<i>Rocahepevirus ratti</i>: An underrecognised cause of acute hepatitis.

Zoonoses are responsible for many of all emerging infectious diseases as well as for those already established. <i>Rocahepevirus ratti</i> is a rat-originated virus related to the hepatitis E virus <i>(Paslahepevirus balayani)</i> but highly divergent genetically from this, with a high cross-species infection potential and zoonotic transmission. It can infect humans, leading to acute hepatitis, and is primarily transmitted through the consumption of contaminated water. <i>Rocahepevirus ratti</i> was first discovered in Germany in 2010. The first human case was described in 2017 in Hong Kong in an immune-compromised patient. The first case of chronic infection with <i>Rocahepevirus ratti</i> was described in 2023. A meta-analysis based on 38 studies published between 2000 and 2023 identified 21 cases in humans described up to this date and 489 infections in different animals. Raising awareness regarding this virus is essential, as there are probably many cases that remain undiagnosed, and the virus even has the ability to produce chronic infections in selected patients.