First Human Case Of West Nile Virus In Alberta Confirmed
Alberta's first human case of West Nile virus (WNv) for 2008 has been confirmed in a male in his thirties from the Chinook region. The infection, which has resulted in WNv non-neurological syndrome, was acquired while he was travelling in Saskatchewan.
“Although mosquitoes carrying WNv have not been found in the province this season, Albertans cannot let their guard down when outdoors,” said Dr. Gerry Predy, Acting Chief Medical Officer of Health. "This first confirmed case serves as a reminder that Albertans spending time outside need to wear mosquito repellent with DEET, as well as long sleeves, long pants and socks.”
The flu-like symptoms of WNv non-neurological syndrome, which occur within two to 14 days of infection, include headache, fever, chills, nausea, vomiting, fatigue, a possible skin rash or swollen glands. Most people who become infected show no symptoms. A mild illness may result in about 20 per cent of infected people and usually does not require medical attention. However, more serious symptoms of WNv neurological syndrome include stiffness of the neck, a worsening headache, disorientation, tremors or convulsions, muscle weakness, difficulty moving, and paralysis or coma. Physicians recommend seeing a doctor immediately if someone develops these symptoms.
Culex tarsalis mosquitoes, which are found in Alberta, are proficient at carrying the virus. The development and spread of the virus to humans depends on their level of activity. Each year, these mosquitoes are expected to reach their peak biting activity during July and throughout August. Ways to reduce your exposure to mosquitoes include emptying standing water from containers in your yard, and avoiding outdoor activities or covering up as much as possible at dusk and dawn when mosquitoes are most active.
Unlike previous years, this summer’s evening temperatures have not been consistently warm enough to facilitate the spread of infected mosquitoes. However, Albertans are reminded to take appropriate personal precautions whether or not Alberta surveillance finds mosquitoes carrying the virus.
In 2007, a total of 320 human cases of WNv were reported in the province, including two deaths.