Brno loanvirus (BRNV) in bats inhabiting the urban area of Brno, Czech Republic

Bats are known reservoirs of various emerging pathogens, and have recently been found to host a novel hantavirus, named Brno loanvirus (BRNV), from the Mammantavirinae subfamily (family Hantaviridae, order Bunyavirales). Here we report BRNV detection in bats from the urban area of Brno, Czech Republic in March 2022. Specifically, we uncovered a high prevalence of BRNV (8.8%, 5/57) among hibernating bats (Nyctalus noctula) in urban area, which poses a risk of human exposure. The positive bats included adult females (3/9 positive), a juvenile female (1/32 positive), and an adult male (1/6 positive). All 10 juvenile males were negative. We used RT-qPCR to quantify the BRNV RNA levels in various bat organs, which yielded positive results for viral RNA in organs, including the kidneys, heart, spleen, brain, liver, lung, and gut, and in body cavity fluid. Among all tested organs, the liver showed the highest levels of viral RNA in 4 out of 5 animals examined (average Ct value of 20.8 ± 7.4). •Bats harbor various pathogens, including the novel hantavirus, Brno loanvirus (BRNV).•Our study identifies a high prevalence of BRNV among hibernating Nyctalus noctula bats.•RT-qPCR analysis reveals detectable levels of BRNV RNA in multiple bat organs.•The liver exhibits the highest viral RNA levels among all tested organs.•These findings underscore the potential risk of human exposure to BRNV in urban environments.