Table 2.

ARBOVIRAL AGENTS ASSOCIATED WITH MENINGITIS IN THE UNITED STATES

Family	Genus	Virology	Agents	Vector	Seasonal incidence
Togaviridae	Alphaviruses	Single-stranded positive sense RNA	Western equine encephalitis	Mosquito	Summer, early autumn
	Flaviviruses	Single-stranded positive sense RNA	St. Louis encephalitis	Mosquito	Summer, early autumn
			West Nile virus	Mosquito
Bunyaviridae	Bunyavirus	Single-stranded negative sense RNA	California/LaCrosse encephalitis virus	Mosquito	Summer, early autumn
Reoviridae	Orbivirus	Double-stranded RNA	Colorado tick fever	Tick	Spring, early summer