Trichocéphalose (Whipworm)

Cycle biologique et épidémiologie

• Hôte : exclusively human (anthroponosis) + no animal reservoir for Trichuris trichiura human (unlike *T. vulpis* of the dog)
• Cycle: eggs excreted in patient's stool → maturation in warm, moist soil (≥ 3–6 weeks + temperature ≥ 25 °C + high humidity) → ingestion of infective embryonated eggs → hatching in small intestine → migration to cecum + ascending colon → implantation of anterior end in mucosa → adult worm (lifespan 1–3 years) → laying of 2,000–10,000 eggs/day by female
• Répartition géographique : intertropical and subtropical zones with poor sanitation → sub-Saharan Africa + Southeast Asia + Caribbean + Central and South America + Indian subcontinent + prevalence up to 90% % in some pediatric populations in endemic areas
• Risk factors: lack of toilets + open defecation + use of human feces as fertilizer (agricultural practice) + consumption of unwashed contaminated vegetables or fruits + children playing in contaminated soil

Présentation clinique selon la charge parasitaire

• Infection légère (faible charge — <100 vers) : Asymptomatic in most cases + incidental finding on a stool parasitology exam + or moderate eosinophilia on a complete blood count
• Infection modérée (100–1 000 vers) : Abdominal pain + cramps + loose stools or intermittent diarrhea + flatulence + nausea + fatigue + pain in the right iliac fossa (frequent – cecal localization of worms → can mimic appendicitis)
• Infection sévère (syndrome dysentériforme — >1 000 vers — enfant surtout) : Chronic muco-purulent bloody diarrhea + tenesmus + erosive colitis + iron deficiency anemia (chronic mucosal bleeding) + hypoalbuminemia + growth retardation + cognitive delay (anemia + chronic malnutrition) + significant eosinophilia
• Rectal prolapse: Severe complication of very heavy infections in a child + luxuriant rectal mucosa teeming with whipworms prolapsing through the anus → one can visualize the white worms attached to the prolapsed mucosa → manual reduction of the prolapse + urgent antiparasitic treatment
• Éosinophilie : often present (NFS — 5–15 % eosinophils) + useful for suggesting the diagnosis in an asymptomatic patient returning from a tropical area

Diagnosis

• Stool parasitological examination (SPE) reference method + identification of characteristic eggs in «lemon» or «barrel» with clear polar plugs at both ends + dimensions: 50 × 22 µm → very recognizable + Kato-Katz method (concentration + quantification) to assess parasitic load
• Nombre de selles à examiner : at least 3 samples on different days to optimize sensitivity (eggs may be absent on certain days → successive examinations)
• NFS : éosinophilie (hyperéosinophilie souvent > 500/µL) + anémie si infection lourde + hypoalbuminémie dans les formes sévères chroniques
• Colonoscopy can directly visualize adult worms embedded in the mucosa of the cecum + colon + characteristic «whip-like» appearance of the worm with a thickened posterior end in the lumen + rarely necessary for diagnosis but possible during a colonoscopy done for another indication
• Serology not available for routine use + not clinically useful

Anti-parasite treatment

Prévention et mesures d'hygiène

• Careful hand washing: after contact with the ground + before meals + after using the toilet → most effective measure for individual prevention
• Lavage des fruits et légumes : especially those grown in potentially contaminated soils (market gardening with organic fertilizers) + peel fruits if possible
• Drinking water drink filtered or boiled water in at-risk areas
• Traitement de masse (MDA — Mass Drug Administration) : WHO annual mass deworming programs in schools in endemic countries + albendazole or mebendazole in annual single dose + significant reduction in prevalence and intensity of infection
• Amélioration des installations sanitaires : Access to latrines + wastewater treatment + ban on using human feces as fertilizer → essential long-term infrastructure measures

Consult at Clinique Omicron

Les médecins et infirmiers praticiens spécialisés (IPS) de Clinique Omicron prescrivent l'examen parasitologique des selles (3 prélèvements) chez les voyageurs de retour de zones tropicales avec symptômes digestifs ou éosinophilie, diagnostiquent la trichocéphalose par identification des œufs en barrique caractéristiques, prescrivent l'albendazole 400 mg × 3 jours ou la combinaison albendazole + ivermectine selon la sévérité, et assurent le bilan post-traitement. Des consultations sont disponibles dans plusieurs points de service au Québec et en télémédecine. Pour prendre rendez-vous, visitez cliniqueomicron.ca.

Le contenu de cette page est fourni à titre informatif uniquement et ne remplace pas l'avis d'un médecin ou d'un infectiologue. L'examen parasitologique des selles nécessite au minimum 3 prélèvements à des jours différents pour une sensibilité optimale — un examen négatif unique n'exclut pas le diagnostic. L'ivermectine est contre-indiquée en grossesse et chez l'enfant de moins de 15 kg.