Infectiology - Food poisoning - Notifiable diseases
Campylobactériose | Clinique Omicron Québec
Campylobacteriosis is a bacterial enteric infection caused mainly by Campylobacter jejuni and, in a smaller proportion of cases, by Campylobacter coli - two species of spiral- or comma-shaped microaerophilic Gram-negative bacilli belonging to the genus Campylobacter. It is the most common bacterial foodborne infection in industrialized countries, ahead of salmonellosis and Escherichia coli shigatoxin producers: in Canada, over 10,000 cases are reported annually to the Public Health Agency of Canada (PHAC), but estimates correcting for under-reporting suggest an actual number of cases 30 to 100 times higher, potentially infecting over a million Canadians each year. The main reservoir of Campylobacter is the intestinal tract of poultry - chickens, turkeys and ducks - which harbor the bacteria as commensals without developing disease; contamination of carcasses at slaughter is almost universal, so handling or eating raw or undercooked poultry is the most frequent route of exposure. The disease manifests itself as acute febrile gastroenteritis with diarrhea - often bloody, due to invasive colitis caused by C. jejuni - preceded by a prodromal period of 24 to 48 hours of fever, myalgias and intense abdominal cramps that may mimic acute appendicitis. In the vast majority of cases, campylobacteriosis is self-limiting in 5 to 10 days in immunocompetent subjects, requiring only oral rehydration and symptomatic treatment. Its clinical importance, however, lies in its potentially serious post-infectious complications: Guillain-Barré syndrome - an acute autoimmune polyneuropathy with the potential to paralyze. C. jejuni is the most common infectious trigger worldwide - and reactive arthritis (Reiter's syndrome). Campylobacteriosis is a notifiable disease in Quebec.
Microbiology and virulence factors
Campylobacter jejuni has several distinctive biological characteristics that explain its epidemiology and pathogenicity:
- Spiral or comma-shaped, Gram-negative bacillus, motile by one or two polar flagella conferring the characteristic corkscrew motility; strict microaerophile - requires an atmosphere of 5 % of O₂ and 10 % of CO₂ to grow, which complicates its isolation by standard bacteriological methods and explains why special selective media and incubation at 42°C (instead of the usual 37°C) are required for its culture in the laboratory
- Characteristic thermophilicity: optimal growth at 42°C (intestinal temperature of poultry) and rapid inactivation at temperatures above 60°C - which explains why sufficient cooking of poultry (internal temperature ≥ 74°C) effectively destroys the bacterium, and why refrigeration (4°C) does not eliminate it but slows down its multiplication
- Very low infectious dose: less than 500 bacteria are enough to cause infection in humans, which explains why transmission is possible through simple cross-contamination of surfaces or cooking utensils, without direct ingestion of the bacteria.
- Virulence factors: flagella (mobility, invasion of intestinal mucosa); CiaB invasion proteins enabling penetration of epithelial cells; cytolethal distending toxin (CDT) inducing DNA damage and cell death; membrane lipooligosaccharide (LOS) mimicking human nerve gangliosides GM1, GD1a and GQ1b - mechanism of molecular mimicry at the origin of post-infectious Guillain-Barré syndrome.
Epidemiology and sources of contamination
Campylobacteriosis has a seasonal epidemiology and well-characterized transmission routes:
- Marked summer seasonality in Canada and Quebec: peak incidence between June and September, coinciding with increased outdoor dining, barbecuing and handling of raw poultry; second small peak at the end of the year associated with holiday meals involving poultry
- Main route of contamination - undercooked poultry or improper handling: raw chicken is contaminated by C. jejuni in 50 to 80 % of cases in Canadian grocery stores; cross-contamination of vegetables or ready-to-eat foods by raw chicken juice on the worktop or kitchen utensils is a frequent and underestimated cause
- Untreated drinking water: community epidemics linked to drinking water systems contaminated by animal faeces (private wells, springs in rural areas); Quebec municipalities with chlorine treatment are protected because C. jejuni is sensitive to residual chlorine
- Unpasteurized raw milk: source of documented epidemics in Canada associated with consumption of unpasteurized farm milk
- Contact with pets: puppies and kittens are a major reservoir - a puppy with diarrhoea is a carrier of Campylobacter in 20 to 40 % of cases; transmission by direct or indirect contact with animal faeces
- Travelers returning from countries with poor food hygiene (traveler's diarrhea): C. jejuni and C. coli are among the most common agents of traveler's diarrhea in Southeast Asia, Africa and Latin America.
- Direct human-to-human transmission: possible but rare in immunocompetent adults due to the high dose of infection required by the direct faecal-oral route; more frequent in day-care centres among young children in labour.
Clinical presentation
The classic clinical picture of campylobacteriosis evolves in successive phases:
| Phase | Duration | Events |
|---|---|---|
| Incubation | 1 to 7 days (median 2 to 3 days) | Asymptomatic; incubation period depends on ingested dose and host immunity; shorter for high doses |
| Prodrome | 12 to 48 hours | High fever (38.5 to 40°C), chills, diffuse myalgias, headaches, general malaise; abdominal cramps around the umbilicus or in the right iliac fossa, sometimes very intense, may mimic acute appendicitis or Crohn's disease in flare-up - unnecessary exploratory laparotomies have been performed at this stage before the diagnosis was identified |
| Acute diarrhea phase | 3 to 7 days (sometimes up to 10 days) | Watery diarrhea, then rapidly hemorrhagic in 50 to 70 % of cases (bright red blood or melena); 5 to 10 liquid or semi-liquid stools per day; persistent intense abdominal cramps often synchronous with stools; frequent tenesmus; nausea and vomiting in 30 to 50 % of cases (rarely in the foreground, unlike viral gastroenteritis); fever gradually decreases during this phase. |
| Convalescence | 1 to 2 weeks | Progressive normalization of bowel movements; residual asthenia is common for 1 to 2 weeks after clinical recovery; fecal excretion of the bacteria may persist for 2 to 4 weeks after resolution of symptoms. |
ℹ️
Intense abdominal pain in the right iliac fossa at the onset of campylobacteriosis may be clinically indistinguishable from acute appendicitis, sometimes leading to unnecessary surgery. Evidence of an exposure context (recent chicken meal, travel) and the concomitant or subsequent appearance of febrile diarrhea should raise the diagnosis and lead to a coproculture prior to any surgical decision in the absence of frank peritoneal syndrome.
Biological diagnosis
The diagnosis of campylobacteriosis is based on microbiological examinations of stools:
- Coproculture on selective media for Campylobacter (Skirrow medium, CCDA medium or charcoal-blood agar) with incubation at 42°C in a microaerophilic atmosphere for 48 to 72 hours; sensitivity of 85 to 95 % if sample taken within the first 4 days of symptoms; results within 48 to 72 hours; reference method for antibiogram and speciation (C. jejuni vs. C. coli)
- Stool multiplex PCR (gastroenteritis panel): a method increasingly available in Quebec hospital laboratories, allowing simultaneous detection of the main agents of bacterial gastroenteritis (Campylobacter, Salmonella, Shigella, E. coli O157, C. difficile) and viral (norovirus, rotavirus) in less than 4 hours; higher sensitivity than culture (95 to 99 %); disadvantage: does not provide an antibiogram
- CBC: leukocytosis with moderate neutrophilic polynucleosis (10 to 15 G/L); a very high count or the presence of immature forms should suggest bacteremia or a complication.
- Blood cultures: indicated if persistent very high fever or signs of sepsis; bacteremia in Campylobacter is rare (less than 1 % of cases) but may occur in immunocompromised patients (HIV, haematological malignancies) or at extreme ages; standard blood cultures may fail to detect Campylobacter if the laboratory is not notified of the suspected diagnosis
- Sigmoidoscopy or colonoscopy: not routinely indicated in acute gastroenteritis, but can reveal diffuse or segmental hemorrhagic colitis that may mimic inflammatory bowel disease in flare-ups; reserved for prolonged or atypical forms after resolution of the acute episode
Treatment
The vast majority of campylobacteriosis cases heal spontaneously without antibiotic treatment. Treatment is mainly symptomatic:
| Therapeutic aspect | Recommendation | Details |
|---|---|---|
| Oral rehydration | Basic treatment for all patients | Commercial or prepared oral rehydration solutions (ORS) (1 liter of water + 6 teaspoons of sugar + ½ teaspoon of salt); isotonic sports drinks acceptable in adults; water alone insufficient to compensate for electrolyte losses; IV rehydration if severe dehydration or vomiting prevents oral rehydration |
| Symptomatic treatment of pain and fever | Paracetamol or ibuprofen | NSAIDs can aggravate intestinal lesions in some infectious colitis - use with caution; loperamide (transit retardant) is not recommended in febrile bloody diarrhea, due to the theoretical risk of prolonging infection |
| Antibiotic therapy - indications | Reserved for severe forms or at-risk patients | Indicated in cases of: profuse bloody diarrhea with severe dehydration; persistent very high fever (≥ 39°C > 3 days); severe symptoms > 7 days without improvement; confirmed bacteremia; immunosuppression (HIV, chemotherapy, long-term corticosteroid therapy, transplantation); extreme ages (infant < 3 months, frail elderly); pregnancy. |
| Antibiotic therapy - first choice | Azithromycin 500 mg/day po × 3 days (adult); 10 mg/kg/day × 3 days (child) | Macrolide recommended by PHAC and INESSS as first-line treatment; efficacy shown to shorten the duration of symptoms by 1 to 2 days if started early; macrolide resistance rate in Canada remains low (5 to 10 % depending on the province) but on the rise; antibiotic susceptibility testing recommended to guide choice in case of failure or origin from a high-resistance area |
| Antibiotic therapy - alternative | Ciprofloxacin 500 mg twice daily × 3 to 5 days (adult) | To be avoided as first-line treatment in Canada due to the now high rate of fluoroquinolone resistance (30 to 50 % in imported travel strains, 15 to 25 % in local strains); to be reserved for cases confirmed as susceptible by susceptibility testing or as an alternative to macrolides in cases of documented allergy. |
| Bacteremia with Campylobacter | Imipenem or gentamicin IV according to antibiogram | Bacteremia is rare but serious, especially in immunocompromised patients; duration of IV treatment: 14 days minimum; oral relay with azithromycin depending on sensitivity. |
Post-infectious complications
Despite the usual resolution in less than two weeks, campylobacteriosis can be followed by late immunological complications, some of which are potentially serious:
- Guillain-Barré syndrome (GBS): acute demyelinating and/or axonal polyradiculoneuritis triggered by an autoimmune response targeting peripheral nerve myelin gangliosides through molecular mimicry with the lipooligosaccharide (LOS) from C. jejuni ; occurs 1 to 3 weeks after gastroenteritis in about 1 in 1,000 to 2,000 patients infected by C. jejuni ; C. jejuni is implicated in 25 to 40 % of all GBS cases worldwide - it is the most frequent infectious triggering cause; axonal forms of GBS (AMAN, AMSAN) are more often associated with C. jejuni than the classic demyelinating form and have a less favourable functional prognosis; treatment with IV immunoglobulins or plasma exchange; hospitalization and ventilatory monitoring essential.
- Reactive arthritis (Reiter's syndrome): aseptic inflammatory arthritis affecting large joints (knees, ankles, hips) occurring 1 to 3 weeks after digestive infection, sometimes accompanied by urethritis, conjunctivitis and skin lesions (gonorrhoeal keratoderma, circinate balanitis) forming the classic triad of Reiter's syndrome; more frequent in HLA-B27 antigen carriers; usually favorable evolution in a few months, but relapses possible; treatment with NSAIDs and corticosteroids.
- Post-infectious irritable bowel syndrome (PI-IBS): persistent impairment of intestinal motility and sensitivity after recovery from acute infection; chronic diarrhea, bloating and abdominal pain persisting for months to years; occurs in 5-15 % of patients after documented acute bacterial gastroenteritis at Campylobacter, Salmonella or E. coli O157
- Chronic enteritis in the immunocompromised: HIV-infected patients with CD4 lymphocytes below 100 cells/mm³ may develop chronic campylobacteriosis with persistent diarrhea, recurrent bacteremia and atypical disseminated forms requiring prolonged treatment.
Individual and collective prevention
Prevention is based on food and personal hygiene measures that are accessible to all:
- Sufficient cooking of poultry: reach an internal temperature of at least 74°C measured with a meat thermometer in the thickest part - correctly cooked chicken is white throughout, with no pink parts, and the cooking juices are clear; never eat pink or partially cooked chicken.
- Preventing cross-contamination in the kitchen: use separate cutting boards and utensils for raw poultry and other foods; never place ready-to-eat food on a surface that has been in contact with raw poultry without thorough cleaning first; wash hands with soap for at least 20 seconds immediately after handling raw poultry.
- Proper storage: store raw poultry in an airtight container at the bottom of the fridge to prevent juices from dripping onto other foods; never defrost poultry at room temperature.
- Avoid unpasteurized raw milk and dairy products; ensure eggs are thoroughly cooked
- Safe drinking water in rural areas: treat well or spring water by boiling (1 minute at full boil) or disinfecting with chlorine (sodium hypochlorite) if there is any doubt about microbiological quality; have private well water tested regularly
- Hygiene when in contact with animals: wash hands after contact with domestic poultry, puppies, kittens or any farm animal; do not kiss animals on the snout; supervise young children when visiting contact farms or zoos.
- Collective measures in the workplace or school: exclusion of sick people from professional kitchens and day-care centers for up to 48 hours after complete resolution of diarrhea and vomiting; reporting of cluster cases to the Direction régionale de santé publique (DRSP - regional public health department)
ℹ️
Campylobacteriosis is a reportable disease (MADO) in Quebec. Any case confirmed by culture or PCR must be reported by the laboratory and the attending physician to the Direction régionale de santé publique (DRSP) within 48 hours. Public health can then identify and investigate outbreak episodes (e.g. group meals, food establishments) and implement control measures to protect others. Food service and childcare workers who test positive should be excluded from the workplace until symptoms resolve.
Signs requiring urgent medical attention
Seek immediate medical attention or go to the emergency room if diarrhea is accompanied by signs of severe dehydration (very dry mouth, absence of urine for more than 8 hours, extreme weakness, confusion), abundant blood in the stools, fever over 39.5°C resistant to antipyretics, persistent severe abdominal pain, or if symptoms do not improve after 7 days. In infants under 3 months of age, any febrile diarrhea should be medically evaluated without delay. After a recent bout of gastroenteritis, if progressive muscle weakness of the upper or lower limbs, difficulty walking, or difficulty swallowing or breathing develop within 2 to 4 weeks, consult an emergency room immediately to rule out Guillain-Barré syndrome.
For evaluation of febrile gastroenteritis, prescription of a gastroenteritis coproculture or PCR panel, antibiotic treatment if indicated, or follow-up of post-infectious complications, Clinique Omicron offers medical consultations at its points of service on the South Shore, in Montreal and via telemedicine. To book an appointment, visit cliniqueomicron.ca.
Consult at Clinique Omicron
Clinique Omicron takes charge of evaluating bacterial gastroenteritis, prescribing microbiological tests, initiating antibiotic treatment when indicated, and reporting to public health in accordance with Quebec legal obligations, at its 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 the advice of a qualified healthcare professional. Consult a physician for any febrile bloody diarrhea, symptoms persisting beyond 7 days, or neurological signs appearing in the weeks following gastroenteritis.
Omicron Clinic
Need to consult a doctor?
Treatment within 24-48 hours. In-clinic or telemedicine, anywhere in Quebec.
Insurance receipts. 7j/7. No family doctor required.