In January and February 2000, researchers found low but detectable levels of the virus in 3 of 69 mosquito breeding pools in New York City, suggesting that the virus was able to survive the winter. To date, the virus has not been detected in Canada. Clinical management Symptoms appear 3 to 12 days after a person has been bitten by an infected mosquito. Symptoms range from mild fever and headache, occasionally accompanied by a maculopapular rash that expands from the trunk to the extremities, to severe headache, fever, stiff neck, muscle weakness and disorientation. 4 Many people remain asymptomatic.
Diagnosis is based on a serum IgM result.
Physicians who think a patient may be infected should phone their public health units for advice on laboratory testing. 5 Health Canada is working with the provinces and territories and with private industry to establish sentinel chicken surveillance. Coops have been placed in strategic locations from Saskatchewan to Atlantic Canada and tested weekly for the presence of West Nile virus. Wild birds, domestic animals and mosquito populations are also being monitored. Physicians are asked to report all cases of suspected viral encephalitis to their public health unit.