A survey of Cryptosporidium species in Skomer bank voles (Clethrionomys glareolus skomerensis)

A survey of Skomer voles ( Clethrionomys glareolus skomerensis ) conducted in August of 1994 and 1995 discovered that 51% of live-trapped animals were positive for Cryptosporidium species (Coccidia). Of the positive animals, 85% were shedding C. muris in their faeces, 5% C. parvum and 10% apparently both parasite species. On the U.K. mainland, the prevalence of Cryptosporidium in the bank vole ( Clethrionomys glareolus ) is a quarter of that on Skomer and the species normally found is C. parvum . Interest in C. parvum stems from the often severe diarrhoeal disease crypt osporidiosis which it can cause in humans and livestock. The parasite occupies the gastro-intestinal tract and is transmitted between hosts by the faecal-oral route. It has been suggested that wild rodents may be an important reservoir of infection by C. parvum for livestock. However, on Skomer island, C. muris , which is rarely found in livestock, is the dominant species infecting voles.