West Nile virus turns up in London mosquitoes

Public health officials are urging residents to take precautions to avoid mosquito bites after a trap in London turned up West Nile virus-carrying bugs — the first finding of the virus this summer.

The Middlesex London Health Unit said the trap was near Springbank Drive and Wharncliffe Road, part of the agency’s regular mosquito monitoring program. West Nile has already shown up across Southwestern Ontario. Earlier this month, virus-positive mosquitoes turned up in a Windsor trap. On Monday, Southwestern Public Health — the agency that oversees Elgin and Oxford counties — said mosquitoes caught in a trap in Woodstock tested positive for West Nile virus. A dead crow found in Sarnia’s north end in late July tested positive for the disease, Lambton Public Health announced Tuesday. Getting positive results in traps and birds is not uncommon at this time of year, said vector-borne disease co-ordinator Jeremy Hogeveen.

“It’s very normal. Basically almost every time this year, the end of July, early August, is when we start to see traps go positive for West Nile,” he said. “That’s slowly when we start to see the human cases show up, in August, September and even into October.” Most people — up to 80 per cent, the health unit says — who are infected with West Nile virus do not get sick. People who do get sick from the virus typically get mild flu-like symptoms. Less than one per cent of people infected with West Nile get seriously ill. The health unit wants homeowners to reduce standing water — a breeding ground for mosquitoes — by emptying rain gutters, flower pots, children’s toys and bird baths. People should wear light-coloured, long-sleeved shirts and pants when they’re outside, stay indoors around dawn and dusk when mosquitoes are most active and use insect spray that contains DEET or Icaridin.

“While we continue our mosquito surveillance and control efforts in the region, we want to remind people across London and Middlesex County that they need to protect themselves and their families from mosquito bites,” vector-borne disease co-ordinator Jeremy Hogeveen said in a statement. Since early May, the health unit has been doing weekly mosquito monitoring at 250 standing water sites. The agency also has hanging traps to capture live mosquitoes.