Liver fluke (Fasciola hepatica) co-infection with bovine tuberculosis (bTB) in cattle: A retrospective animal-level assessment of bTB risk in dairy and beef cattle.

Autor:	Byrne AW; AFBI Stormont, Agri-Food and Biosciences Institute (AFBI), Belfast, UK.; School of Biological Sciences, Queen's University Belfast, Belfast, UK., McBride S; AFBI Stormont, Agri-Food and Biosciences Institute (AFBI), Belfast, UK., Graham J; AFBI Stormont, Agri-Food and Biosciences Institute (AFBI), Belfast, UK., Lahuerta-Marin A; AFBI Stormont, Agri-Food and Biosciences Institute (AFBI), Belfast, UK., McNair J; AFBI Stormont, Agri-Food and Biosciences Institute (AFBI), Belfast, UK., Skuce RA; AFBI Stormont, Agri-Food and Biosciences Institute (AFBI), Belfast, UK., McDowell SW; AFBI Stormont, Agri-Food and Biosciences Institute (AFBI), Belfast, UK.
Jazyk:	angličtina
Zdroj:	Transboundary and emerging diseases [Transbound Emerg Dis] 2019 Mar; Vol. 66 (2), pp. 785-796. Date of Electronic Publication: 2018 Dec 23.
DOI:	10.1111/tbed.13083
Abstrakt:	Bovine tuberculosis (bTB), caused by Mycobacterium bovis, remains a persistent problem for cattle industries in endemic countries. The frequency, quality, and performance of tests, and the presence of wildlife reservoirs, have been identified as impediments to eradication. Recently, exposure to helminth infection (Fasciola hepatica) has been associated negatively with the disclosure of bTB. Here, for the first time, we assess impact of concurrent infections of Fasciola hepatica and the disclosure of bTB at the animal-level using large surveillance datasets. We utilized a dataset of 138,566 animal records from an abattoir from Northern Ireland (2011-2013). The presence of F. hepatica infection was assessed from macroscopic tissue inspection at abattoir. Multivariable models were developed to assess co-infection associations with bTB status based on: Single Intradermal Comparative Tuberculin Test (SICTT), lesion, bacteriological confirmation, including either all animals, or only skin-test negative animals (lesions at routine slaughter; LRS; confirmed nonreactors at routine slaughter; cNRs) or positive (reactors) animals alone, respectively. The relationship between skin tuberculin reaction sizes and fluke status was also explored for a subset of animals with field recordings (n = 24,680). Controlling for known risk factors (e.g., climatic, herd, and individual level characteristics), we did not find significant associations between the SICTT (standard or severe interpretation), lesion, nor confirmation status of animals and their liver fluke status. The only exception was a negative association between liver fluke positivity, and LRS or cNRs, respectively; though effect-sizes were small (e.g., LRS Odds-Ratio: 0.87; 95% CI: 0.76-1.00). There was limited evidence of a relationship between tuberculin reaction sizes during SICTT testing and liver fluke infection status. These data do not support the contention that the detection of bTB using skin-tests or reactor postmortem follow-up may be compromised by co-infection at a population level, but the relationship with lesion formation (pathogenesis) may indicate an impact for postmortem surveillance. (© 2018 Crown copyright. Transboundary and Emerging Diseases © 2018 2018 Blackwell Verlag GmbH.)
Databáze:	MEDLINE
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