Interesting article in Veterinary Times July 16th edition on liver fluke in adult dairy cattle.

The article quotes a survey published in 2005 which estimated the prevalence of fasciola hepatica infection in dairy herds to be 45 per cent in England and 86 per cent in Wales, by looking at ELISA tests on bulk milk samples (Salimi-Bjestani et al, (2005) Veterinary Record 156:729-73). I don't know what the sensitivity and specifity of this ELISA was but I'd guess that would be a conservative estimate of the spread of the disease.

These are interesting figures to ponder if you consider the recent report concerning the interaction between liver fluke and the comparative cervical test used to detect bovine tuberculosis.

The author, Adam Martin, raises the issue of warmer, wetter weather favouring the spread of liver fluke and its potential to spread to humans.

He also talks about the difficulties of detecting the disease due to its long pre-patent period (when an animal is infected but not yet shedding anything that you can detect in the faeces). So the proportion of animals with clinical disease is very low and the numbers with sub-clinical disease are estimated to be high.

He also makes the comment "Unfortunately, flukicides are available for purchase over the counter without a prescription from a veterinary surgeon, which means many products are often used inappropriately."

That's an interesting comment to reflect on....