Following publication of ‘Scottish Beaver Trial Independent Public Health Monitoring 2009-2014 Report and
Recommendations’ (Mackie, 2014), two pieces of complementary work were undertaken in parallel to assess
the potential contribution of reintroduced beavers in Scotland to the public health burden of disease
attributed to Giardia spp. and Cryptosporidium spp. parasites. The first, a risk assessment,
addressing the question ‘What is the likelihood that re-introduced beavers will have a significant
impact on the contamination of drinking water supplies with Cryptosporidium parvum and Giardia
lamblia?’ (Appendix 1), was conducted by Scottish Government’s Centre of Expertise on Animal
Disease Outbreaks (EPIC). This reviewed evidence from data and publications across the world, as
well as evidence from the beaver trial and SNH’s Tayside beaver reports, and used this to assess the
likely additional contribution of beavers to the risk associated with exposure to these parasites in
Scotland. The second, ‘What is the likelihood that beavers will be an important source of
contamination of drinking water supplies with Cryptosporidium parvum and Giardia intestinalis?’
(Appendix 2), was prepared by Health Protection Scotland (HPS), Scottish Parasite Diagnostic
Reference Laboratory (SPDL) and Drinking Water Quality Regulator for Scotland (DWQR). This
reviewed the diagnostics, surveillance and epidemiology of these infections in people in Scotland