In Saskatchewan, Canada, there were 89 probably human cases of West Nile virus infection last week, this week the figure has jumped to 339. Of the confirmed cases so far, seven are of the neurological syndrome variety, the most serious. Officials have said that the first half of August is always the period when numbers tend to peak.
According to authorities, a person in Saskatchewan currently runs a one-in-ten chance of being bitten by an infected mosquito. In 2003 there were 947 confirmed human cases of West Nile virus infection in Saskatchewan, the highest number in the region ever – sixty-three people developed the severe form, while seven died. Experts say this has definitely been the worst year since 2003.
June was a wet and warm month in Saskatchewan, July was hot as were the first 15 days of August – ideal conditions for the mosquitoes to thrive. As temperatures start to slide, as they are expected to at the end of this month, so will the number of mosquitoes, leading to a drop in the number of new human cases.
What Is West Nile Virus?
West Nile Virus (WNV) can be a serious disease. It is established as a seasonal epidemic in North America, peaking in the summer and persisting well into the fall (autumn).
The virus spreads to humans and other animals through the bite infected mosquitoes. The mosquito becomes infected when it feeds on infected birds. Less commonly, WNV can also spread through transfusions, transplants and mother-to-child (pregnancy or breastfeeding). It does not spread if you touch or kiss an infected person.
West Nile Virus Symptoms
Severe Symptoms – Extremely Rare
Only about 1 in every 150 infected people will develop severe illness. Severe illness may include:
— high fever
— headache
— neck stiffness
— stupor
— disorientation
— coma
— tremors
— convulsions
— muscle weakness
— vision loss
— numbness
— paralysis
The symptoms may continue for several weeks. Neurological effects are sometimes permanent.
Milder Symptoms – Affects 20% of Infected People
About 80% of infected people show no symptoms at all. Mild symptoms may include:
— Fever
— headache
— body aches
— nausea
— vomiting
— swollen lymph glands
— skin rash on the chest, stomach or back
Symptoms generally last from a few days, and less commonly a few weeks.
Useful links from the Centers for Disease Control and Prevention (CDC)
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— About West Nile Virus – Health Canada
Written by: Christan Nordqvist