The only member of medical importance for the U.S. is the LaCrosse virus of the Bunyavirus genus. These are enclosed within the virion as helical nucleocapsids. L encodes the viral RNA dependent RNA polymerase. The G1 and G2 glycoproteins are present as spikes in the viral envelope. Bunyaviruses replicate in the cytoplasm and obtain their envelope by budding from the golgi.
Most infections are subclinical.
Phleboviruses Transmitted by phlebotomus flies and mosquitoes. Symtoms include fever and malaise but recovery is complete. Usually the illness is benign although there have been isolated reports of mortality. Virus can be spread by aerosols. It is maintained in a natural cycle involving rodents such as bank voles.