Colon
Infectious colitis
Trichuriasis
Author: Elliot Weisenberg, M.D.
Last author update: 1 October 2016
Last staff update: 30 September 2020
Copyright: 2003-2024, PathologyOutlines.com, Inc.
PubMed Search: Trichuriasis colitis
Table of Contents
Definition / general | Essential features | ICD coding | Epidemiology | Sites | Pathophysiology | Diagrams / tables | Clinical features | Diagnosis | Laboratory | Prognostic factors | Case reports | Treatment | Clinical images | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Differential diagnosis | Additional referencesCite this page: Weisenberg E. Trichuriasis. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/colontrichuriasis.html. Accessed December 30th, 2024.
Definition / general
- Colonic infection with the nematode Trichuris trichiura (whipworm)
Essential features
- Infection via the fecal oral route
- More common in children
- Symptoms vary from none / mild to abdominal pain, diarrhea, growth retardation, anemia and others in children
ICD coding
- B79
Epidemiology
- The CDC estimates that 604 to 795 million people are infected worldwide
- Disease more common in children
- Infection via the fecal oral route and correlates with poor sanitation and poverty
- Infection most common in the tropics where human feces is used as fertilizer or where open defecation occurs
- May also be common in temperate zones during warm and humid weather
- Infection may occur via ingesting eggs in contaminated soil via hands, as commonly occurs in children or eating contaminated, inadequately cleaned fruits or vegetables
- Genetic factors likely impact susceptibility to infection
- Disease is uncommon in the United States but is found occasionally in the Southeast
- Incidence of infection is decreasing with globally improved sanitation
Sites
- Worms usually reside in the cecum and ascending colon
- More distal colon may be involved with more severe infection
- No migratory phase through the lungs
Pathophysiology
- Excreted eggs become embryonated and infective in 15 to 30 days after passing through a 2 cell stage
- Embryonated eggs are ingested and the larvae hatch in the small intestine
- Larvae migrate to the cecum and ascending colon and penetrate crypts
- Worms molt several times and embed their whip-like anterior into mucosal crypts
- Females oviposit after two to three months
- Female egg output is high, 3000 to 20,000 eggs per day or about 200 eggs per gram of stool
- Worms live one to three years
- Worms do not invade but infection may lead to mucosal production of anti-inflammatory cytokines; this property has led to the controversial use of Trichuris suis to treat inflammatory bowel disease, although most authorities do not recommend this treatment
Diagrams / tables
Images hosted on other servers:
Life cycle
Clinical features
- Majority of carriers are asymptomatic or minimally symptomatic
- Peripheral blood eosinophilia may occur
- More severe disease tends to occur in children who often have higher parasite burdens and lesser immunity
- Heavy infections may be associated with chronic abdominal pain, diarrhea, tenesmus, chronic anemia, nocturnal incontinence, growth retardation that may be due in part to vitamin A deficiency and rectal prolapse
- Patients may also suffer from other parasitic infections
Diagnosis
- Diagnosis is made by seeing worms on mucosal surfaces or by identifying the characteristic lemon shaped eggs in stool
- Stool examination has a very high yield due to high egg output
Laboratory
- Eggs are 50 - 55 × 20 - 25 micrometers and have a characteristic barrel shape with thick shells and polar plugs at each end
Prognostic factors
- Disease is more severe in children
- Infection clears in essentially all patients with appropriate treatment
Case reports
- 8 year old boy with massive infection causing bloody diarrhea (J Trop Pediatr 2006;52:66)
- 48 year old man believed to have colon cancer treated with removal of the worms during colonoscopy (Int J Infect Dis 2013;17:e1073)
- Middle aged woman with tuberculosis, asthma and chronic diarrhea, detected during colonoscopy (J Pak Med Assoc 2014;64:1438)
- 84 year old woman with dyspnea, heart failure and severe anemia with concurrent Necator americanus and Ascaris lumbricoides (Endoscopy 2014;46 Suppl 1 UCTN:E117)
Treatment
- Three to seven day courses of albendazole, mebendazole or ivermectin, depending on the severity of the infection
Clinical images
Images hosted on other servers:
Endoscopic image of adult worm
Gross description
- Worms display a characteristic shape with a slender whip-like anterior that embeds in the colonic mucosa and a thicker posterior that is visible during endoscopy or on the surface of prolapsed rectal mucosa
- Adult worms are about 4 cm in length
Gross images
Images hosted on other servers:
Adult T. trichiura removed during a colonoscopy
Infestation with mucosal hemorrhage
Microscopic (histologic) description
- Mucosa in the vicinity of embedded worms is edematous and friable with increased histiocytes within the laminal propria
Microscopic (histologic) images
Images hosted on other servers:
Ova stained with iodine
Differential diagnosis
- The appearance of the adult worm and egg are essentially pathognomonic
- Clinically may mimic inflammatory bowel disease, other parasitic infections, appendicitis, bacterial or viral gastroenteritis
