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Would you like to post something to the bulletin board? Please email your message. *********************************************************** Government of The Government of Canada is providing free access for Canadians to the 14
journals published by NRC Research Press, a service offering of the Canada
Institute for Scientific and Technical Information (CISTI). Beginning January
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with the support of the Treasury Board of Canada, which is responsible for
overseeing the policies under which the Depository Services Program operates. Canadians can currently access the 14 journals at http://researchpress.nrc.ca/ .They are: · Biochemistry and Cell Biology WEST NILE VIRUS ENCEPHALITIS: A NEW
ZOONOTIC DISEASE FOR James P. Goltz In mid August, some wild crows were found dead on the grounds of the Bronx Zoo in New York city, but phone reports of dead crows elsewhere in the city had begun earlier in the summer. Around the same time, there were reports of encephalitis, originally thought to be St. Louis encephalitis, in humans. By late August, crow deaths were reported in multiple areas in New York state. Deaths in captive birds began in the Bronx Zoo in early September and continued over a three-week period. Horse deaths, initially attributed to a parasitic infection transmitted by opossums, began in New York state in late August. West Nile Virus was isolated from crows, other wild birds, zoo birds, humans, horses and mosquitoes, and is now known to be the cause of these disease problems and mortality. What is West Nile Virus and why is it cause for concern? It is a virus that may cause encephalitis (inflammation of the brain) and is spread only by the bites of infected arthropods, mainly mosquitoes (at least 43 species worldwide) and, to a lesser extent, ticks. There is no evidence of direct animal to animal, or animal to human transmission. Wild birds are the primary hosts but the virus may also infect humans, domestic fowl, some domestic mammals (e.g., horses, cats), and non-human primates. In humans, West Nile Virus may cause mild disease with fever, frontal headache, muscle aches, swollen lymph nodes and skin rash, and less commonly may result in severe disease that is marked by headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, occasional convulsions, paralysis and death. Disease is usually more severe in the elderly. The incubation period (between infection and the onset of disease) in humans is usually 5 to 15 days. No approved vaccines against this virus are available for use in humans or animals. Prior to 1999, the virus was only reported from Africa, Asia and Europe, and had never been found in the Western Hemisphere. The 1999 New York area outbreak of West Nile Virus caused disease in at least 60 people and resulted in 7 human deaths, including one Canadian who visited New York from Toronto. It likely killed at least 5000 wild birds, mainly American Crows, but also caused deaths in at least 17 other species of native wild (Blue Jay, Fish Crow, Ring-billed Gull, Herring Gull, Yellow-billed Cuckoo, Rock Dove, American Robin, Red-tailed Hawk, Broad-winged Hawk, Cooper's Hawk, American Kestrel, Belted Kingfisher) and captive (Bald Eagle, Laughing Gull, Sandhill Crane, Black-crowned Night Heron, Mallard) birds, as well as Chilean flamingos and unspecified species of pheasants and cormorants. The virus killed at least one cat and caused disease in at least 22 horses (at least 10 of which died or had to be euthanized), while at least 21 other horses became infected without showing any sign of disease. Although most cases of disease and death in humans and animals occurred in New York state, some bird mortality was also detected in nearby New Jersey and Connecticut, and one affected dead crow was found in Maryland. Health officials responded to the West Nile Virus outbreak with public education campaigns, surveillance of mosquitoes and dead birds, and mosquito control programs. It is not known how the virus arrived in the New York area but it is hypothesized that it may have been introduced by migrating birds, legal or illegal imports of birds, a viremic person, or the transport of infected mosquitoes via aircraft. Consequently, several countries have adopted measures to prevent importation of the virus from New York. It is now known that West Nile virus
successfully overwintered in Connecticut and the New York area. Canadian
public health officials fear that this virus may be brought to eastern Canada
next spring by migrating birds infected with the virus. As in mammals, not
all infected birds will become sick or die. Wildlife agencies and
entomologists in the southern What can be done to safeguard against and prepare for West Nile Virus? It is important to be well informed, and to avoid being bitten by mosquitoes by adopting personal protective measures when engaging in outdoor activities where mosquitoes are likely to be encountered, especially at dawn, at dusk and at night (and especially if travelling to areas where the virus is known to occur). In addition, please keep watch for any warning signs that our American Crow population may provide. Unusual outbreaks of crow mortality should be reported to Dr. Jim Goltz at the Provincial Veterinary Laboratory [(506) 453-5412] or Dr. Pierre-Yves Daoust of the Canadian Cooperative Wildlife Health Centre (located at the Atlantic Veterinary College) [(902) 566-0667], especially if neurologic disease is suspected. Suspect dead birds should be placed in leakproof plastic bags and promptly refrigerated until they can be delivered to a laboratory for testing. Remember, there's no need to worry about catching the West Nile Virus directly from wild birds; however, avoiding handling any sick or dead animal with your bare hands will help prevent the transmission of other possible diseases. The following internet links are provided for those who would like additional information on West Nile Virus: http://www.cdc.gov/ncidod/eid/vol5no5/hubalek.htm#20 http://www.cdc.gov/ncidod/dvbid/arbor/arboinfo.htm http://www.cdc.gov/od/oc/media/pressrel/r990924.htm http://www.umesc.usgs.gov/nwhchome.html |