Lyme disease: Prevention and risks

On this page

• How Lyme disease spreads
• Preventing Lyme disease
• Risks of Lyme disease
• Subscribe to the Zoonoses Bulletin

How Lyme disease spreads

Lyme disease is caused by a bacterium called Borrelia burgdorferi, which is spread through the bite of infected blacklegged ticks (deer ticks) and western blacklegged ticks.

In most cases, infected ticks need to be attached for at least 24 hours to transmit the bacteria that causes Lyme disease.

You may not notice a tick bite because ticks are tiny, and their bites are usually painless.

Learn more about:

• Ticks and tick-borne diseases

Preventing Lyme disease

There's currently no vaccine to prevent Lyme disease. However, there are clinical trials taking place in Europe and the U.S.

The best way to protect yourself from Lyme disease is to prevent tick bites. Check your provincial and territorial public health authorities to find out where infected ticks are most likely to be found.

Learn more about:

• How to prevent tick bites
• Provincial and territorial public health authorities

Risks of Lyme disease

You may have a higher risk of Lyme disease infection if you:

• spend time outdoors in and near areas with trees, shrubs, tall grass or piles of leaves where ticks can be found
• have pets that go outdoors because they can carry ticks into your yard or home, which could increase your chance of a tick bite
  • talk to your veterinarian about tick prevention for your pets

Learn more about:

• Canadian Veterinary Medical Association

Pregnant people

You should always take steps to prevent tick bites, including while pregnant.

During pregnancy, it's safe to use:

• approved insect repellent containing DEET or Icaridin (always follow label directions)
• permethrin-treated clothing (always follow label directions)

Infections during pregnancy can be concerning for you and your baby. If you're pregnant and don't feel well, or are concerned about your health, talk to your health care provider.

Current evidence related to Lyme disease and pregnancy is limited.

While transmission of Lyme disease during pregnancy is possible, the risk of passing Lyme disease to a baby during pregnancy is considered very low.

If a pregnant person has Lyme disease, they can be safely and effectively treated with antibiotics. Early treatment reduces the risk of potential placenta infection and complications.

If you think you may have Lyme disease, talk to your health care provider as soon as possible.

Breast milk

There have been no reports that Lyme disease can be passed to a baby through breast milk. Consult your health care provider if you're feeding breast milk and concerned about Lyme disease.

Learn more about:

• Society of Obstetricians and Gynaecologists of Canada: Lyme disease and pregnancy

Subscribe to the Zoonoses Bulletin

The Zoonoses Bulletin is an email subscription list that will provide you with regular updates from the Public Health Agency of Canada regarding our work on zoonoses. Zoonoses are infectious diseases that can be spread between animals and people including those that can be spread through the bite of a tick or mosquito.

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