ABSTRACT
Introduction: Recent studies have shown that bats are the reservoir hosts of several novel viruses, increasing the interest in bats as potential vectors of zoonotic pathogens. Several studies investigated the presence of infectious agents in bats, but their impact on the individual host and their importance on bat mortality is largely unknown. The aim of this study was to describe the microbiological and histopathological findings in 77 deceased bats belonging to nine European species (families Vespertilionidae and Molossidae). Materials and Methods: Bat carcasses were collected in the Piedmont region (Italy) by the Unconventional Rehabilitation Centre (CANC), Torino University, and submitted to necropsy. Species, age and sex of each bat were recorded. Virological (orthoreovirus, coronavirus, flavivirus, rhabdovirus, poxvirus, kobuvirus) and histopathological examinations were performed on the main organs (liver, spleen, kidney, gut, lung, heart and brain). Results: Traumatic injuries (fractures, haemorrhages, skin lesions;43%) and predation injuries (8.4%) represented the two main causes of death. Regardless of species, age and sex, the pathological examination revealed inflammatory/degenerative lesions mainly involving liver (non-suppurative hepatitis and vacuolar degeneration;20.8%) and lung (bronchopneumonia;29.9%). Coronavirus, flavivirus, rhabdovirus and kobuvirus were not detected. Poxviruses were detected in three lungs, two with pneumonia, and 14.3% of animals were positive for reoviruses. Conclusions: This study demonstrates the importance of inflammatory lesions in bat mortality, and shows that bats can harbour infectious agents. However, there is no evidence that Italian bats may represent a severe risk for human health.