What is West Nile virus?
West Nile virus is a mosquito-borne virus that can infect humans, birds, horses and other mammals. In most humans, West Nile virus infection causes a mild or moderate, short-lived flu-like illness, or causes no symptoms at all. However in some cases, particularly among persons 50 years of age and older, it can cause serious neurological diseases such as encephalitis, meningitis, or acute flaccid paralysis. West Nile virus first appeared in North America in New York City in 1999. Since then, the virus has spread across the continental United States. Visit www.cdc.gov for more information on West Nile virus nationally.
West Nile Virus (WNV) is a viral disease previously seen only in Africa, Asia, and southern Europe. This virus can cause encephalitis, an infection of the brain and the spinal cord. For the past three years, WNV has caused disease in the United States. In 1999, at least 62 people became seriously ill, and seven of those died. Since then, WNV has rapidly spread throughout 27 states and the District of Columbia. During the year 2000, 21 human cases of WNV encephalitis were reported in the United States, with two deaths. In 2001, 56 cases with 7 deaths were reported. In Ohio, WNV was first identified in a blue jay collected in Lake County. No human or horse cases were identified. It is expected that WNV will continue to be a disease threat in 2002. The West Nile Virus is spread to people by the bite of an infected mosquito. The principal transmitter of West Nile Virus is the Northern House Mosquito (Culex pipiens). Mosquitoes first become exposed to the virus when they feed on birds that
West Nile Virus (WNV), also known as West Nile Fever, affects wild birds, horses and humans. Young geese (goslings) are also susceptible to the disease and may show clinical signs when infected. WNV was named after the first human case was identified in the West Nile district of Uganda in 1937. In exceptional cases, WNV can cause meningitis and/or encephalitis resulting in coma or death. WNV is commonly found in Eastern Europe, Africa, West Asia and the Middle East. Its appearance in North America is recent, beginning in 1999. The disease is believed to be spread by infected migratory birds flying to breeding and wintering grounds. The Health Canada website contains useful information on the virus and the disease: http://www.hc-sc.gc.ca/pphb-dgspsp/wnv-vwn/index.html West Nile virus in animals In the United states, there have been cases of WN virus documented in a cat, domestic rabbit, chipmunk, gray squirrel, striped skunk, bats and in numerous horses. For animals which show symptoms
