Cryptosporidium spp. in the English urban environment: a public health concern?

Several species of Cryptosporidium can infect humans and have been described as opportunistic parasites. Different outbreaks have been described in the UK as oocysts of these pathogens can spread through contaminated water and food as some species of Cryptosporidium, such as C. parvum, exhibit resistance to harsh environmental conditions. These pathogens have been found in animal faeces, thus we reported the presence of Cryptosporidium spp. in a dog faecal sample collected in a highly frequented public park in Leicester city centre (UK), after screening 9 topsoil and 18 faecal samples. As a result, and to determine potential risks to the Leicester population, we collected 132 animal faecal samples [37 deer, 13 dogs, 4 cats and 78 avian (27 uncertain due to diarrhoea, 25 pigeon, 14 waterfowl and 12 songbird)] across different parks in Leicester from June 2017 to May 2018. Animal faecal samples were appropriately screened using Kinyoun's acid-fast staining. We observed structures related to Cryptosporidium spp. in 16 faecal samples as follows: 10.3% avian (3 pigeon, 2 songbird and 3 diarrhoeic), 18.9% deer and 7.7% dog. However, and in order to characterise the risks to the local population, molecular analysis will be required to determine if the oocysts of Cryptosporidium spp. found are from anthroponotic species. Our results might highlight the relevance of performing environmental monitoring studies to determine the presence of these pathogens in the urban environment due to the unprecedented expansion of the urban media that is occurring to a global scale.