Hepatitis A is an acute infectious disease of the liver caused by the hepatitis A virus, a small, non-enveloped hepatotropic virus classified in the genus Hepatovirus within the family Picornaviridae.
Sindbis virus is widely and continuously found in insects, such as Culex mosquitoes, in Eurasia, Africa, and Oceania. However, clinical infection in humans has almost exclusively been reported in northern Europe where it is endemic and where large outbreaks occur intermittently.