First detection of microsporidia in animal faecal samples in urban parks in Leicester, UK.

Microsporidia are recognised as an emerging opportunistic group of pathogens. Recent studies highlight the possible zoonotic potential of various microsporidia species but transmission routes in humans and animals are still difficult to evaluate. The aim of this study was to determine the presence of human-related microsporidia (Enterocytozoon bieneusi and Encephalitozoon spp.) in animal faecal samples from urban parks in Leicester. A total of 117 faecal samples were collected during the winter months of 2016/17 from Victoria Park (LE1 7RY), Knighton Park (LE2 3RT) and Bradgate Park (LE6 0HE). A veterinarian identified the following animal species through visual analysis of each sample: 45 avian (10 pigeon, 5 songbird, 30 waterfowl), 1 fox, 60 deer, 5 dog and 6 uncertain species. Fresh faecal smears were prepared and stained using Weber’s modified trichrome stain following previous methodologies. The microscopic analysis of each smear provided the following preliminary results: 8 samples (6.8%; 1 songbird and 7 deer) were positive for Encephalitozoon spp. The positive avian sample was collected from Victoria Park and the deer samples from Bradgate Park. Our group previously detected microsporidia in faecal samples from dogs collected in the same months in 2015/16 but from another park in Leicester (Castle Gardens, LE1 5WH), indicating a possible distribution of microsporidia in the Leicester urban environment. However, further studies are required to determine if there is a risk for the population. Despite human-pathogenic microsporidia detected in avian species, the detection of these emerging human pathogens in deer has been poorly described. Urban animals, domestic and wild, may be carriers for microsporidia presenting a risk for human health that should be fully understood to prevent future infections