whipworm

Whipworm
Male Whipworm
Scientific classification
Kingdom:	Animalia
Phylum:	Nematoda
Class:	Adenophorea
Order:	Trichurida
Family:	Trichuridae
Genus:	Trichuris
Species:	T. trichiura
Binomial name
Trichuris trichiura (Linnaeus, 1771)

The human whipworm (Trichuris trichiura or Trichocephalus trichiuris), is a roundworm, which causes trichuriasis when it infects a human large intestine. The name whipworm refers to the shape of the worm; they look like whips with wider "handles" at the posterior end.

Life Cycle

The female T. trichiura produces 2,000–10,000 single celled eggs per day ^[1]. Eggs are deposited from human feces to soil where after 2 to 3 weeks, they become embryonated and enter the “infective” stage. These embryonated infective eggs are ingested and hatch in the human small intestine. This is the location of growth and molting. The infective larvae penetrate the villi and continue to develop in the small intestine. The young worms move to the cecum and penetrate the mucosa and there they complete development to adult worms in the large intestine. The life cycle from time of ingestion of eggs to development of mature worms takes approximately 3 months. During this time there may be limited signs of infection in stool samples due to lack of egg production and shedding. The female T. trichiura begin to lay eggs after 3 months of maturity. Worms can live up to 5 years where females can lay up to 20,000 eggs per day.

Recent studies using genome-wide scan revealed two quantitative trait loci on chromosome 9 and chromosome 18 may be responsible for genetic predisposition or susceptibility to infection of T. trichiura by some individuals.

Morphology

Trichuris trichiura has a narrow anterior esophageal end and shorter and thicker posterior anus. These pinkish-white worms are threaded through the mucosa. They attach to the host through their slender anterior end and feed on tissue secretions instead of blood. Females are larger than males; approximately 35–50 mm long compared to 30–45 mm respectively ^[2]. The females have a bluntly round posterior end compared to their male counterparts with a coiled posterior end. Their characteristic eggs are barrel-shaped, brown, and have bipolar protuberances.

Epidemiology

There is a worldwide distribution of Trichuris trichiura, with about 500 million human infections ^[3]. However, it is chiefly tropical, especially in Asia and to a lesser degree, in Africa and South America. Within the United States, infection is rare overall but may be common in the rural Southeast where 2.2 million people are thought to be infected. Poor hygiene is associated with Trichuriasis as well as the consumption of shaded moist soil, or food that may have been fecally contaminated. Children are especially vulnerable to infection due to their high exposure risk. Eggs are infective about 2–3 weeks after they are deposited in the soil under proper conditions of warmth and moisture, hence its tropical distribution.

Infection

Infection occurs through accidental ingestion of eggs (which are usually found in dry goods such as beans, rice, and various grains) and is more common in warmer areas. The eggs hatch in the small intestine, and then move into the wall of the small intestine and develop. On reaching adulthood, the thinner end (the front of the worm) burrows into the large intestine and the thicker end hangs into the lumen and mates with nearby worms. The females can grow to 50 mm (2 inches) long. Neither the male nor the female has much of a visible tail past the anus ^[1].

Whipworm commonly infects patients also infected with Giardia, Entamoeba histolytica, Ascaris lumbricoides, and hookworms.

Symptoms and Pathology

• Light infestations (<100 worms) are frequently asymptomatic.
• Heavy infestations may have bloody diarrhea.
• Long-standing blood loss may lead to iron-deficiency anemia.
• Rectal prolapse is possible in severe cases.
• Vitamin A deficiency may also result due to infection ^[2].

Mechanical damage to the mucosa may occur as well as toxic or inflammatory damage to the intestines of the host.

Diagnosis

Trichuriasis can be diagnosed when T. trichiura eggs are detected in stool examination. Eggs will appear barrel shaped, unembryonated, have bipolar plugs and a smooth shell ^[4].

Treatment and Control

Mebendazole is 90% effective in the first dose, and albendazole may also be offered as an anti-parasitic agent. Adding iron to the bloodstream helps solve the iron deficiency and rectal prolapse.

Infection can be avoided by proper disposal of human feces, avoiding fecal contamination of food, not eating dirt, and avoiding crops fertilized with night soil. Simple and effective proper hygiene such as washing hands and food is recommended for control.

Dog and cat whipworms

Egg of Trichuris vulpis

Egg of Trichuris vulpis

Whipworms develop when a dog swallows whipworm eggs, passed from an infected dog. Symptoms may include diarrhea, anemia, and dehydration. The dog whipworm (Trichuris vulpis) is commonly found in the U.S. It is hard to detect at times, because the numbers of eggs shed are low, and they are shed in waves. Centrifugation is the preferred method. There are several preventives available by prescription from a veterinarian to prevent dogs from getting whipworm.

The cat whipworm is a rare parasite. In Europe it is mostly represented by Trichuris campanula, and in North America it is Trichuris serrata more often.^[5][6] Whipworm eggs found in cats in North America must be differentiated from lungworms, and from mouse whipworm eggs just passing through.

Whipworm as a therapeutic agent for IBD and other inflammatory disorders

The Hygiene hypothesis suggests that various immunological disorders that have only been observed in humans, such as Crohn's Disease, within the last 100 years, or that have become more common during that time period as hygienic practices have become more widespread, may result from a lack of exposure to helminths. The use of Trichuris Suis Ova (TSO, or pig whipworm eggs) by Weinstock, et al., as a safe and effective therapy for treating Crohn's Disease^[7][8][9] and to a lesser extent Ulcerative Colitis are just two of many examples of this. There is also anecdotal evidence that those using TSO to treat IBD experience a decrease in asthma,^[10] allergy^[11] and other symptoms of inflammatory disorders. There is some scientific evidence to suggest that the course of Multiple Sclerosis may be very favorably altered by helminth infection,^[12] and Trichuris Suis Ova is currently being studied as a treatment for Multiple Sclerosis^[13]

See also

• Human parasitic diseases
• Helminthic therapy
• List of parasites (human)
• Worm

References

^{[1] [2] [14] [15]}

1. ^ ^{a b c} Books. "Trichuris Trichura". Ncbi.nlm.nih.gov. http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mmed.section.4814. Retrieved 2009-05-19. 
2. ^ ^{a b c} "Trichuris trichiura definition - Medical Dictionary definitions of popular medical terms easily defined on MedTerms". Medterms.com. 2000-04-15. http://www.medterms.com/script/main/art.asp?articlekey=12961. Retrieved 2009-05-19. 
3. ^ "Trichuris trichiura". WrongDiagnosis.com. 2009-05-06. http://www.wrongdiagnosis.com/medical/trichuris_trichiura.htm. Retrieved 2009-05-19. 
4. ^ "Trichuris trichiura". WrongDiagnosis.com. 2009-05-06. http://www.wrongdiagnosis.com/medical/trichuris_trichiura.htm. Retrieved 2009-05-19. 
5. ^ "Whipworms - VeterinaryPartner.com - a VIN company!". VeterinaryPartner.com. http://www.veterinarypartner.com/Content.plx?P=A&A=1668. Retrieved 2009-05-19. 
6. ^ Hendrix CM, Blagburn BL, Lindsay DS (1987). "Whipworms and intestinal threadworms". Vet. Clin. North Am. Small Anim. Pract. 17 (6): 1355–75. PMID 3328393. 
7. ^ Hunter MM, McKay DM (2004). "Review article: helminths as therapeutic agents for inflammatory bowel disease". Aliment. Pharmacol. Ther. 19 (2): 167–77. doi:10.1111/j.0269-2813.2004.01803.x. PMID 14723608. 
8. ^ Summers RW, Elliott DE, Urban JF, Thompson R, Weinstock JV (2005). "Trichuris suis therapy in Crohn's disease". Gut 54 (1): 87–90. doi:10.1136/gut.2004.041749. PMID 15591509. 
9. ^ Summers RW, Elliott DE, Qadir K, Urban JF, Thompson R, Weinstock JV (2003). "Trichuris suis seems to be safe and possibly effective in the treatment of inflammatory bowel disease". Am. J. Gastroenterol. 98 (9): 2034–41. doi:10.1111/j.1572-0241.2003.07660.x. PMID 14499784. 
10. ^ "Helminthic Therapy: How to put your Asthma, Colitis, IBD, Crohn's or Multiple Sclerosis into remission with hookworm". Asthmahookworm.com. http://www.asthmahookworm.com. Retrieved 2009-05-19. 
11. ^ "Allergies: Trichuris suis Ova (TSO) Therapy to Treat Food Allergies". Allergizer.com. http://www.allergizer.com/50226711/trichuris_suis_ova_tso_therapy_to_treat_food_allergies.php. Retrieved 2009-05-19. 
12. ^ Correale J, Farez M. (2007). "Association between parasite infection and immune responses in multiple sclerosis". Annals of Neurology 61 (2): 97–108. doi:10.1002/ana.21067. PMID 17230481. 
13. ^ "Asphelia Announces Initiation of An Independent TSO Trial for Multiple Sclerosis - Health News". redOrbit. 2008-04-07. http://www.redorbit.com/news/health/1329983/asphelia_announces_initiation_of_an_independent_tso_trial_for_multiple/index.html. Retrieved 2009-05-19. 
14. ^ "Trichuris Trichiura: eMedicine Emergency Medicine". Emedicine.medscape.com. 2009-05-05. http://emedicine.medscape.com/article/788570-overview. Retrieved 2009-05-19. 
15. ^ "Trichuris trichiura". WrongDiagnosis.com. 2009-05-06. http://www.wrongdiagnosis.com/medical/trichuris_trichiura.htm. Retrieved 2009-05-19. 

External links

Wikimedia Commons has media related to: Whipworm

• Potential Disease Treatment: Swallow Some Worms
• Globe and Mail: Sometimes having worms is good
• BBC article mentions the Iceman had Whipworm
• Video of Live Trichuris trichiura "Whip Worm"

The Iceman had the whipworm when he was in the Alps Mountains and thats a theory of how he died.