Emerging infectious diseases pose an extreme risk for animal populations. In the early 2000s, the Lloviu virus (LLOV) presumably caused mass mortalities in Schreiber’s bat population in Spain, Portugal, and France. After more than a decade, LLOV re-emerged in 2016 in Hungary along with two additional possibly connected mass mortality events from 2013 to 2016. In addition, we recently confirmed the presence of the virus in dead animals in January of 2019 and living bats in autumn 2019 at one previously affected roost in Hungary, which presented evidence for the continuous circulation of LLOV there. Our findings underscore the potential of viral pathogens to severely affect bat populations, causing mass mortalities. Moreover, Filoviruses – where LLOV belongs – are among pathogens that are the most likely to jump between hosts, therefore posing a direct risk of human infections. In our article published in Ecohealth, we proposed several mitigation measures to reduce negative effects of LLOV on bat populations, and to prevent human infections.