As can be expected at this time of year, the Region of Waterloo has its first human case of West Nile virus.
Dr. Hsiu-Li Wang, associate medical officer of health for the Region of Waterloo, says some years they have no human cases, while others they’ll have a handful.
“Every year we can expect it to be present. It’s in mosquitoes and it can pass to humans. Not all types of mosquitoes, but certain types that can carry the West Nile virus,” Wang said.
They start their campaign every May to let people know how to protect themselves from contracting the virus in the warmer months.
“We also have things that provide us an indication of the degree of West Nile activity. So for instance we have human case monitoring. We also put out mosquito traps and try to see what kinds of populations are out there and if they’re infected with the virus,” Wang explained.
She says they’ve had their first indication this season, with one person testing positive for the virus. It’s important to note there is no human to human transmission.
“The significance of this is just that it confirmed that West Nile activity has indeed begun in our region and really reinforces the need for people to take precautions. So things like avoiding activity between dusk and dawn, if you do go out make sure you wear repellant with DEET, cover yourself up in light-coloured clothing, long sleeve shirts and pants, and try to remove standing water from your property,” Wang said.
Other ways to decrease your odds of attracting a mosquito include ensuring all windows and doors are closed tightly and changing water in livestock watering tanks and bird baths at least weekly. DEET is not recommended to be used on children less than six months old.
West Nile virus symptoms are pretty general, like having a fever, headache, muscle aches, and fatigue. The best way to find out if you have it is to get your doctor to do a blood test. Wang notes doctors are aware when the virus is present in the region, and are on the lookout for it in their patients.
“Most of the time West Nile cases are actually either asymptomatic, that means no symptoms, or they don’t have serious complications. In some serious instances, about less than one in 100, there can be more severe complications, like some neurological complications. These are rare,” Wang said.
People are asked to take precautions between May and September. After that it becomes too cold and mosquitoes are no longer active. The virus sits dormant then.
“We’ve been monitoring the population of mosquitoes out there so that we can larvicide, that’s sort of like kill the mosquitoes. We have these populations growing in things like catch basins and storm water management ponds. Obviously it’s not 100 per cent and we need people to take precautions,” Wang said.