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

SummaryBovine tuberculosis (bTB), caused byMycobacterium 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 ofFasciola hepatica and the disclosure of bTB at the animal ‐level using large surveillance datasets.We utilised a dataset of 138,566 animal records from an abattoir from Northern Ireland (2011 ‐2013). The presence ofF. 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 non‐reactors 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 in...
Source: Transboundary and Emerging Diseases - Category: Veterinary Research Authors: Tags: Original Article Source Type: research