First detected in New York in the fall of 1999, the West Nile virus has recently spread from the east coast to Louisiana and Arkansas, putting Texas veterinarians on alert for what may be the inevitable migration of the virus into the state.
"West Nile encephalitis belongs to the same group of diseases as St. Louis encephalitis, the Flaviviridae family, and is named for the area in Uganda, Africa where it was first detected in the 1920s," said Dr. Ian Tizard, veterinarian and director of the Schubot Exotic Bird Health Center at the College of Veterinary Medicine at Texas A&M University.
"This insect-borne virus spreads through the sting of infected mosquitoes and is carried by birds who act as reservoirs. While humans may become infected, the condition isn't usually too serious. Most healthy adults contracting the disease in the United States experience flu-like symptoms with no further complications. However, there have been a few fatal cases involving older patients. Among animals, the virus is most fatal to birds and horses."
Because of the susceptibility of wildlife, veterinarians who notice an unusually high number of dead birds (particularly crows) are asked to file a report with the Zoonosis Control Division of the Texas Department of Health.
In addition, surveillance programs are in place for the regular testing of dead birds, horses, captive waterfowl, and mosquitoes. The only commercial vaccine currently available is formulated for horses.
Since first detected, the virus has been largely seasonal
in occurrence with most cases reported during warm weather
months. The temperate Texas climate, however, is expected to
Contact: Keith Randall
Texas A&M University