Halton Region Public Health: Office of the Medical Officer of Health
Quick facts
- Blacklegged ticks (BLTs) are the primary vector of Lyme disease and are present in Halton. Active tick surveillance shows that their population is expanding, and more ticks are testing positive for the bacteria that causes Lyme disease.
- The risk of acquiring Lyme disease in Halton remains low, however, locally acquired cases are trending upwards with twenty-eight confirmed cases in 2023 (up from only eight confirmed cases in 2022).
- In addition to Lyme Disease, BLTs can transmit other tick-borne diseases including anaplasmosis, babesiosis, and Powassan virus, however the risk of contracting these diseases remains low in Halton.
- Public Health Ontario and Ontario Health have developed a guidance document (external PDF) to support community pharmacists in prescribing antibiotic prophylaxis to prevent Lyme disease following a tick exposure.
Key messages for pharmacists
- Post-exposure prophylaxis (PEP) should be considered for certain patients with a recent tick exposure.
- Doxycycline should be used for post-exposure prophylaxis in adults and children of all ages. If doxycycline is contraindicated (e.g., allergy), there are no alternatives. Do not prescribe other antibiotics for post-exposure prophylaxis.
- If a patient is presenting with symptoms compatible with Lyme disease or any other reportable tick-borne disease, refer them to a physician or nurse practitioner.
- Asymptomatic individuals should be informed to monitor for symptoms for 30 days and seek care from a physician or nurse practitioner if symptoms develop.
- If your patients have a tick available for identification, please refer them to etick.ca (external link), a free tick identification platform.
Key messages for patients
- Ticks commonly live in wooded areas, tall grasses, and bushes and can be found almost anywhere in Ontario, including city gardens and parks. Halton is an established risk area for blacklegged ticks for 2024 (external PDF).
- Preventing exposure through personal protective measures are key to balancing the risk of tick-borne diseases like Lyme disease can be avoided, and the benefits of an active outdoor lifestyle preventing disease in humans.