A diagnostic conundrum. Parasitology 2021; 148:1554-1559. [PMID: 34250886 PMCID: PMC8564801 DOI: 10.1017/s0031182021001256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 06/29/2021] [Accepted: 07/04/2021] [Indexed: 11/24/2022]
Abstract
Due to the presence of artefacts in stool samples, the copromicroscopic diagnosis of Ascaris lumbricoides is not always straightforward, particularly in the case of fertilized decorticated eggs. A total of 286 stool samples from 115 schoolchildren in India and 171 adult immigrants in Italy were screened for the presence of A. lumbricoides eggs by both Kato-Katz thick smear and Mini-FLOTAC. If the outer layer of A. lumbricoides eggs was absent, two aliquots of each stool sample were preserved: one for coproculture to identify larvae after development and one to compose a pool of stool for molecular analysis. A total of 64 stool samples (22.4%) were positive for A. lumbricoides using the Kato-Katz thick smear; 36 (56.3%) of these showed mammillated A. lumbricoides eggs, 25 (39.1%) showed elements resembling fertilized decorticated eggs, while three samples (4.7%) showed both mammillated and decorticated eggs. By Mini-FLOTAC, 39 stool samples (13.6%) were positive, while decorticated A. lumbricoides-like eggs were identified as artefacts. These results were confirmed by negative coprocultures and quantitative polymerase chain reaction. Mini-FLOTAC can be used for a reliable diagnosis of A. lumbricoides, thanks to the flotation and translation features which allow a clearer view, resulting in the correct identification of A. lumbricoides eggs.
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Affiliation(s)
- M. P. Maurelli
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, CREMOPAR, WHO Collaborating Centre ITA-116, Naples, Italy
| | - L. C. Alves
- Department of Veterinary Medicine, Federal Rural University of Pernambuco, Recife, Brazil
| | - C. S. Aggarwal
- Division of Parasitic Diseases, National Centre for Disease Control, 22 Shamnath Marg, Delhi, India
| | - P. Cociancic
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, CREMOPAR, WHO Collaborating Centre ITA-116, Naples, Italy
- Centro de Estudios Parasitológicos y de Vectores (CEPAVE-CONICET-UNLP-asociado a CICPBA), La Plata, Buenos Aires, Argentina
| | - B. Levecke
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, WHO Collaborating Centre BEL-42, Merelbeke, Belgium
| | - P. Cools
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, WHO Collaborating Centre BEL-42, Merelbeke, Belgium
| | - A. Montresor
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
| | - D. Ianniello
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, CREMOPAR, WHO Collaborating Centre ITA-116, Naples, Italy
| | - L. Gualdieri
- Medical Center, Centro per la Tutela della Salute degli Immigrati, Naples, Italy
| | - G. Cringoli
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, CREMOPAR, WHO Collaborating Centre ITA-116, Naples, Italy
| | - L. Rinaldi
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, CREMOPAR, WHO Collaborating Centre ITA-116, Naples, Italy
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Migration Behavior of Low-Density Particles in Lab-on-a-Disc Devices: Effect of Walls. MICROMACHINES 2021; 12:mi12091032. [PMID: 34577676 PMCID: PMC8471521 DOI: 10.3390/mi12091032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/25/2021] [Accepted: 08/25/2021] [Indexed: 11/17/2022]
Abstract
The effect of the lateral walls of a Lab-On-a-Disc device on the dynamics of a model system of particles with a density lower than that of the solvent (modelling parasites eggs) is analyzed theoretically and experimentally. In the absence of lateral walls, a particle always moves in the direction of the centrifugal force, while its trajectory is deflected in the tangential direction by the inertial Coriolis and Euler forces. Lateral walls, depending on the angle forming with the radial direction, can guide the particle either in the same or in the opposite direction to the centrifugal force, thus resulting in unusual particle trajectories including zig-zag or backwards particle motion. The effect is pronounced in the case of short operation times when the acceleration of the angular rotation, and thus the Euler force, is considerable. The predicted unusual motion is demonstrated by numerically solving the equation of motion in the presence of lateral walls and verified in the experiment with particles of density lower than that of the solvent. Our analysis is useful for design and operational considerations of Lab-On-a-Disc devices aiming for or involving (bio)particle handling.
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Hoekstra PT, van Dam GJ, van Lieshout L. Context-Specific Procedures for the Diagnosis of Human Schistosomiasis – A Mini Review. FRONTIERS IN TROPICAL DISEASES 2021. [DOI: 10.3389/fitd.2021.722438] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Schistosomiasis is a parasitic disease caused by trematode blood flukes of the genus Schistosoma, affecting over 250 million people mainly in the tropics. Clinically, the disease can present itself with acute symptoms, a stage which is relatively more common in naive travellers originating from non-endemic regions. It can also develop into chronic disease, with the outcome depending on the Schistosoma species involved, the duration and intensity of infection and several host-related factors. A range of diagnostic tests is available to determine Schistosoma infection, including microscopy, antibody detection, antigen detection using the Point-Of-Care Circulating Cathodic Antigen (POC-CCA) test and the Up-Converting Particle Lateral Flow Circulating Anodic Antigen (UCP-LF CAA) test, as well as Nucleic Acid Amplification Tests (NAATs) such as real-time PCR. In this mini review, we discuss these different diagnostic procedures and explore their most appropriate use in context-specific settings. With regard to endemic settings, diagnostic approaches are described based on their suitability for individual diagnosis, monitoring control programs, determining elimination as a public health problem and eventual interruption of transmission. For non-endemic settings, we summarize the most suitable diagnostic approaches for imported cases, either acute or chronic. Additionally, diagnostic options for disease-specific clinical presentations such as genital schistosomiasis and neuro-schistosomiasis are included. Finally, the specific role of diagnostic tests within research settings is described, including a controlled human schistosomiasis infection model and several clinical studies. In conclusion, context-specific settings have different requirements for a diagnostic test, stressing the importance of a well-considered decision of the most suitable diagnostic procedure.
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15
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Khurana S, Singh S, Mewara A. Diagnostic Techniques for Soil-Transmitted Helminths - Recent Advances. Res Rep Trop Med 2021; 12:181-196. [PMID: 34377048 PMCID: PMC8349539 DOI: 10.2147/rrtm.s278140] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 07/01/2021] [Indexed: 12/26/2022] Open
Abstract
Soil-transmitted helminth (STH) infections (hookworms, Trichuris, Ascaris) and Strongyloides spp. are associated with a substantial global burden and high morbidity. Sensitive and specific methods for diagnosis of these infections are essential for mapping the burden in communities, accurate assessment of infection levels, to guide interventions and monitoring the success of STH control programs. Despite considerable progress to control STH over several decades, we are still far from identifying a fully adequate diagnostic test. Conventional microscopy-based methods such as direct Kato–Katz smear or mounts after stool centrifugation/flotation-based concentration techniques have been the mainstay of diagnosis, especially in resource-poor countries where these infections abound. However, recently, these are being adapted to closed, easy to perform, digital formats, thereby improving the sensitivity as well as applicability in a remote, resource-limited setting. The use of image analysis systems to identify and quantify helminth eggs, with potential adaptation to smartphones, is also promising. Antibody detection tests have a limited role mostly in the case of Strongyloides hyperinfection. Coproantigen detection tests have been developed and used in veterinary practice for detection of STH, but these have not been evaluated for use in humans. More sensitive molecular diagnostics, including assays developed with new bioinformatic tools and techniques such as polymerase chain reaction (PCR), quantitative PCR (qPCR) and loop-mediated amplification assay, can help in the clear and precise assessment of STH burden during elimination phase and are of immense value for diagnosis in areas with low endemicity and in travelers to endemic regions. Moreover, the molecular techniques will help detect new species that may emerge. Sample preservation and efficient DNA extraction are critical and significantly affect the efficiency of molecular diagnostic tests. In addition to the diagnosis of clinical or asymptomatic infection in humans, detection of STH eggs in environmental samples is imperative to boost STH control efforts. Overall the diagnostic performance, cost-effectiveness, ease of performance, rapidity and in-field applicability of any test should be considered when choosing from the various diagnostic assays in areas with different endemicity, in addition to striving towards the development of novel technologies and optimization of existing methods.
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Affiliation(s)
- Sumeeta Khurana
- Department of Medical Parasitology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Shreya Singh
- Department of Medical Microbiology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Abhishek Mewara
- Department of Medical Parasitology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
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16
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Nielsen MK. What makes a good fecal egg count technique? Vet Parasitol 2021; 296:109509. [PMID: 34218175 DOI: 10.1016/j.vetpar.2021.109509] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 06/19/2021] [Accepted: 06/23/2021] [Indexed: 11/28/2022]
Abstract
The first parasite fecal egg counting techniques were described over 100 years ago, and fecal egg counting remains essential in parasitology research as well as in clinical practice today. Several novel techniques have been introduced and validated in recent years, but this work has also highlighted several current issues in this research field. There is a lack of consensus on which diagnostic parameters to evaluate and how to properly design studies doing so. Furthermore, there is a confusing and sometimes incorrect use of terminology describing performance of fecal egg counting techniques, and it would be helpful to address these. This manuscript reviews qualitative and quantitative diagnostic performance parameters, discusses their relevance for fecal egg counting techniques, and highlights some of the challenges with determining them. Qualitative parameters such as diagnostic sensitivity and specificity may be considered classic diagnostic performance metrics, but they generally only have implications at low egg count levels. The detection limit of a given technique is often referred to as the "analytical sensitivity", but this is misleading as the detection limit is a theoretically derived number, whereas analytical sensitivity is determined experimentally. Thus, the detection limit is not a diagnostic performance parameter and does not inform on the diagnostic sensitivity of a technique. Quantitative performance parameters such as accuracy and precision are highly relevant for describing the performance of fecal egg counting techniques, and precision is arguably the more important of the two. An absolute determination of accuracy can only be achieved by use of samples spiked with known quantities of parasite ova, but spiking does not necessarily mimic the true distribution of eggs within a sample, and accuracy estimates are difficult to reproduce between laboratories. Instead, analysis of samples from naturally infected animals can be used to achieve a relative ranking of techniques according to egg count magnitude. Precision can be estimated in a number of different approaches, but it is important to ensure a relevant representation of egg count levels in the study sample set, as low egg counts tend to associate with lower precision estimates. Coefficients of variation generally provide meaningful measures of precision that are independent of the multiplication factor of the techniques evaluated. Taken together, there is a need for clear guidelines for studies validating fecal egg counting techniques in veterinary parasitology with emphasis on what should be evaluated, how studies could be designed, and how to appropriately analyze the data. Furthermore, there is a clear need for better consensus regarding use of terminology describing the diagnostic performance of fecal egg count techniques.
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Affiliation(s)
- Martin K Nielsen
- M.H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, USA.
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The role of diagnostic technologies to measure progress toward WHO 2030 targets for soil-transmitted helminth control programs. PLoS Negl Trop Dis 2021; 15:e0009422. [PMID: 34081694 PMCID: PMC8174700 DOI: 10.1371/journal.pntd.0009422] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Ghafar A, Abbas G, King J, Jacobson C, Hughes KJ, El-Hage C, Beasley A, Bauquier J, Wilkes EJ, Hurley J, Cudmore L, Carrigan P, Tennent-Brown B, Nielsen MK, Gauci CG, Beveridge I, Jabbar A. Comparative studies on faecal egg counting techniques used for the detection of gastrointestinal parasites of equines: A systematic review. CURRENT RESEARCH IN PARASITOLOGY & VECTOR-BORNE DISEASES 2021; 1:100046. [PMID: 35284858 PMCID: PMC8906068 DOI: 10.1016/j.crpvbd.2021.100046] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 08/02/2021] [Accepted: 08/03/2021] [Indexed: 11/04/2022]
Abstract
Faecal egg counting techniques (FECT) form the cornerstone for the detection of gastrointestinal parasites in equines. For this purpose, several flotation, centrifugation, image- and artificial intelligence-based techniques are used, with varying levels of performance. This review aimed to critically appraise the literature on the assessment and comparison of various coprological techniques and/or modifications of these techniques used for equines and to identify the knowledge gaps and future research directions. We searched three databases for published scientific studies on the assessment and comparison of FECT in equines and included 27 studies in the final synthesis. Overall, the performance parameters of McMaster (81.5%), Mini-FLOTAC® (33.3%) and simple flotation (25.5%) techniques were assessed in most of the studies, with 77.8% of them comparing the performance of at least two or three methods. The detection of strongyle, Parascaris spp. and cestode eggs was assessed for various FECT in 70.4%, 18.5% and 18.5% studies, respectively. A sugar-based flotation solution with a specific gravity of ≥1.2 was found to be the optimal flotation solution for parasitic eggs in the majority of FECT. No uniform or standardised protocol was followed for the comparison of various FECT, and the tested sample size (i.e. equine population and faecal samples) also varied substantially across all studies. To the best of our knowledge, this is the first systematic review to evaluate studies on the comparison of FECT in equines and it highlights important knowledge gaps in the evaluation and comparison of such techniques. An assessment of studies on the comparison of faecal egg counting in equine parasitology was undertaken. A consensus on the methodology and performance parameters for faecal egg counting techniques is required. Technical and biological sources of variability in faecal egg counts should be considered. Minimum analytical and diagnostic performance parameters should be assessed.
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Abstract
The Kubic FLOTAC microscope (KFM) is a compact, low-cost, versatile and portable digital microscope designed to analyse fecal specimens prepared with Mini-FLOTAC or FLOTAC, in both field and laboratory settings. In this paper, we present the characteristics of the KFM along with its first validation for fecal egg count (FEC) of gastrointestinal nematodes (GINs) in cattle. For this latter purpose, a study was performed on 30 fecal samples from cattle experimentally infected by GINs to compare the performance of Mini-FLOTAC either using a traditional optical microscope (OM) or the KFM. The results of the comparison showed a substantial agreement (concordance correlation coefficient = 0.999), with a very low discrepancy (−0.425 ± 7.370) between the two microscopes. Moreover, the KFM captured images comparable with the view provided by the traditional OM. Therefore, the combination of sensitive, accurate, precise and standardized FEC techniques, as the Mini-FLOTAC, with a reliable automated system, will permit the real-time observation and quantification of parasitic structures, thanks also to artificial intelligence software, that is under development. For these reasons, the KFM is a promising tool for an accurate and efficient FEC to improve parasite diagnosis and to assist new generations of operators in veterinary and public health.
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