Ticks: bites and diseases transmitted in Quebec
Main ticks in Quebec and diseases transmitted
| Species | Common name | Diseases transmitted in Quebec | At-risk regions |
|---|---|---|---|
| Ixodes scapularis | Black-legged tick / deer tick | Lyme disease (B. burgdorferi) ++ + Anaplasmosis (A. phagocytophilum) + Babesiosis (B. microti) + Ehrlichiosis | Montérégie + Eastern Townships + Montreal + Laurentides + Bas-St-Laurent (expanding) |
| Dermacentor variabilis | American dog tick | Rocky Mountain spotted fever (R. rickettsii) - rare in Quebec + tick paralysis | Southern regions + rare in Quebec |
| Amblyomma americanum | Lone star tick | Ehrlichiosis + STARI (B. lonestari) + Tularemia | Rare in Quebec - growing presence in the U.S. |
Removing an attached tick - correct technique
- Equipment: fine-nosed tick forceps (or fine forceps without teeth) + alcohol 70 % to disinfect + do not use: bare fingers + petroleum jelly + oil + alcohol on the tick before removal + heat (lighter) → these methods cause regurgitation of the tick's intestinal contents and increase the risk of transmission
- Technology: grasp the tick as close as possible to the skin with the fine forceps + pull firmly and gradually upwards (perpendicular to the skin) without turning + without crushing → extract the tick in a single movement
- After removal : disinfect the site with alcohol 70 % or soap and water + note the date of removal + keep the tick in an airtight bag or jar of alcohol for possible identification + monitor the site and general condition for 30 days
- Tick identification and submission: some provinces (including Quebec) offer tick surveillance programs → submit tick to public health laboratory for species identification + infection test → results guide therapeutic decision
Lyme disease - clinical stages
- Stage 1 - Early localized Lyme (J3-J30 after the bite) : erythema migrans (EM) = pathognomonic skin lesion present in 70-80 % of cases → expansive erythematous macule or plaque (> 5 cm) + centrifugal + with or without clear center (target appearance - present in only 20-30 % of cases) + from bite site + painless + non-itchy + lasts 3-4 weeks without treatment + associated symptoms: low-grade fever + headache + myalgias + arthralgias + fatigue
- Stage 2 - Early disseminated Lyme (weeks to months) : multiple erythema migrans (hematogenous dissemination) + early neuroborreliosis (lymphocytic meningitis + peripheral facial paralysis - unilateral or bilateral + painful radiculopathy + cranial nerve neuropathy) + Lyme carditis (1st to 3rd degree AVB + high degree AVB → temporary pacemaker if symptomatic)
- Stage 3 - Late Lyme (months to years) : Lyme arthritis (intermittent then persistent oligoarticular arthritis + knee +++ + large joint + effusion) + late neuroborreliosis (encephalopathy + polyneuropathy) + chronic atrophic acrodermatitis (CAA - atrophic purplish skin + limbs + Europe especially)
- Post-treatment symptoms of Lyme disease (PTLDS) : fatigue + pain + cognitive impairment persisting > 6 months after adequate and documented treatment + uncertain mechanism (no proven persistent active infection) + do not prolong antibiotics (no proven benefit + risks)
Diagnosis of Lyme disease
- Typical erythema migrans : sufficient clinical diagnosis → initiate antibiotic treatment WITHOUT waiting for serology (serology is often negative in early stages)
- Serology (two-level algorithm - Health Canada + CDC) : ELISA (Borrelia IgM + IgG) → if positive or doubtful → confirmatory Western blot + sensitivity 50-60 % in early stages + 95-99 % in late stages + false positives are possible (lupus + NID + syphilis + other spirochetes)
- PCR : useful in synovial fluid (Lyme arthritis - sensitivity 80 %) + or CSF (neuroborreliosis) + not very useful in blood
- NFS : leukopenia + thrombocytopenia + elevated transaminases in concomitant anaplasmosis (frequent co-infection in endemic areas)
Treatment - antibiotics according to stage
| Indication | Treatment of choice | Duration |
|---|---|---|
| Post-exposure prophylaxis (I. scapularis tick fixed ≥ 36 h in endemic areas) | Doxycycline 200 mg single dose PO | Single dose (within 72 h of tick removal) → reduced risk of 87 % |
| Erythema migrans (Lyme stage 1) | Doxycycline 100 mg × 2/d PO + or amoxicillin 500 mg × 3/d PO + or cefuroxime 500 mg × 2/d PO | 10-14 days (doxycycline) + 14-21 days (amoxicillin + cefuroxime) |
| Early neuroborreliosis (isolated facial paralysis) | Doxycycline 100 mg × 2/d PO | 14-21 days |
| Severe neuroborreliosis (meningitis + encephalitis) | Ceftriaxone 2 g IV × 1/d | 14-21 days |
| Lyme carditis (mild BAV) | Doxycycline 100 mg × 2/d PO | 14-21 days + cardiac monitoring |
| Severe Lyme carditis (high-grade AVB) | Ceftriaxone 2 g IV × 1/d | 14-21 days + temporary pacemaker if BAV ≥ 2nd degree symptomatic |
| Lyme arthritis | Doxycycline 100 mg × 2/d PO + or amoxicillin 500 mg × 3/d | 28 days + if persistent → ceftriaxone IV 28 days |
| Anaplasmosis / Ehrlichiosis | Doxycycline 100 mg × 2/d PO | 10-14 days |
| Mild to moderate Babesiosis | Atovaquone 750 mg × 2/d + azithromycin 500 mg D1 then 250 mg/d | 7-10 days |
Tick bite prevention in Quebec
- Skin repellents : DEET 20-30 % (adults + children > 6 months) → 4-8 h protection + icaridin 20 % (well-tolerated alternative + low odour) + permethrin on clothing (residual insecticide → several weeks protection)
- Protective clothing : long sleeves + long pants + tuck trouser bottoms into socks + closed-toe shoes → reduce access to areas of exposed skin
- Systematic skin inspection : after any activity in a wooded or grassy environment → inspect the entire body + insist on: scalp + ears + neck + armpits + umbilical region + groin + genital region + popliteal fossae + space between toes → have a close relative inspect non-visible areas
- Post-hike shower : within 2 hours of activity → reduced risk of undetected bites
- Drying clothes : 10 min at high temperature (≥ 60 °C) after hiking → kills ticks on clothing
- Pets : check and treat dogs + cats for ticks (veterinary antiparasitics) → pets can bring ticks into the house
Seek medical attention within 72 hours if a tick Ixodes scapularis remained fixed ≥ 36 hours in endemic areas of Quebec (Montérégie + Eastern Townships + other high-risk regions) to assess the indication for prophylaxis with single-dose doxycycline 200 mg. Consult a physician if a red, expansive skin lesion appears at the site of a tick bite within 3 to 30 days - even without a clear center. Seek emergency care if high fever + facial paralysis + palpitations + or difficulty walking occur in the weeks following a tick bite. For proper tick removal + post-exposure prophylaxis + diagnosis and treatment of Lyme disease, Clinique Omicron offers consultations at its points of service in Quebec and via telemedicine. To book an appointment, visit cliniqueomicron.ca.
Consult at Clinique Omicron
Clinique Omicron's specialized physicians and nurse practitioners (IPS) assess tick bites and the indication for post-exposure prophylaxis with doxycycline, diagnose Lyme disease by erythema migrans (treatment without waiting for serology) or by serology at later stages, treat Lyme disease and co-infections (anaplasmosis + babesiosis) according to clinical stage, refer to emergency or infectious diseases departments for severe forms (neuroborreliosis + carditis), and provide advice on preventing tick bites. Consultations are available at several points of service in Quebec, and via telemedicine. To book an appointment, visit cliniqueomicron.ca.
The contents of this page are provided for information purposes only and do not replace medical advice. Tick distribution Ixodes scapularis and prevalence of Lyme disease in Quebec are evolving rapidly with climate change - consult regional surveillance data from the Direction régionale de santé publique for the most up-to-date endemic areas. Lyme serology is falsely negative in the first 2 to 4 weeks - do not exclude the diagnosis on early negative serology if erythema migrans is present.
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