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Dr Ellie Sherrard-Smith


I graduated from Cardiff University in 2007 with a BSc (Hons) in Zoology. I then worked at the Cardiff University Otter Project for two years. The principle role was to investigate trends in toxicology using a semi-aquatic mammal and, from a conservation perspective, to identify roads across England and Wales where death rates were unusually high so that mitigation could be implemented. Funded by the Environment Agency and Somerset Otter Trust we initiated a project to examine the distribution of biliary parasites in the UK. We also completed a tooth cementum analysis to understand the age structure of the otter population and explored seasonality using data on the female otter reproductive condition.


Position: Postdoctoral researcher
Location: Public Health England


I carried out my PhD from October 2009 until June 2013, supervised by Dr Jo Cable and Dr Liz Chadwick. My research followed the discovery of two species of digenean parasite in otter gall bladders, thought to be new to the UK. Pseudamphistomum truncatum was discovered by Vic Simpson (Simpson et al., 2005) in otters from Somerset, and Metorchis albidus was found subsequently at Cardiff University Otter Project (Sherrard-Smith et al., 2009). Both parasites have a complex life cycle utilising a snail and then a fish host before entering the definitive host e.g. the otter.


Since finishing my PhD, I have begun a post-doc with Public Health England which has been a fascinating insight into how science can affect policy. I am working on a project that is examining the cost effectiveness and health benefits of introducing point of care testing for genital chlamydia. The point of care concept aims to allow testing, results and treatment to be available during a single visit to a health care centre. A common example is the pregnancy test. Currently, the quickest test for chlamydia is the Cepheid 90minute test using PCR but developers are working on other tests that hope to be much swifter. My role is to analyse the current data from predominantly GU Medicine clinics (GUMCAD data) and the National Chlamydia Screening Program (NCSP) and identify clusters of similar levels of positivity (the number of positive cases for a given number of tests) and coverage (the number of tests completed for a given population). Watch this space and wear a condom! More generally, I am very interested in the overall patterns and processes that dictate parasite aggregation in the host populations – a universal interest of CRIPES members. I am still heavily involved in working on wildlife disease questions with friends from CRIPES.


Sherrard-Smith E, Stanton DWG, Cable J, Orozco-terWengel P, Simpson VR, Elmeros M, van Dijk J, Simonnet F, Roos A, Lemarchand C, Poledník L, Heneberg P, Chadwick EA. (2016) Distribution and molecular phylogeny of biliary trematodes (Opisthorchiidae) infecting native Lutra lutra and  alien Neovison vison across Europe. Parasite International 65:163-170. doi: 10.1016/j.parint.2015.11.007

Sherrard-Smith E., Chadwick E.A., Cable J. (2014). The impact of introduced hosts on parasite transmission: opisthorchiid infections in American mink (Neovison vison) Biological invasions 16:6. (

Chadwick E.A., Cable J., Chinchen A., Francis J., Guy E., Kean E.F., Paul S.C., Perkins S.E., Sherrard-Smith E., Wilkinson C., Forman D. (2013). Seroprevalence of Toxoplasma gondii in the Eurasian otter (Lutra lutra) in England and Wales. Parasites and Vectors 6: 75

Sherrard-Smith E., Chadwick E.A., Cable J. (2013). Climatic variables are associated with the prevalence of biliary trematodes in otters. International Journal for Parasitology 43: 729-737

Sherrard-Smith E., Chadwick, E.A., Cable, J. (2012). Abiotic and biotic factors associated with tick population dynamics on a mammalian host: Ixodes hexagonus Infesting on Otters, Lutra lutra. PLoS One 7: e47131
Sherrard-Smith E., Cable J., Chadwick E.A. (2009). Distribution of Eurasian otter biliary parasites, Pseudamphistomum truncatum and Metorchis albidus (Family: Opisthorchiidae), in England and Wales. Parasitology 136: 1015-1022
Sherrard-Smith E., Chadwick E.A. (2010). Age structure of the otter (Lutra lutra) population in England and Wales, and problems with cementum ageing. IUCN Otter Specialist Group Bulletin 27: 42-49
Chadwick E.A., Sherrard-Smith E. (2010). Pregnancy among otters (Lutra lutra) found dead in England and Wales: Foetal development and lack of seasonality. IUCN Otter Specialist Group Bulletin 27: 33-41.