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In adult cattle Fasciola hepatica infection usually follows a chronic subclinical course, and reduces both the milk yield and milk quality, resulting in considerable financial losses. Effective control of the disease is based on reliable identification of asymptomatically infected individuals, which now requires special parasitological or serological diagnostic tests. It is also known that F. hepatica infection induces alterations in some serum biochemical parameters. Therefore, the study was conducted to develop a model based on serum biochemical parameters allowing to identify cows at higher risk of chronic fascioliasis. Six hundred sixty eight adult dairy cows from 97 herds located in central and northeastern Poland were clinically examined, and blood and fecal samples from them were collected for a routine monitoring of fascioliasis and metabolic profile. Using the combination of fecal sedimentation test and indirect ELISA based on excretory/secretory products 203 cows, apparently healthy in clinical examination, were definitively classed as affected by (47 cows, 23.2%) or free from (156 cows, 76.8%) chronic fascioliasis. Their serum was screened for the activity of 4 enzymes (γ-glutamyl transpeptidase, glutamate dehydrogenase, aspartate aminotransferase, creatine kinase) and concentration of 18 other components (total bilirubin, total protein, albumin, globulin, urea, glucose, non-esterified fatty acids, β-hydroxybutyrate, sodium, potassium, chloride, calcium, magnesium, copper, zinc, iron, selenium, and haptoglobin). Logistic regression analysis was used to build 4 multivariable models allowing for identification of cows at risk of chronic fascioliasis. Then, the accuracy was compared between the models using the area under the receiver operating characteristic curve (AUROC), and an optimal cut-off value was determined for the most accurate model using Youden J index. The most accurate proved to be the model based on glutamate dehydrogenase activity and globulin, urea (all three positively linked with risk of chronic fascioliasis), and selenium concentration (negatively linked) adjusted by the access to pasture and cow's age. At the optimal cut-off of 0.37 this model had sensitivity of 85.1% (CI 95%:72.3%, 92.6%), specificity of 90.4% (CI 95%:84.7%, 94.1%), positive likelihood ratio of 8.8 (CI 95%:5.4, 14.5), and negative likelihood ratio of 0.16 (CI 95%:0.08, 0.33). This model performed significantly better than model including only γ-glutamyl transpeptidase or model including both γ-glutamyl transpeptidase and aspartate aminotransferase (both also adjusted by the access to pasture and cow's age), and was the only model which performed significantly better than the basic model based solely on the access to pasture and cow's age., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Fasciola hepatica and Ostertagia ostertagi infections are widespread in cattle population of Europe, however data on their prevalence in Poland are only fragmentary. Therefore, the cross-sectional study was carried out to determine the herd-level seroprevalence of F. hepatica and O. ostertagi infection in dairy cattle population in the central and north-eastern provinces Poland, and to identify basic local risk factors for these infections. In total, 598 herds were enrolled, 394 (65.9%) in the north-eastern province and 204 (34.1%) in the central province. In each herd the questionnaire survey was conducted and bulk-tank milk (BTM) sample was collected and screened using two indirect immunoenzymatic tests. Optical density ratio (ODR) was regarded as the quantitative proxy of exposure to either of the two parasites., Results: Both Fasciola and Ostertagia ELISA ODR in the north-eastern province was significantly higher than ODR in the central province. At the cut-off value of ODR = 0.27 the true herd-level seroprevalence of F. hepatica was 79.6% (95% CI: 74.0%, 84.3%) in the north-eastern province and 13.0% (95% CI: 5.3%, 21.7%) in the central province. At the cut-off of ODR = 0.50151 of 188 herds (80.3%, 95% CI: 74.1%, 85.4%) were seropositive for O. ostertagi in the north-eastern province and only 70 of 136 herds (51.5%, 95% CI: 43.1%, 59.7%) were seropositive in the central province. Location of a herd in the north-eastern province, longer grazing period practiced in a herd and > 50%-share of grazing grass in roughage were all positively related to the increase in exposure to both parasites. Moreover, the use of hay or haylage as main roughage proved to be positively related to the increase in exposure to F. hepatica., Conclusions: F. hepatica and O. ostertagi are widespread in cattle population in Poland, however their occurrence at a herd-level varies between different regions of Poland. This diversity can only partly be explained by different herd management, and appears linked to environmental and climate conditions typical for these regions.

A serosurvey was carried out to estimate the herd-level seroprevalence of Neospora caninum infection in cattle in central and northeastern Poland. Ninety seven dairy cattle herds from 2 provinces of Poland (Podlaskie, 47 herds and Łodzkie, 50 herds) were randomly enrolled in the study using two-stage cluster method. A simple random selection was applied within each herd to select a sample of adult cows (≥18 month-old). A total number of 734 cows were enrolled in the study. The animals were screened with a commercial competitive ELISA (Bio-X Diagnostics, Belgium). To calculate true herd-level seroprevalence test sensitivity and specificity were adjusted from an individual- to a herd-level using FreeCalc method. The true overall herd-level seroprevalence of N. caninum infection was 56.7% (95% CI: 47.5%, 65.9%). The true herd-level seroprevalence in Podlaskie was 63.3% (95% CI: 43.0%, 83.6%) and 50.5% (95% CI: 32.8%, 68.2%) in Łodzkie province and these figures did not differ significantly between the two provinces (chi2 test p = 0.238). One hundred forty three of 734 cows (19.5%) were seropositive which gave the true overall individual-level seroprevalence of 20.1% (95% CI: 17.4%, 23.2%). Percentage of seropositive cows in each herd varied from 6% to 80%. This study is the first epidemiological investigation of herd-level seroprevalence of N. caninum infection in Polish dairy cattle population. In conclusion, the result of the study confirmed previous data that N. caninum infection is widespread in the Polish cattle population and thus should be considered as a potential cause of spontaneous abortions.

Background: A major constraint for the effective control and management of helminth parasites is the lack of rapid, high-throughput, routine diagnostic tests to assess the health status of individual animals and herds and to identify the parasite species responsible for these helminthoses. The capability of a multiplex platform for the simultaneous detection of three pasture associated parasite species was evaluated and compared to existing ELISAs., Methods: The recombinant antigens 14.2 kDa ES protein for Cooperia oncophora, major sperm protein for Dictyocaulus viviparus and Cathepsin L1 for Fasciola hepatica were recombinantly expressed either in Escherichia coli or Pichia pastoris. Antigens were covalently coupled onto magnetic beads. Optimal concentrations for coupling were determined following the examination of serum samples collected from experimentally mono-infected animals, before and after their infection with the target species. Absence of cross-reactivity was further determined with sera from calves mono-infected with Haemonchus contortus, Ostertagia ostertagi and Trichostrongylus colubriformis. Examination of negative serum samples was characterised by low median fluorescence intensity (MFI)., Results: Establishment of the optimal serum dilution of 1:200 was achieved for all three bead sets. Receiver Operating Characteristic analyses were performed to obtain cut-off MFI values for each parasite separately. Sensitivity and specificity at the chosen cut-off values were close to, or 100% for all bead sets. Examination of serum samples collected on different days post infection from different animals showed a high reproducibility of the assays. Serum samples were additionally examined with two already established ELISAs, an in-house ELISA using the recombinant MSP as an antigen and a DRG ELISA using Cathepsin L1 for liver fluke. The results between the assays were compared and kappa tests revealed an overall good agreement., Conclusions: A versatile bead-based assay using fluorescence detection (xMAP technology) was developed to simultaneously detect antibodies against C. oncophora, D. viviparus and F. hepatica in cattle serum samples. This platform provides rapid, high-throughput results and is highly sensitive and specific in comparison to existing serological as well as coproscopical diagnostic techniques.