Determining the Prevalence and Seasonality of Fasciola hepatica in Pasture-based Dairy herds in Ireland using a Bulk Tank Milk ELISA

Yris Bloemhoff,Martin Danaher,Grace Mulcahy,Andrew Forbes,Ríona Sayers,Barbara Good,Eric Morgan,Mary Sekiya

doi:10.1186/s13620-015-0042-5

Abstract

BackgroundFasciola hepatica is a helminth parasite of global importance in livestock, with major economic impact. However information on F. hepatica infections in Irish pasture-based dairy herds is limited. Therefore this study was conducted in order to determine the prevalence, seasonality and management factors associated with F. hepatica. A total of 319 Irish dairy herds were selected for this study. Bulk tank milk (BTM) samples were collected from 290 dairy farms on a quarter year basis, while from a further 29 dairy farms BTM samples were collected on a monthly basis to provide a more detailed pattern of F. hepatica exposure in Irish herds. BTM samples were analysed using a commercially available F. hepatica antibody detection ELISA. Furthermore, within-herd prevalence of F. hepatica was assessed in a subset of these 29 herds (n = 17); both individual serum samples and bulk tank milk samples were collected.ResultsA within-herd prevalence of ≤ 50 % was found for herds with negative bulk tank milk samples. The mean prevalence of the 290 study herds was 75.4 % (Range 52 %–75.1 %), with the highest prevalence being observed in November (75.1 %). The seasonal pattern of F. hepatica shows elevated antibodies as the grazing season progressed, reaching a peak in January. A significant association was found between F. hepatica and age at first calving.ConclusionThis study demonstrates that F. hepatica is present in a large proportion of Irish dairy herds and provides a basis on which control practices, particularly in adult dairy cows, can be reviewed.

Highlights

Fasciola hepatica is a helminth parasite of global importance in livestock, with major economic impact
Diagnosis of F. hepatica was previously based on coprological techniques alone, but with the advent of coproantigen, copro-Polymerase chain reaction (PCR) and enzyme linked immunosorbent assays (ELISA) for the diagnosis of F. hepatica in sera and milk, detection of F. hepatica has become more sensitive [4, 5]
As only limited studies regarding the prevalence of F. hepatica infections exist in Ireland and heretofore no nationally representative study has been completed, the primary objective of this study was to determine the prevalence of F. hepatica in a geographically representative group of Irish dairy herds

Summary

Introduction

Fasciola hepatica is a helminth parasite of global importance in livestock, with major economic impact. The use of ELISA on bulk tank milk (BTM) samples has allowed monitoring of an entire herd for F. hepatica status, and–when applied to individual milk samplesdetermination of the within-herd prevalence of F. hepatica [5, 6]. Control of F. hepatica is generally achieved using anthelmintic treatment, more widespread application of herd ELISA status data will allow greater evidence-based control of F. hepatica at farm level [6]. This in turn will contribute to more appropriate and sustainable use of flukicide treatments in dairy herds [7], which could result in a reduction in anthelmintic use and reduce selection for anthelmintic resistance [8]

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