{"title":"Intestinal helminths in farmed pacu (Piaractus mesopotamicus): Hematological and histopathological effects","authors":"E.O. Furlan , E.M. Belotti , D.M. Alvez , S.B. Chemes , P.M. Beldomenico","doi":"10.1016/j.vetpar.2025.110551","DOIUrl":"10.1016/j.vetpar.2025.110551","url":null,"abstract":"<div><div>Biosecurity in aquaculture is essential to reduce disease burden and ensure sustainability. <em>Piaractus mesopotamicus</em> (pacu) is a key species in South American aquaculture, yet parasitic threats to its health remain understudied. We analyzed intestinal helminth and assessed their effects on the health of 34 farmed pacu reared in intensive and semi-intensive systems in Santa Fe, Argentina, using parasitological, hematological, and histopathological approaches. Three parasite taxa were identified: the digenean <em>Dadaytrema oxycephala</em> (∼65 % prevalence; mean abundance: ∼3 parasites/fish), the nematode <em>Rondonia rondoni</em> (3 % prevalence; one host with 119 parasites), and the acanthocephalan <em>Echinorhynchus jucundus</em> (100 % prevalence; mean abundance: ∼235 parasites/fish). <em>E. jucundus</em> caused macrocytic hypochromic anemia (low erythrocyte count and hemoglobin, high MCV) and severe intestinal lesions (muscle penetration and chronic inflammation). <em>D. oxycephala</em> had marginal hematological effects. Infestations likely originated in land-based ponds, where zooplankton hosts thrive in the absence of technical biosecurity measures. Despite the high parasite burden, infected fish maintained stable body condition, suggesting a degree of physiological tolerance. However, the risk of nutrient malabsorption and market rejection remains. We propose: (1) prevention measures such as ≥ 15-day quarantine, pond sterilization, zooplankton monitoring in semi-intensive systems, water quality control in intensive systems, and necropsy of samples in cases of low feed conversion; (2) corrective action via targeted anthelmintic treatment or culling during outbreaks (>50 parasites/gut). This study identifies <em>E. jucundus</em> as an emerging pathogenic parasite and highlights the need for tailored biosecurity protocols adapted to different production systems, promoting the sustainable culture of pacu.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"338 ","pages":"Article 110551"},"PeriodicalIF":2.0,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144694678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pamella Pryscila de Alvarenga Bissoli Maciel de Lima , Patrícia Gonzaga Paulino , Nelson Meireles da Silva , Karina Cristina Paes Galdino , Carla Alves Rabello , Fernanda Gonçalves de Souza , Túlio Leite Reis , Leandro dos Santos Machado , Felipe Dilelis de Resende Souza , Huarrisson Azevedo Santos
{"title":"Dose and age-dependent effects of Eimeria spp. infection on cytokine and intestinal integrity gene expression in broiler chickens","authors":"Pamella Pryscila de Alvarenga Bissoli Maciel de Lima , Patrícia Gonzaga Paulino , Nelson Meireles da Silva , Karina Cristina Paes Galdino , Carla Alves Rabello , Fernanda Gonçalves de Souza , Túlio Leite Reis , Leandro dos Santos Machado , Felipe Dilelis de Resende Souza , Huarrisson Azevedo Santos","doi":"10.1016/j.vetpar.2025.110550","DOIUrl":"10.1016/j.vetpar.2025.110550","url":null,"abstract":"<div><div>The aim of this study was to evaluate the effects of <em>Eimeria</em> spp. challenge dose and age on gene expression of pro- and anti-inflammatory cytokines and intestinal integrity markers in broiler chickens. One-day-old chicks were orally challenged with a commercial vaccine at doses of 10 × (G1) and 40 × (G2) higher than those recommended by the manufacturer, whereas the control group (GC) received PBS. Broiler chickens were euthanized at 7, 14, and 21 days post-infection (dpi) for cecal tissue collection. The results revealed early intestinal barrier disruption at 7 dpi, particularly in G2, when tight junction genes (<em>ZO-A</em>, <em>claudin-C</em>, and <em>JAM</em>) were significantly downregulated. By 14 dpi, <em>occludin</em> gene expression had increased in G2, suggesting a compensatory attempt to restore gut integrity. The immune response followed a distinct pattern depending on dose and age. At 14 dpi, the pro-inflammatory cytokines <em>IL1β</em>, <em>IL2</em>, and <em>IFN-γ</em> peaked in both groups, although the response was stronger in G1, indicating more controlled activation. However, by 21 dpi, G2 showed marked suppression of <em>IL10</em> and <em>IFN-γ</em>. In contrast, <em>CD8</em> expression was strongly upregulated in G2 at 21 dpi, indicating a delayed but heightened cytotoxic response. Interestingly, despite shifts in cytokine expression, intestinal integrity markers showed only limited changes over time, suggesting that the immune response was more affected by parasite load than by structural damage to the gut. These findings highlight how dose and age shape the host response to <em>Eimeria</em> spp., and emphasize the importance of tailored coccidiosis management strategies in poultry production.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"338 ","pages":"Article 110550"},"PeriodicalIF":2.0,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144711955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tugce Antepli̇oglu , Merve Bi̇ski̇n Turkmen , Naci Ocal , Erva Eser , Gizem Imrak , Oguz Kul
{"title":"Dopaminergic neuropathology in calves naturally infected with Neospora caninum","authors":"Tugce Antepli̇oglu , Merve Bi̇ski̇n Turkmen , Naci Ocal , Erva Eser , Gizem Imrak , Oguz Kul","doi":"10.1016/j.vetpar.2025.110548","DOIUrl":"10.1016/j.vetpar.2025.110548","url":null,"abstract":"<div><div><em>Neospora caninum</em> is a protozoan parasite that causes abortion and congenital neurological disorders in cattle. Although its reproductive effects are well established, the neurochemical alterations associated with congenital infections remain unclear. This study aimed to evaluate the spatial relationship between <em>N. caninum</em> antigen distribution and the expression of dopaminergic markers in the brains of naturally infected neonatal calves. Brain tissues from infected and healthy calves were examined histopathologically and immunohistochemically. Immunohistochemistry was performed using antibodies against <em>N. caninum</em>, tyrosine hydroxylase (TH), dopamine receptor D1 (DRD1), and dopamine transporter (DAT). Regional immunoreactivity was semi-quantitatively assessed and compared between groups. Antigen positivity was observed only in infected calves, mainly within neuronal cytoplasm, and was most prominent in the forebrain and cerebral cortex. TH expression was markedly increased in these regions, while DRD1 and DAT expression was moderately reduced or regionally altered. Tissue cysts were absent except in one case. These findings indicate a region-specific dopaminergic imbalance associated with parasitic localization. This pattern is similar to previously described changes in <em>Toxoplasma gondii</em> models and suggests that <em>N. caninum</em> may also impair dopaminergic regulation in the developing brain. Further behavioral and molecular studies are warranted to explore the neurochemical consequences of congenital neosporosis.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"338 ","pages":"Article 110548"},"PeriodicalIF":2.0,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Camila Vázquez-Cañás , María S. Gaspe , Gustavo F. Enriquez , Daniel D. Sánchez , Delfina Trezza-Neumayer , Bárbara L. Ojeda , Santiago Piñero , Claudia V. Vassena , Marta V. Cardinal
{"title":"Spot-on application of fluralaner on cats produces high mortality in pyrethroid-resistant and susceptible Triatoma infestans, in comparison with spinosad and imidacloprid","authors":"Camila Vázquez-Cañás , María S. Gaspe , Gustavo F. Enriquez , Daniel D. Sánchez , Delfina Trezza-Neumayer , Bárbara L. Ojeda , Santiago Piñero , Claudia V. Vassena , Marta V. Cardinal","doi":"10.1016/j.vetpar.2025.110547","DOIUrl":"10.1016/j.vetpar.2025.110547","url":null,"abstract":"<div><div>Pyrethroid resistance is an increasing threat to vector control programs worldwide. Triatomines, the vectors of Chagas disease are also exhibiting resistant phenotypes. In the Gran Chaco region the increasing emergence of pyrethroid-resistant <em>Triatoma infestans</em> populations calls for renewed efforts in search of alternative tools that could complement traditional vector control activities based on insecticide spraying. With this intention, we evaluated the efficacy of three commercially available ectoparasiticides for veterinarian use in cats: fluralaner (Bravecto<em>®</em>), imidacloprid (Power Met<em>®</em>) and spinosad (Power<em>®</em>), on the mortality of pyrethroid-resistant and -susceptible <em>T. infestans</em>. The trial included 25 domestic, owned cats, randomly assigned to one of the three treatments or two control groups. Bioassays were performed at 0, 4, 30 and 60 days post-treatment (DPT) and consisted in exposing groups of laboratory-reared third to fifth-instar nymphs to each cat. Kaplan-Meier curves showed a significant reduction of survival probability in the triatomines exposed to cats treated with fluralaner and spinosad comparing with their respective controls whereas no lethal effects were observed in the imidacloprid-treated group. In fluralaner-treated cats, triatomines exhibited 80 %, 54 % and 29 % of mortality at 4, 30 and 60 DPT, respectively; whereas in spinosad-treated cats, triatomines achieved 56 % and 37 % of mortality at 4 and 30 DPT, respectively. No significant effect of triatomines pyrethroid-susceptibility status was observed. Given the higher mortality levels achieved and longer lethal effect, our results support the evaluation of cat treatment with fluralaner in a Phase II trial to cope with current challenges of vector control like pyrethroid-resistance.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"338 ","pages":"Article 110547"},"PeriodicalIF":2.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144656688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Simone Morelli , Angela Di Cesare , Donato Traversa , Chiara Astuti , Ilaria Lallone , Costantina N. Tsokana , Donatella Damiani , Melissa Beall , Jesse Buch , Daniela do Amaral Grossi , Sarah Peterson , Gaia Grimaldi , Clarissa Damiani , Barbara Paoletti , Anastasia Diakou
{"title":"Occurrence of Cystoisospora spp. and other intestinal parasites in dogs and cats with diarrhea","authors":"Simone Morelli , Angela Di Cesare , Donato Traversa , Chiara Astuti , Ilaria Lallone , Costantina N. Tsokana , Donatella Damiani , Melissa Beall , Jesse Buch , Daniela do Amaral Grossi , Sarah Peterson , Gaia Grimaldi , Clarissa Damiani , Barbara Paoletti , Anastasia Diakou","doi":"10.1016/j.vetpar.2025.110546","DOIUrl":"10.1016/j.vetpar.2025.110546","url":null,"abstract":"<div><div>The occurrence of <em>Cystoisospora</em> spp. and other intestinal parasites in young dogs (n. 117) and cats (n. 118) with diarrhea was evaluated. Fecal samples were processed using flotation and sucrose concentration, and fecal and clinical scores were assigned to each animal. Statistical associations between the occurrence of coccidia and/or other intestinal parasites and the severity of clinical signs were evaluated. Seven dogs were infected only with <em>Cystoisospora canis</em> (6.8 %), 3 only with <em>Cystoisospora ohioensis</em>-like (3.4 %) and 1 with both (0.9 %). Forty cats (33.9 %) tested positive for coccidia, i.e. 33 (28 %) only with <em>Cystoisospora felis</em>, 6 (5.1 %) only with <em>Cystoisospora rivolta</em>, and 1 (0.8 %) with both. Other parasites recorded were <em>Giardia</em> spp., Ancylostomatidae, <em>Toxocara</em> spp. and Taeniidae. All dogs with coccidiosis had very soft feces. Watery/hemorrhagic diarrhea was detected in 4/21 (19 %) and 2/5 (40 %) cats infected with <em>C. felis</em> and <em>C. rivolta</em>, respectively. The occurrence of coccidia and <em>Toxocara</em>, and of hookworms and <em>Giardia,</em> was significantly higher (p ≤ 0.05) in cats than in dogs, and <em>vice versa</em>. Other significant associations found in dogs were: reduced activity and positivity to <em>C. canis</em>, presence of very soft feces and positivity to Ancylostomatidae. In cats, the positivity to Ancylostomatidae was significantly correlated with vomiting, dehydration, watery/hemorrhagic diarrhea. This study highlights the frequent occurrence of <em>Cystoisospora</em> spp. in young dogs and cats with diarrhea, with a higher incidence in cats compared to dogs. The clinical score results suggested a more pathogenic role of <em>C. canis</em> and <em>C. rivolta</em> in dogs and cats, respectively.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"338 ","pages":"Article 110546"},"PeriodicalIF":2.0,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144670615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Roger I. Rodríguez–Vivas , Gabriela J. Flota–Burgos , José A. Rosado–Aguilar , Edwin J. Gutiérrez–Ruiz , Iris Trinidad–Martínez , Vanesa Evia–Pech , Gustavo Vázquez
{"title":"Effectiveness of oral ivermectin, praziquantel, and fenbendazole against intestinal helminths in fighting birds","authors":"Roger I. Rodríguez–Vivas , Gabriela J. Flota–Burgos , José A. Rosado–Aguilar , Edwin J. Gutiérrez–Ruiz , Iris Trinidad–Martínez , Vanesa Evia–Pech , Gustavo Vázquez","doi":"10.1016/j.vetpar.2025.110545","DOIUrl":"10.1016/j.vetpar.2025.110545","url":null,"abstract":"<div><div>The study's objective was to evaluate the <em>in vivo</em> effectiveness of the combination of ivermectin + praziquantel + fenbendazole (I+P+F) against intestinal nematodes and cestodes in fighting birds. Fecal samples were taken from 181 birds to estimate the frequency of intestinal helminths. For the evaluation of anthelmintic efficacy, the birds were randomly distributed into four groups (10–19 birds/group) according to the anthelmintic evaluated: ivermectin (0.4 mg/kg orally), praziquantel (10 mg/kg orally), fenbendazole (16 mg/kg orally), and the combination of I+P+F (ivermectin 0.4 mg/kg + praziquantel 10 mg/kg + fenbendazole 16 mg/kg, orally). The effectiveness of the treatments was measured on days 0, 7, 14, and 21 post–treatments (PT). Faecal samples were taken and analyzed using Centrifugal Flotation and McMaster techniques. Overall, 33.7 % (61/181) of the birds were positive for intestinal helminths, these being <em>Heterakis</em> spp. (68.8 %), <em>Capillaria</em> spp. (55.7 %), and <em>Raillietina</em> spp. (54.0 %). The ivermectin and fenbendazole groups showed efficacy of 86–100 % and 66–100 %, against nematodes, respectively. The praziquantel group presented 90–100 % effectiveness for controlling <em>Raillietina</em> spp. The combination of I+P+F showed anthelmintic efficacy (100 %) from seven to 21 days PT against <em>Heterakis</em> spp., <em>Capillaria</em> spp., and <em>Raillietina</em> spp. This formulation was more effective than the individual administration of the evaluated anthelmintics in naturally infected fighting birds.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"338 ","pages":"Article 110545"},"PeriodicalIF":2.0,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144656689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thayany Magalhães de Almeida , Felipe de Oliveira , Samanta Cristina das Chagas Xavier , Pilar Alda , Marcelo Beltrão Molento
{"title":"Ecological niche and distribution patterns of snails that host Fasciola hepatica across South America: Unveiling the hidden landscapes","authors":"Thayany Magalhães de Almeida , Felipe de Oliveira , Samanta Cristina das Chagas Xavier , Pilar Alda , Marcelo Beltrão Molento","doi":"10.1016/j.vetpar.2025.110541","DOIUrl":"10.1016/j.vetpar.2025.110541","url":null,"abstract":"<div><div>In South America, <em>Pseudosuccinea columella</em>, <em>Galba cubensis</em>, <em>Galba schirazensis</em>, and <em>Galba truncatula</em> snails serve as vectors of <em>Fasciola hepatica</em>, posing significant challenges to public and animal health. This study identified environmentally suitable areas for these species using ecological niche models, including Maxent, Random Forest, and Support Vector Machine (SVM) models. Occurrence points (n = 797) were compiled from the international literature, following the PRISMA protocol, and the malacological collection of the FIOCRUZ Institute in Rio de Janeiro, Brazil. <em>P. columella</em> (51 %) and <em>G. truncatula</em> (18 %) had the highest records. The distribution of <em>Pseudosuccinea columella</em> and <em>G. cubensis</em> was influenced by precipitation, exhibiting a broad potential across South America. In contrast, the distribution of <em>G. schirazensis</em> and <em>G. truncatula</em> was influenced by temperature and was limited to high-altitude areas. An ecological niche overlap was observed between <em>P. columella</em> and <em>G. cubensis</em> and <em>G. schirazensis</em> and <em>G. truncatula</em>. Moreover, suitable areas for these species were identified in Argentina, Peru, Bolivia, and Brazil. In Brazil, <em>P. columella</em> has demonstrated significant environmental suitability in the Cerrado and Amazon Forest biomes, which have been impacted by land-use changes, including pasture expansion and deforestation resulting from unsupervised cattle production. Therefore, predicting the contamination of new areas is critical to mitigate future liver fluke infections in suitable hosts (natives and rural communities, capybaras, etc.) from regions affected by large livestock movements on the continent. As we face climate change threats to vector-borne diseases, these modeling data highlight the need for significant preventive strategies aimed at the welfare and social impact of all South American countries.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"338 ","pages":"Article 110541"},"PeriodicalIF":2.0,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144595806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Characterization of cyclophilin 23 as a novel factor for development and pathogenicity of Cryptosporidium parvum","authors":"Mengfei Xu, Xichen Zhang, Qile Yu, Qi Zhao, Jianhua Li, Pengtao Gong, Xiaocen Wang, Xin Li, Xu Zhang, Nan Zhang","doi":"10.1016/j.vetpar.2025.110539","DOIUrl":"10.1016/j.vetpar.2025.110539","url":null,"abstract":"<div><div><em>Cryptosporidium parvum</em> (<em>C. parvum</em>) is a common zoonotic protozoan pathogen that can cause severe diarrhea in both humans and animals. However, the factors involved in its pathogenicity remain incompletely understood. The <em>C. parvum</em> genome contains nine genes that encode peptidyl-prolyl cis/trans isomerases (PPIases). Previous bioinformatics analyses have indicated that proteins within this family may be associated with the pathogenicity of <em>C. parvum</em>. Here, we explored the role of cyclophilin 23 (CpCyP23), a member of the PPIase family, in the development and pathogenicity of <em>C. parvum</em>. In this study, the <em>CpCyP23</em> gene was tagged and deleted using CRISPR/Cas9 technology in <em>C. parvum</em>. Immunofluorescence analysis demonstrated that CpCyP23 is expressed in all key developmental stages of <em>C. parvum.</em> The impact of <em>CpCyP23</em> deficiency on parasite development and pathogenicity were assessed in HCT-8 cells and interferon-γ knockout mice, and the results revealed that the lack of <em>CpCyP23</em> delayed the development of <em>C. parvum</em> in vitro. Moreover, compared with mice inoculated with the tagged strain, those infected with the knockout strain exhibited a reduction in parasite burden and small intestinal damage. These findings demonstrate that CpCyP23 plays a role in the development of <em>C. parvum</em>, and the deletion of the <em>CpCyP23</em> gene reduces the pathogenicity of the <em>C. parvum</em>. Overall, these results advance our understanding of the pathogenic mechanisms of <em>C. parvum</em> and suggest CpCyP23 is a promising target for intervention in cryptosporidiosis.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"338 ","pages":"Article 110539"},"PeriodicalIF":2.0,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144604935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Deliah Tamsyn Winterfeld , Birgit Schauer , Majda Globokar , Nikola Pantchev , Susan Mouchantat , Franz Josef Conraths , Helge Kampen , Gereon Schares , Pavlo Maksimov , Jana Schulz
{"title":"Evaluation of established and new methods for the detection of Toxocara spp. in cats and dogs without a gold standard – A Bayesian latent class analysis","authors":"Deliah Tamsyn Winterfeld , Birgit Schauer , Majda Globokar , Nikola Pantchev , Susan Mouchantat , Franz Josef Conraths , Helge Kampen , Gereon Schares , Pavlo Maksimov , Jana Schulz","doi":"10.1016/j.vetpar.2025.110544","DOIUrl":"10.1016/j.vetpar.2025.110544","url":null,"abstract":"<div><div>The commonly used detection method for <em>Toxocara canis</em> and <em>Toxocara cati</em> eggs in faecal samples is the sedimentation-flotation technique (SF). Based on this method, a sequential sieving protocol (SF-SSV) was developed to achieve a higher sensitivity in detecting <em>Toxocara</em> spp. eggs. In addition, two automated DNA extraction methods for faecal samples were applied. Faecal samples of cats (n = 125) and dogs (n = 175) were tested to detect <em>Toxocara</em> spp. with all four methods. Two populations were investigated; one was considered positive based on previous examinations (n = 120), and the other one represented a field population-based sample (n = 180). In general, the parasitological methods (SF, SF-SSV) had in all cases higher estimated sensitivities than the DNA detection methods. For both, cats and dogs, the SF-SSV had significantly higher sensitivities than the DNA detection methods. The estimates for specificity were above 90 % in each analysis, but lowest for the SF-SSV. By DNA detection, <em>T. cati</em>-specific methods tended to have higher diagnostic sensitivities than <em>T. canis</em>-specific methods, but not statistically significant. Traditional methods of evaluating diagnostic tests require a gold standard and a pool of appropriate reference samples. Since there is no gold standard for detecting <em>Toxocara</em> spp. in cats and dogs, Bayesian Latent Class Analysis (BLCA), a probabilistic approach estimating test performance, is a useful tool to estimate sensitivity and specificity based on the available data. This study highlights the challenge of obtaining suitable samples for model estimation, especially in field settings where <em>Toxocara</em> spp. prevalence is typically very low.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"338 ","pages":"Article 110544"},"PeriodicalIF":2.0,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144587684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}