Usutu virus is a flavivirus that is closely related to the West Nile virus. It is mainly transmitted by mosquitoes and can cause a range of symptoms in humans, including fever, headache, and encephalitis. This virus was first identified in Africa in the 1950s, but over the years it has spread to other regions. There are several synonyms for the Usutu virus, including bird flu, mosquito-borne viral infection, and Japanese encephalitis. It is important to note that these viruses are distinct from each other, as they are caused by different agents and have varying symptoms. Therefore, it is essential to identify the specific virus causing the illness to determine the appropriate treatment.