AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Background

Trichuris trichiura (whipworm) is a roundworm of the phylum Nematoda. It is one of the most common human parasites. The common name is derived from the worm's distinctive whiplike shape. The adult worm usually reaches 3-5 cm in length and has a lifespan of 1-3 years.

Pathophysiology

Humans are the only known host of T trichiura. The organism is spread via the fecal-oral route. Potential hosts ingest the embryonated (mature) eggs. The eggs hatch in the small intestine, and the larvae attach to and penetrate the small intestinal mucosa, where they begin to mature. After approximately one week, the immature worms move passively to the large intestine and proximal colon. The worms' anterior portions penetrate the mucosal epithelium and the worms can imbed over one half of their length into the mucosal surface.

Once the worms are sexually mature, mating begins. Egg production occurs 2-3 months after initial ingestion. The female worm is capable of producing 3,000-20,000 eggs a day. Once the eggs are passed in the feces, they develop in a warm humid environment. Egg maturation occurs in approximately 2-6 weeks. The embryonated egg can maintain viability for several months under suitable conditions. Destruction occurs with exposure to direct sunlight for more than 12 hours and to temperatures of less than -8°C or higher than 40°C for one hour.

Frequency

United States

Prevalence of whipworm infestation is less than 0.1%. The most common areas of infection are the southern Appalachian range and Gulf coast states.¹

International

Whipworm infections are among the most common of all human parasites, with an estimated 750-800 million infections worldwide. The most affected regions are rural areas with poor sanitation and tropical climates, including Southeast Asia, Africa, the Caribbean, and Central and South America. Prevalence rates are as high as 80% in these regions. In contrast, prevalence in areas of Western Europe and Japan is similar to that in the United States.

Mortality/Morbidity

Most infections are asymptomatic. Symptoms are related to the worm load or number of worms involved in an infection. Heavy infections (hundreds to thousands of worms) can lead to death secondary to GI and hematologic complications.

Age

Although infections are observed in all age groups, most heavy infections are observed in the pediatric population. This probably reflects the increased likelihood of children to have poor hygiene and to play in soil that carries the worms' mature eggs.

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

History

• When evaluating a patient suspected of having a whipworm infection, the most important part of the history is travel to or living in an area of known infestation.
• GI complaints associated with these infections are diverse. Long-term GI complaints with associated exposure suggest whipworm infection.
• Most infections are asymptomatic. Patients with fewer than 100 worms are frequently asymptomatic; however, they may present with lower abdominal discomfort, flatulence, and diarrhea or constipation.
• Patients with heavy infection have hundreds to thousands of worms and may present with lower or epigastric pain, vomiting, abdominal distension, anorexia, weight loss, anemia, diarrhea, tenesmus (painful straining), and rectal prolapse. Trichuris dysentery syndrome is observed in heavy infections and characterized by bloody mucoid diarrhea, small frequent stools, tenesmus, anemia, and growth retardation.
• Polyparasitic infections can occur with whipworms, ascaris, and hookworms because these parasites live in similar environments.²

Physical

• Generally, physical examination findings are normal.
• Each worm causes an estimated 5 µL of blood loss every day.
• Heavy infections are required to cause anemia.
• Prolonged infections are reported to lead to growth failure, intellectual delays, and digital clubbing; however, growth and intellectual delays are likely to be multifactorial.

Causes

• The organism is spread via the fecal-oral route. Potential hosts ingest the embryonated (mature) eggs.
• Most heavy infections are observed in the pediatric population because children are more likely to have poor hygiene and to play in soil that carries the worms' mature eggs.

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Other Problems to be Considered

Gastrointestinal bleeding
Intestinal duplications
Milk protein allergy
Eosinophilic colitis
Neglect
Malignancy
Atopy
Copper deficiency
Pediatrics, Rotavirus
Clostridium Difficile Colitis

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Lab Studies

• Diagnosis is usually established by means of microscopic examination of stool.
• • Whipworm eggs have a characteristic barrel (American football) shape with translucent polar plugs.
  • The stool commonly contains RBCs and WBCs, including eosinophils/Charcot-Leyden crystals.
• Perform a CBC count. Eosinophilia is uncommon; however, when present, it ranges from 5-20%.

Procedures

• Anoscopy may be useful. In heavy infections, worms can be directly visualized.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical Care

Infections are treated with broad-spectrum anthelminthic agents. Most infections can be treated successfully with mebendazole. Retreatment is occasionally necessary if symptoms persist longer than 2 weeks after initial treatment.

Consultations

Consultations with the following specialists may be appropriate:

• Infectious disease specialist
• Gastroenterologist 
• Hematologist

MEDICATION

Section 7 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Drug Category: Anthelmintics

Parasite biochemical pathways are different from the human host; thus, toxicity is directed to the parasite, egg, or larvae. Mebendazole is the treatment of choice for trichuriasis. Albendazole is an alternative medication that can be used.³ Both are broad-spectrum anthelminthic agents. These drugs interfere with the organism's microtubule formation. Recently, nitazoxanide has been studied as a possible treatment option.^{4, 5, 6}

FOLLOW-UP

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Further Outpatient Care

• Retreatment may be necessary if symptoms persist 2-3 weeks after initial therapy.

Deterrence/Prevention

• Limiting the morbidity associated with this disease centers around improved sanitation for areas with heavy infestation.
• Some clinicians have suggested periodic deworming programs for children in endemic areas.

Complications

• Rectal prolapse, dysentery, anemia, malnutrition, and growth retardation all can complicate heavy infections.

Prognosis

• With treatment, prognosis is typically excellent.

Patient Education

• Emphasize good hygiene and avoidance of pica.

MISCELLANEOUS

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical/Legal Pitfalls

• Failure to recognize the most severe infections as parasitic is a pitfall. Resultant delay in antiparasitic treatment can lead to morbidity associated with blood loss, malnutrition, and electrolyte imbalances.

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

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Article Last Updated: Mar 19, 2008