Hamiltonian contracts West Nile virus

Someone in Hamilton has contracted West Nile virus, the city announced today.

This marks the first confirmed case in a human in the city this year. To date, 23 of the city's mosquito traps have tested positive for West Nile.

"The risk of being infected with West Nile virus exists locally. Please continue to take precautions to avoid being bitten by mosquitoes," said Dr. Jessica Hopkins, Hamilton's associate medical officer of health in a statement.

"We know that taking precautions is important, such as applying insect repellent with DEET when you're outside."

The risk of West Nile virus will drop once there is a heavy frost to reduce the number of mosquitoes, the city says. The city did not provide any information about the infected person's condition.

According to The Centers for Disease Control (CDC), 70 to 80 per cent of people who become infected with West Nile virus do not develop any symptoms. About one in five people who are infected develop a fever with other symptoms like headache, body aches, joint pains, vomiting, diarrhea, or rashes.

Most people with that type of West Nile virus disease recover completely, the CDC says, but the fatigue and weakness can last for weeks or even months.

Though rare, serious illness can also occur. Less than one per cent of people who contract West Nile develop a serious neurological illness like encephalitis or meningitis, which includes inflammation of the brain.

The city says that precautions that can be taken to avoid being bitten by mosquitoes include:

• Using a mosquito repellent containing DEET (manufacturer's instructions should be followed carefully)
• Avoiding areas with high mosquito populations
• Wearing light-coloured, tightly-woven, loose-fitting clothing, including long sleeves, pants and a hat, to cover exposed skin (in trails or where there is dense bush)
• Making sure all windows and doors in your home have screens that are in good condition
• Taking extra precaution from dusk to dawn when mosquito activity is particularly high

As part of prevention methods, the city treats catch basins and stagnant water on public land like ditches and ponds to kill mosquito larvae.