West Nile Virus
West Nile Virus affects the central nervous system. About 80% of those who contract the virus may not show symptoms at all. Up to 20% percent of those infected may develop West Nile fever, which features mild flu-like symptoms. It is characterized by fever, headache, muscle aches, nausea, vomiting, and sometimes swollen lymph glands or a skin rash on the chest, stomach and back.
Health Canada and the U.S. Centers for Disease Control and Prevention estimate that fewer than 1% of those infected develop severe symptoms, and fewer than that experience life-threatening complications. People over 50, those with chronic health conditions (such as cancer, diabetes, alcoholism, or heart disease), and those with weakened immune systems are more likely to have serious health effects from West Nile virus.
About one out of every 150 infected people will develop severe illness. Severe symptoms include high fever, headache, neck stiffness, confusion, tremors (shaking), and convulsions (seizures). Infection with West Nile Virus can result in encephalitis (an inflammation of the brain) or meningitis (an inflammation of the layers that cover the brain). West Nile virus can cause the brain or spinal cord to swell and block the flow of blood to the brain. This could lead to a coma, paralysis, or even death.
According to Dr. Andrew Simor, head of the department of microbiology at Sunnybrook and Women's College Hospital, other infectious diseases (including influenza) pose a much greater risk to Canadians. For example, the flu is responsible for about 1,500 deaths in Canada each year.
But because of positive tests for mosquitoes carrying the virus in Ontario, most experts are urging Canadians to minimize their risk of mosquito bites.
You should consult your doctor if you have the following symptoms: