Liver fluke is a common and highly pathogenic parasite affecting sheep and cattle in the UK.  It causes acute disease in sheep, chronic disease in sheep and cattle, but more ubiquitous are its effects on animal production.  Burdens as low as 10 parasites can result in reduced growth weights and milk yields. Liver fluke is identified as one of the top five diseases impacting production and welfare for both sheep and cattle in the UK (Ruminant Health and Welfare 2021). 

Control of liver fluke is complicated. Traditionally, farmers treat stock based on previous history and established on-farm routines, but these practices are not sustainable; drug use is undirected and often unnecessary. Resistance to triclabendazole has developed in F. hepatica populations globally and is particularly prevalent in Britain. As our climate changes, the timing of infectious challenge has become much less predictable meaning treating at traditional times of year do not align with when animals become infected. Being able to target treatment at animals when they need it is the way forward, hence rapid and easy to use diagnostics are imperative. 

The aim of this proposal was to evaluate a prototype lateral flow diagnostic kit, developed at the University of Liverpool, to aid on-farm diagnosis of infection. 

The lateral flow test was used on 12 farms, all based in Cumbria. One hundred and forty sheep and 40 cattle were sampled, and each farmer ran the test themselves. Feedback on the test was obtained through a project meeting with farmers and their vets. The lateral flow results were available within 10 minutes and were subsequently validated by testing serum and faecal samples in the lab. 

Outputs from the project showed that the test had a diagnostic sensitivity of 71.3% in sheep and 76% in cattle, and a specificity of 82% in sheep and 81% in cattle when compared to the University of Liverpool lab based diagnostic ELISA. Farmers and their vets expressed enthusiasm for the test and stated it could be very valuable in diagnostic testing on farm. They identified specific areas for improvement to make it more user friendly, and this information will be fed into the final design of the test. They also identified cost and decision support which would need to be put in place, making the test an essential tool for livestock farmers.

Contact details:

Professor Diana Williams

Department of Infection Biology and Microbiomes

University of Liverpool