UpToDate
Official reprint from UpToDate®
www.uptodate.com ©2016 UpToDate®

Enterobiasis (pinworm) and trichuriasis (whipworm)

Authors
Karin Leder, MBBS, FRACP, PhD, MPH, DTMH
Peter F Weller, MD, FACP
Section Editor
Edward T Ryan, MD, DTMH
Deputy Editor
Elinor L Baron, MD, DTMH

INTRODUCTION

Enterobius vermicularis (pinworm) and Trichuris trichiura (whipworm) are two of the most common nematode infections worldwide [1].

ENTEROBIASIS (PINWORM)

Enterobiasis occurs in both temperate and tropical climates; it is the most common helminthic infection in the United States and Western Europe [2]. Prevalence estimates suggest there are 40 million infected persons in the United States [3].

Humans are the only natural host. Infection occurs in all socioeconomic groups; transmission is most efficient when people are living in closed, crowded conditions and is common within families. Enterobiasis is observed most frequently among school children aged 5 to 10 years; it is relatively uncommon in children <2 years old.

Life cycle and transmission — E. vermicularis has a simple life cycle (figure 1). The cycle begins with egg deposition by gravid adult female worms on the perianal folds. Autoinfection occurs by scratching the perianal area and transferring infective eggs to the mouth with contaminated hands. Person-to-person transmission can occur by eating food touched by contaminated hands or by handling contaminated clothes or bed linens. Infection may also be acquired via contact with environmental surfaces (curtains, carpeting) that are contaminated with eggs. In addition, eggs may become airborne, inhaled, and swallowed.

Following ingestion, eggs hatch and release larvae in the small intestine. The adult worms establish themselves in the gastrointestinal tract, mainly in the cecum and appendix. The time interval from ingestion of infective eggs to oviposition by the adult females is about one month. Each female worm can produce 10,000 or more eggs. The life span of the adults is two to three months. Most infected individuals have a few to several hundred adult worms. The worm burden is not distributed evenly among individuals; the one-quarter of the population that is most heavily infected has more than 90 percent of the total worm burden [4].

              

Subscribers log in here

To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information or to purchase a personal subscription, click below on the option that best describes you:
Literature review current through: Nov 2016. | This topic last updated: Tue Dec 22 00:00:00 GMT+00:00 2015.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use ©2016 UpToDate, Inc.
References
Top
  1. Bethony J, Brooker S, Albonico M, et al. Soil-transmitted helminth infections: ascariasis, trichuriasis, and hookworm. Lancet 2006; 367:1521.
  2. Moore TA, McCarthy JS. Enterobiasis. In: Tropical Infectious Diseases: Principles, Pathogens and Practice, 3rd ed, Guerrant R, Walker DH, Weller PF (Eds), Saunders Elsevier, Philadelphia 2011. p.788.
  3. Centers for Disease Control and Prevention. Enterobiasis (Enteroblus vermicularis) www.dpd.cdc.gov/DPDx/HTML/Enterobiasis.htm (Accessed on November 16, 2011).
  4. Maizels RM, Bundy DA, Selkirk ME, et al. Immunological modulation and evasion by helminth parasites in human populations. Nature 1993; 365:797.
  5. Jones JE. Pinworms. Am Fam Physician 1988; 38:159.
  6. Stĕrba J, Vlcek M. Appendiceal enterobiasis--its incidence and relationships to appendicitis. Folia Parasitol (Praha) 1984; 31:311.
  7. Wiebe BM. Appendicitis and Enterobius vermicularis. Scand J Gastroenterol 1991; 26:336.
  8. Grencis RK, Cooper ES. Enterobius, trichuris, capillaria, and hookworm including ancylostoma caninum. Gastroenterol Clin North Am 1996; 25:579.
  9. Arca MJ, Gates RL, Groner JI, et al. Clinical manifestations of appendiceal pinworms in children: an institutional experience and a review of the literature. Pediatr Surg Int 2004; 20:372.
  10. da Silva DF, da Silva RJ, da Silva MG, et al. Parasitic infection of the appendix as a cause of acute appendicitis. Parasitol Res 2007; 102:99.
  11. Liu LX, Chi J, Upton MP, Ash LR. Eosinophilic colitis associated with larvae of the pinworm Enterobius vermicularis. Lancet 1995; 346:410.
  12. Cacopardo B, Onorante A, Nigro L, et al. Eosinophilic ileocolitis by Enterobius vermicularis: a description of two rare cases. Ital J Gastroenterol Hepatol 1997; 29:51.
  13. Burkhart CN, Burkhart CG. Assessment of frequency, transmission, and genitourinary complications of enterobiasis (pinworms). Int J Dermatol 2005; 44:837.
  14. Vasudevan B, Rao BB, Das KN. Infestation of Enterobius vermicularis in the nasal mucosa of a 12 yr old boy--a case report. J Commun Dis 2003; 35:138.
  15. Drugs for Parasitic Infections, 3rd Ed, The Medical Letter, New Rochelle, NY 2013.
  16. Wang BR, Wang HC, Li LW, et al. Comparative efficacy of thienpydin, pyrantel pamoate, mebendazole and albendazole in treating ascariasis and enterobiasis. Chin Med J (Engl) 1987; 100:928.
  17. Horton J. Albendazole: a review of anthelmintic efficacy and safety in humans. Parasitology 2000; 121 Suppl:S113.
  18. St Georgiev V. Chemotherapy of enterobiasis (oxyuriasis). Expert Opin Pharmacother 2001; 2:267.
  19. Lormans JA, Wesel AJ, Vanparus OF. Mebendazole (R 17635) in enterobiasis. A clinical trial in mental retardates. Chemotherapy 1975; 21:255.
  20. Naquira C, Jimenez G, Guerra JG, et al. Ivermectin for human strongyloidiasis and other intestinal helminths. Am J Trop Med Hyg 1989; 40:304.
  21. Ottesen EA, Campbell WC. Ivermectin in human medicine. J Antimicrob Chemother 1994; 34:195.
  22. Heukelbach J, Wilcke T, Winter B, et al. Efficacy of ivermectin in a patient population concomitantly infected with intestinal helminths and ectoparasites. Arzneimittelforschung 2004; 54:416.
  23. Tietze PE, Jones JE. Parasites during pregnancy. Prim Care 1991; 18:75.
  24. Van Riper G. Pyrantel pamoate for pinworm infestation. Am Pharm 1993; NS33:43.
  25. Diav-Citrin O, Shechtman S, Arnon J, et al. Pregnancy outcome after gestational exposure to mebendazole: a prospective controlled cohort study. Am J Obstet Gynecol 2003; 188:282.
  26. Cooper E. Trichuriasis. In: Tropical Infectious Diseases: Principles, Pathogens and Practice, 3rd ed, Guerrant R, Walker DH, Weller PF (Eds), Saunders Elsevier, Philadelphia 2011. p.791.
  27. Bundy DA. Epidemiological aspects of Trichuris and trichuriasis in Caribbean communities. Trans R Soc Trop Med Hyg 1986; 80:706.
  28. Nokes C, Grantham-McGregor SM, Sawyer AW, et al. Moderate to heavy infections of Trichuris trichiura affect cognitive function in Jamaican school children. Parasitology 1992; 104 ( Pt 3):539.
  29. Forrester JE, Bailar JC 3rd, Esrey SA, et al. Randomised trial of albendazole and pyrantel in symptomless trichuriasis in children. Lancet 1998; 352:1103.
  30. Tarafder MR, Carabin H, Joseph L, et al. Estimating the sensitivity and specificity of Kato-Katz stool examination technique for detection of hookworms, Ascaris lumbricoides and Trichuris trichiura infections in humans in the absence of a 'gold standard'. Int J Parasitol 2010; 40:399.
  31. Knopp S, Speich B, Hattendorf J, et al. Diagnostic accuracy of Kato-Katz and FLOTAC for assessing anthelmintic drug efficacy. PLoS Negl Trop Dis 2011; 5:e1036.
  32. Rossignol JF, Maisonneuve H. Benzimidazoles in the treatment of trichuriasis: a review. Ann Trop Med Parasitol 1984; 78:135.
  33. Hall A, Nahar Q. Albendazole and infections with Ascaris lumbricoides and Trichuris trichiura in children in Bangladesh. Trans R Soc Trop Med Hyg 1994; 88:110.
  34. Speich B, Ame SM, Ali SM, et al. Oxantel pamoate-albendazole for Trichuris trichiura infection. N Engl J Med 2014; 370:610.
  35. Steinmann P, Utzinger J, Du ZW, et al. Efficacy of single-dose and triple-dose albendazole and mebendazole against soil-transmitted helminths and Taenia spp.: a randomized controlled trial. PLoS One 2011; 6:e25003.
  36. Sirivichayakul C, Pojjaroen-Anant C, Wisetsing P, et al. The effectiveness of 3, 5 or 7 days of albendazole for the treatment of Trichuris trichiura infection. Ann Trop Med Parasitol 2003; 97:847.
  37. Moser W, Ali SM, Ame SM, et al. Efficacy and safety of oxantel pamoate in school-aged children infected with Trichuris trichiura on Pemba Island, Tanzania: a parallel, randomised, controlled, dose-ranging study. Lancet Infect Dis 2016; 16:53.
  38. Speich B, Ali SM, Ame SM, et al. Efficacy and safety of albendazole plus ivermectin, albendazole plus mebendazole, albendazole plus oxantel pamoate, and mebendazole alone against Trichuris trichiura and concomitant soil-transmitted helminth infections: a four-arm, randomised controlled trial. Lancet Infect Dis 2015; 15:277.
  39. Marti H, Haji HJ, Savioli L, et al. A comparative trial of a single-dose ivermectin versus three days of albendazole for treatment of Strongyloides stercoralis and other soil-transmitted helminth infections in children. Am J Trop Med Hyg 1996; 55:477.
  40. Juan JO, Lopez Chegne N, Gargala G, Favennec L. Comparative clinical studies of nitazoxanide, albendazole and praziquantel in the treatment of ascariasis, trichuriasis and hymenolepiasis in children from Peru. Trans R Soc Trop Med Hyg 2002; 96:193.