scholarly journals Modelling the spatial distribution of Fasciola hepatica in dairy cattle in Europe

2015 ◽  
Vol 9 (2) ◽  
pp. 261 ◽  
Author(s):  
Els Ducheyne ◽  
Johannes Charlier ◽  
Jozef Vercruysse ◽  
Laura Rinaldi ◽  
Annibale Biggeri ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Dairy Cattle ◽  
Fasciola Hepatica ◽  
Current Knowledge ◽  
Density Ratio ◽  
Sampling Strategy ◽  
Boosted Regression Trees ◽  
Enzyme Linked Immunosorbent Assay ◽  
Temporal Models ◽  
Optical Density Ratio

A harmonized sampling approach in combination with spatial modelling is required to update current knowledge of fasciolosis in dairy cattle in Europe. Within the scope of the EU project GLOWORM, samples from 3,359 randomly selected farms in 849 municipalities in Belgium, Germany, Ireland, Poland and Sweden were collected and their infection status assessed using an indirect bulk tank milk (BTM) enzyme-linked immunosorbent assay (ELISA). Dairy farms were considered exposed when the optical density ratio (ODR) exceeded the 0.3 cut-off. Two ensemble-modelling techniques, Random Forests (RF) and Boosted Regression Trees (BRT), were used to obtain the spatial distribution of the probability of exposure to <em>Fasciola hepatica</em> using remotely sensed environmental variables (1-km spatial resolution) and interpolated values from meteorological stations as predictors. The median ODRs amounted to 0.31, 0.12, 0.54, 0.25 and 0.44 for Belgium, Germany, Ireland, Poland and southern Sweden, respectively. Using the 0.3 threshold, 571 municipalities were categorized as positive and 429 as negative. RF was seen as capable of predicting the spatial distribution of exposure with an area under the receiver operation characteristic (ROC) curve (AUC) of 0.83 (0.96 for BRT). Both models identified rainfall and temperature as the most important factors for probability of exposure. Areas of high and low exposure were identified by both models, with BRT better at discriminating between low-probability and high-probability exposure; this model may therefore be more useful in practise. Given a harmonized sampling strategy, it should be possible to generate robust spatial models for fasciolosis in dairy cattle in Europe to be used as input for temporal models and for the detection of deviations in baseline probability. Further research is required for model output in areas outside the eco-climatic range investigated.

Bulk tank milk ELISA to detect IgG1 prevalence and clustering to determine spatial distribution and risk factors of Fasciola hepatica-infected herds in Mexico

2018 ◽  
Vol 93 (6) ◽  
pp. 704-710 ◽  
Author(s):  
A. Villa-Mancera ◽  
A. Reynoso-Palomar
Keyword(s):  
Spatial Distribution ◽  
Fasciola Hepatica ◽  
Density Ratio ◽  
Control Measures ◽  
Economic Losses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Bulk Tank Milk ◽  
Optical Density Ratio ◽  
Bulk Tank ◽  
Cattle Herds

AbstractFasciola hepatica is a helminth parasite that causes huge economic losses to the livestock industry worldwide. Fasciolosis is an emerging foodborne zoonotic disease that affects both humans and grazing animals. This study investigated the associations between climatic/environmental factors (derived from satellite data) and management factors affecting the spatial distribution of this liver fluke in cattle herds across different climate zones in three Mexican states. A bulk-tank milk (BTM) IgG1 enzyme-linked immunosorbent assay (ELISA) test was used to detect F. hepatica infection levels of 717 cattle herds between January and April 2015. Management data were collected from the farms by questionnaire. The parasite's overall herd prevalence and mean optical density ratio (ODR) were 62.76% and 0.67, respectively. The presence of clustered F. hepatica infections was studied using the spatial scan statistic. Three marked clusters in the spatial distribution of the parasite were observed. Logistic regression was used to test three models of potential statistical association from the ELISA results using climatic, environmental and management variables. The final model based on climatic/environmental and management variables included the following factors: rainfall, elevation, proportion of grazed grass in the diet, contact with other herds, herd size, parasite control use and education level as significant predictors. Geostatistical kriging was applied to generate a risk map for the presence of parasites in dairy herds in Mexico. In conclusion, the spatial distribution of F. hepatica in Mexican cattle herds is influenced by multifactorial effects and should be considered in developing regionally adapted control measures.

Anaphylactic Reactions to Aprotinin Reexposure in Cardiac Surgery

2001 ◽  
Vol 95 (1) ◽  
pp. 64-71 ◽  
Author(s):  
Wulf Dietrich ◽  
Paul Späth ◽  
Michael Zühlsdorf ◽  
Harald Dalichau ◽  
Paul G. Kirchhoff ◽  
...  
Keyword(s):  
Cardiac Surgery ◽  
Confidence Interval ◽  
Anaphylactic Reaction ◽  
Optical Density ◽  
Density Ratio ◽  
Quantitative Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Ige Antibodies ◽  
Optical Density Ratio ◽  
Antigenic Properties

Background Aprotinin, a serine proteinase inhibitor, reduces bleeding during cardiac surgery. As aprotinin is derived from bovine lung, it has antigenic properties. This investigation examined the incidence of anaphylactic reactions in patients reexposed to aprotinin and the relation to preformed antiaprotinin immunoglobulin (Ig)G and IgE antibodies. Methods This prospective observational study conducted at five centers in Germany evaluated patients undergoing repeat cardiac surgery reexposed to aprotinin between 1995 and 1996. Antiaprotinin IgG and IgE antibody measurements, using a noncommercial enzyme-linked immunosorbent assay and an immunofluorescence assay, respectively, were performed preoperatively and postoperatively. An anaphylactic reaction was defined as major changes from baseline within 10 min of aprotinin administration of systolic pressure 20% or greater, heart rate 20% or greater, inspiratory pressure greater than 5 cm H2O, or a skin reaction. Results In 121 cases (71 adults, 46 children), a mean aprotinin reexposure interval of 1,654 days (range, 16-7,136 days) was observed. Preoperative antiaprotinin IgG (optical density ratio &gt; 3) and IgE antibodies (radioallergosorbent test [RAST] score &lt; 3) were detected in 18 and 9 patients, respectively. High concentrations of each (IgG, optical density ratio &gt; 10; IgE, RAST score &gt; or = 3) were detected in five patients. Three patients (2.5%; 95% confidence interval, 0.51-7.1%) experienced an anaphylactic reaction after aprotinin exposure, followed by full recovery; these patients had reexposure intervals less than 6 months (22, 25, and 25 days) and the highest preoperative IgG concentrations of all patients (P &lt; 0.05). Assay sensitivity was 100%, as no anaphylactic reactions occurred in IgG-negative patients (95% confidence interval, 0.0-3.1%); assay specificity was 98%. Preoperative IgE measurements were quantifiable in two of three reactive patients and in three nonreacting patients. Conclusions Quantitative detection of antiaprotinin IgE and IgG lacks specificity for predictive purposes; however, quantitation of antiaprotinin IgG may identify patients at risk for developing an anaphylactic reaction to aprotinin reexposure.

scholarly journals Antibody Responses to SARS-CoV-2 in Coronavirus Diseases 2019 Patients with Different Severity

2020 ◽  
Author(s):  
Ekasit Kowitdamrong ◽  
Thanyawee Puthanakit ◽  
Watsamon Jantarabenjakul ◽  
Eakachai Prompetchara ◽  
Pintip Suchartlikitwong ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Respiratory Infections ◽  
Density Ratio ◽  
Clinical Manifestations ◽  
High Sensitivity ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serological Response ◽  
Optical Density Ratio ◽  
Severe Group

Background: More understanding of antibody responses in the SARS-CoV-2 infected population is useful for vaccine development. Aim: To investigate SARS-CoV-2 IgA and IgG among COVID-19 Thai patients with different severity. Methods: We used plasma from 118 adult patients who have confirmed SARS-CoV-2 infection and 49 patients under investigation without infection, 20 patients with other respiratory infections, and 102 healthy controls. Anti-SARS-CoV-2 IgA and IgG were performed by enzyme-linked immunosorbent assay from Euroimmun. The optical density ratio cut off for positive test was 1.1 for IgA and 0.8 for IgG. The association of antibody response with the severity of diseases and the day of symptoms was performed. Results: From Mar 10 to May 31, 2020, 289 participants were enrolled, and 384 samples were analyzed. Patients were categorized by clinical manifestations to mild (n=59), moderate (n=27) and severe (n=32). The overall sensitivity of IgA and IgG from samples collected after day 7 is 87.9% (95% CI 79.8-93.6) and 84.8% (95% CI 76.2-91.3), respectively. The severe group had a significantly higher level of specific IgA and IgG to S1 antigen compared to the mild group. All moderate to severe patients have specific IgG while 20% of the mild group did not have any IgG detected after two weeks. Interestingly, SARS-CoV-2 IgG level was significantly higher in males compared to females among the severe group (p=0.003). Conclusion: The serologic test for SARS-CoV-2 has high sensitivity after the second week after onset of illness. Serological response differs among patients with different severity and different sex.

scholarly journals Absence of Immunogenicity of Diaspirin Cross-Linked Hemoglobin in Humans

Blood ◽  
1998 ◽  
Vol 91 (2) ◽  
pp. 710-716 ◽  
Author(s):  
Mehul J. Patel ◽  
Edwin J. Webb ◽  
Tina E. Shelbourn ◽  
Cynthia Mattia-Goldberg ◽  
Andrew J.T. George ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Western Blot ◽  
Optical Density ◽  
Oxygen Carrier ◽  
Density Ratio ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Western Blot Assay ◽  
Patient Sample ◽  
Optical Density Ratio

Abstract Diaspirin cross-linked hemoglobin (DCLHb) is an intramolecularly cross-linked hemoglobin-based oxygen carrier being developed as a therapy for acute blood loss. We report here the absence of immunogenicity of DCLHb in patients enrolled in phase II and III clinical trials of DCLHb. Two very sensitive immunoassays, an enzyme-linked immunosorbent assay (ELISA) and a Western blot assay, were developed and validated for this assessment. The DCLHb-antibodies used in these assays were raised in monkeys, had similar affinities for DCLHb and native human hemoglobin (SFHb), and showed cross-reactivity for subunits of DCLHb and SFHb on the Western blot, suggesting that these antibodies were elicited as a xenogenic response to the protein. In the ELISA, the optical density of a patient sample exposed to DCLHb-coated wells was compared with that of the patient sample exposed to carbonate buffer-coated wells; an optical density ratio of 1.4 was established for discriminating between a positive (reactive) or negative DCLHb antibody response. To date, all of the more than 300 patient specimens (preinfusion and postinfusion) from clinical trials have exhibited a ratio of less than 1.4, confirming the lack of preexisting antibodies to DCLHb and clearly showing the absence of DCLHb antibodies after exposure to this new biologic entity. There has been no requirement for use of the confirmatory Western blot assay. Taken together, the results from this study indicate DCLHb is not immunogenic in humans at doses evaluated clinically.

scholarly journals Absence of Immunogenicity of Diaspirin Cross-Linked Hemoglobin in Humans

Blood ◽  
1998 ◽  
Vol 91 (2) ◽  
pp. 710-716
Author(s):  
Mehul J. Patel ◽  
Edwin J. Webb ◽  
Tina E. Shelbourn ◽  
Cynthia Mattia-Goldberg ◽  
Andrew J.T. George ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Western Blot ◽  
Optical Density ◽  
Oxygen Carrier ◽  
Density Ratio ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Western Blot Assay ◽  
Patient Sample ◽  
Optical Density Ratio

Diaspirin cross-linked hemoglobin (DCLHb) is an intramolecularly cross-linked hemoglobin-based oxygen carrier being developed as a therapy for acute blood loss. We report here the absence of immunogenicity of DCLHb in patients enrolled in phase II and III clinical trials of DCLHb. Two very sensitive immunoassays, an enzyme-linked immunosorbent assay (ELISA) and a Western blot assay, were developed and validated for this assessment. The DCLHb-antibodies used in these assays were raised in monkeys, had similar affinities for DCLHb and native human hemoglobin (SFHb), and showed cross-reactivity for subunits of DCLHb and SFHb on the Western blot, suggesting that these antibodies were elicited as a xenogenic response to the protein. In the ELISA, the optical density of a patient sample exposed to DCLHb-coated wells was compared with that of the patient sample exposed to carbonate buffer-coated wells; an optical density ratio of 1.4 was established for discriminating between a positive (reactive) or negative DCLHb antibody response. To date, all of the more than 300 patient specimens (preinfusion and postinfusion) from clinical trials have exhibited a ratio of less than 1.4, confirming the lack of preexisting antibodies to DCLHb and clearly showing the absence of DCLHb antibodies after exposure to this new biologic entity. There has been no requirement for use of the confirmatory Western blot assay. Taken together, the results from this study indicate DCLHb is not immunogenic in humans at doses evaluated clinically.

scholarly journals Chronic Wasting Due to Liver and Rumen Flukes in Sheep

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 549
Author(s):  
Alexandra Kahl ◽  
Georg von Samson-Himmelstjerna ◽  
Jürgen Krücken ◽  
Martin Ganter
Keyword(s):  
Fasciola Hepatica ◽  
Clinical Symptoms ◽  
Current Knowledge ◽  
Infection Intensity ◽  
Liver Parenchyma ◽  
Trematode Species ◽  
Helminth Infections ◽  
Juvenile Worm ◽  
Juvenile Stages ◽  
Common Liver Fluke

Grazing sheep and goats are constantly exposed to helminth infections in many parts of the world, including several trematode species that causes a range of clinical diseases. The clinical picture of flukes is dependent upon the organs in which they develop and the tissues they damage within the respective organs. Accordingly, infections with the common liver fluke Fasciola hepatica, which, as juvenile worm migrates through the liver parenchyma for several weeks, may be associated with hepatic disorders such as impairment of carbohydrate, protein and fat metabolism, followed by chronic wasting. In contrast, the lancet fluke Dicrocoelium dendriticum, which does not exhibit tissue migration and thus does not lead to major tissue damage and bleeding, also does not lead to significant clinical symptoms. Rumen flukes such as Cotylophoron daubneyi cause catarrhal inflammation during their migration through the intestinal and abomasal epithelium during its juvenile stages. Depending on the infection intensity this may result in a range of clinical symptoms including diarrhoea, inappetence or emaciation. In this review, we aim to provide an update on the current knowledge on flukes particularly concerning the clinical relevance of the most important fluke species in sheep.

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