RT Journal Article SR Electronic T1 West Nile fever: Here to stay and spreading JF Cleveland Clinic Journal of Medicine JO Cleve Clin J Med FD Cleveland Clinic SP 553 OP 560 VO 68 IS 6 A1 Pile, James YR 2001 UL http://www.ccjm.org/content/68/6/553.abstract AB The ultimate extent of West Nile virus’s range in North America is uncertain but is likely to expand in 2001. Spread chiefly by night-biting Culex mosquitoes, the virus results in infection that most often is asymptomatic or causes a self-limited febrile illness. The elderly, however, are prone to develop neurologic manifestations, including potentially fatal encephalitis.