What is Lyme disease?

Lyme disease is a serious illness that can be spread to people by the bite of infected blacklegged ticks (also known as deer ticks). Most cases of Lyme disease can be treated successfully with antibiotics. However, if left untreated, symptoms can last from months to years and can cause serious health problems.

Blacklegged ticks live in woodlands, tall grasses and bushes, and are found throughout Ontario – including the five eastern counties. The number of infected blacklegged ticks is increasing each year.

Click here to check out the map of estimated risk areas for Lyme disease in Ontario.

Ticks are most active in the summer months, but can be found at any time of the year when the temperature is above freezing. Adult ticks are about the size of a sesame seed, while the immature nymphs can be as small as a poppy seed. When they’re full of blood, they can be as large as a grape.Not able to fly, ticks move slowly on the ground, or settle on tall grass.

Their bites are usually painless, so you may not know you’ve been bitten. That's why it's important to take steps to protect yourself, and to be on the lookout for ticks and the symptoms of Lyme disease.

A tick bite doesn’t always result in Lyme disease. A tick has to be infected with Lyme disease bacteria in order to pass it on to you. The risk of getting Lyme disease from a tick bite is believed to be greater if an infected tick has been attached to you for more than 24 hours.