A survey of the exposure to Ostertagia ostertagi in dairy cow herds in Europe through the measurement of antibodies in milk samples from the bulk tank

Measurement of antibodies to Ostertagia ostertagi in bulk tank milk (BTM) has value as a diagnostic indicator for potential production losses and anthelmintic treatment responses in dairy herds. Most of the recent data on O. ostertagi antibodies in milk have been generated in Belgium and Canada; the purpose of this study was to determine the range of O. ostertagi antibody levels in several European countries. BTM samples were collected during the autumn of 2005 and 2006 from a total of 1185 dairy herds from dairy farming regions in Denmark, Germany, Ireland, Italy, the Netherlands, Portugal, Spain and the United Kingdom. Antibody titres to O. ostertagi were determined by indirect ELISA and expressed as optical density ratios (ODR). In addition, relationships between ODR and management practices were investigated. For each country the mean ODR and the 25th-75th percentile values were determined. Mean BTM ODR values in herds with access to yards, paddocks and pastures ranged from 0.3 in Italy to 0.6 in Portugal and the UK/Ireland. The BTM ODR values obtained in this study were generally lower than those described in the literature for Belgium, but comparable with those in Canada. Variations between different European countries appeared to reflect different husbandry practices, particularly those related to access to pasture. The association analyses showed correlations between the BTM O. ostertagi ODR, outside access and grazing management, consistent with the publications from Belgium and Canada. When diagnostic values appropriate for different production situations and environments have been further validated, the test will provide an objective, quantitative assessment of the O. ostertagi status of a dairy herd and the possible impact this may have on performance and potential responses to anthelmintic treatment. This represents a significant step forward in evidence-based medicine for dairy veterinarians, advisors and farmers

Monitoring gastrointestinal nematode and liver fluke infections in Belgium by bulk tank milk ELISA: are we making progress in parasite control?

Parasitic infections with gastrointestinal (GI) nematodes and liver fluke (Fasciola hepatica) are common causes of reduced productivity in ruminants. In this paper, the results of a voluntary monitoring campaign on helminth infections in Belgian dairy herds are summarized and discussed. From 2009 until 2011, a bulk tank milk sample was collected in autumn and analyzed by antibody-detecting bulk tank milk ELISA's to assess the level of exposure to GI nematodes and liver fluke. The number of farms participating in the survey increased over the years, from 1216 in 2009 to 1731 in 2011. The proportion of herds with high exposure to GI nematodes varied significantly between the three years, from 67% in 2009 over 70% in 2010 to 63% in 2011. The proportion of herds with high exposure to F. hepatica remained stable around 30%. Important regional variations were observed with levels of exposure to GI nematodes increasing from the north to the south of the country, whereas the distribution of F. hepatica was concentrated in the province of West-Flanders, the southern part of East-Flanders, Hainaut and the northern part of Luxembourg. It can be concluded that, when compared with surveys conducted in surrounding countries, the levels of helminth exposure in Belgium can be considered high, especially for GI nematodes. If the aim is to decrease levels of exposure in the future, this will likely require control methods based on altered timings of treatment and changes in pasture management

La contribution de l’helminthologie vétérinaire à l’helminthologie médicale

Infections with helminths are very common in animals: all grazing animals can be considered to be infected. Over the last decades considerable progress has been made especially in: (1) the development of innovative diagnostic tools, (2) the development of new anthelmintics and large surveys to evaluate their efficacy and to assess the emergence of anthelmintic resistance and, (3) addressing the economic impact of helminth infections such as weight gain and milk yield. The technical and scientific advances developed in the veterinary helminthology contributed also in many ways to medical helminthology. Three examples are briefly presented and discussed: (1) the introduction of new diagnostic tools and the pooling of samples, (2) the initiation of studies to assess the efficacy of anthelmintics in children by the faecal egg count reduction test and making recommendations for monitoring drug efficacy in the field, and (3) studies to assess the impact of treatment at delivery to improve breastfeeding and optimize infant growth.Les infections avec les helminthes sont très fréquentes chez les animaux : tous les animaux qui broutent peuvent être considérés comme étant infectés. Au cours des dernières décennies des progrès considérables ont été faits spécialement dans : (1) le développement de techniques de diagnostic innovatrices, (2) le développement de nouveaux anthelminthiques et de vastes études pour évaluer leur efficacité et la présence de résistance aux anthelminthique et (3) l’initiation des études sur l’impact économique des helminthoses comme le gain de poids et la production de lait. Les développements techniques et scientifiques en helminthologie vétérinaire ont aussi contribué de plusieurs façons à l’helminthologie médicale. Trois exemples sont brièvement présentés et discutés: (1) l’introduction de nouvelles méthodes de diagnostic et la mise en commun des échantillons, (2) l’initiation d’études pour évaluer l’efficacité des anthelminthiques chez les enfants par le test du taux de réduction des œufs fécaux et faire des recommandations sur leur l’efficacité et l’interprétation des données recueillies, et (3) études pour évaluer l’impact d’un traitement à l’accouchement pour améliorer l’allaitement et optimiser la croissance de l’enfant