Authors

R Byrne¹; C V Holland¹; N Marples¹;  ¹ Trinity College Dublin, Ireland

Discussion

The European badger (Meles meles) is Ireland's largest terrestrial carnivore. It was first identified as a wildlife reservoir of bovine tuberculosis (bTB) in Ireland in 1972, generating an increased research focus on the badgers' behaviour and ecology to aid bTB control. However, the helminth parasite community of the Irish badger has been continuously overlooked and under-researched, despite the established links between macroparasites and immune suppression and immunodulation. 

We are the first to describe the parasite community of the Irish badger, with an emphasis on helminth species. We sampled Western counties and Eastern counties, male and female badgers, and bTB positive and negative badgers, allowing the effects of all these factors to be interrogated. 

Of the 289 badgers sampled there was a prevalence of 61% for hookworm infection. The average worm burden was 22.5 with a range of 1-500 worms. As seen in many other hosts there was an aggregated distribution of helminths with a small number of individuals harbouring the majority of worms. Little diversity within the helminth parasite community was observed. This is surprising given that badgers are fossorial feeders, eating in and around soil, and many helminth species are transmitted through faecal contaminated soil. 

Additionally, as part of this project both gross organ dissection and faecal egg counts were used as diagnostic tools. In contrast to what is observed in humans, as the intensity of worm burden increased so did the number of eggs shed by the adult hookworm with egg per gram counts of over 3000 being recorded. Given the rarity of having both egg count data and adult worm burden, this presented the unique opportunity to evaluate the sensitivity of faecal egg counts. For the diagnosis of hookworm infection, faecal egg counts had a low sensitivity when compared to the diagnostic gold standard of adult worm burden. 

The parasite communities of Irish badgers' present challenges and opportunities for wildlife management, farmers and ecologists. A further understanding of the interplay between parasitic and bTB infection in the context of Ireland and its badger population is necessary for future management of bTB and co-infected helminth parasite outbreaks.