Hymenolepiasis

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This article is about the infection. For the organism, see Hymenolepis nana.
Hymenolepiasis
Other names: Hymenolepis infectious disease[1]
Lifecycle of H. nana
SpecialtyInfectious disease
SymptomsAbdominal pain, diarrhea, and vomiting[2]
ComplicationsDehydration[3]
CausesHymenolepis nana or Hymenolepis diminuta[2]
Diagnostic methodStool exam[2]
Differential diagnosisAmebiasis,Cystoisosporiasis,Cryptosporidiosis[4]
PreventionGood hygiene[2]
TreatmentPraziquantel or niclosamide or nitazoxanide [2]

Hymenolepiasis is infestation by one of two species of tapeworm: Hymenolepis nana or H. diminuta. Alternative names are dwarf tapeworm infection and rat tapeworm infection. The disease is a type of helminthiasis which is classified as a neglected tropical disease.[5][6][7]

The treatment of hymenolepiasis, entails you take praziquantel, niclosamide , or nitazoxanide.[8]

Symptoms and signs

Hymenolepiasis does not always have symptoms, but they usually are described as abdominal pain, loss of appetite, itching around the anus, irritability, and diarrhea.[9] Some authorities report that heavily infected cases are more likely to be symptomatic.[10][11]Symptoms in humans are due to allergic responses or systematic toxaemia caused by waste products of the tapeworm. Light infections are usually symptomless, whereas infection with several thousand worms can cause enteritis, abdominal pain, diarrhea, loss of appetite, restlessness, irritability, restless sleep, and anal and nasal pruritus. [3][2][7]

Complications

Abdominal discomfort and, in case of prolonged diarrhea, dehydration are possible complications.[3]In 2015 an unusual complication was noted in a man whose immune system had been compromised by HIV. He developed multiple tumors of malignant cell nests within his body that had originated from a tapeworm in his intestines.[12]

Causes

Hymenolepis worms live in the intestines of rats and are common in warm climates, and are generally found in the feces of rats, which are consumed by their secondary hosts—beetles. The worms mature into a life form referred to as a "cysticercoid" in the insect; in H. nana, the insect is always a beetle. Humans and other animals become infected when they intentionally or unintentionally eat material contaminated by insects. In an infected person, it is possible for the worm's entire lifecycle to be completed in the bowel, so infection can persist for years if left untreated. H. nana infections are much more common than H. diminuta infections in humans because, in addition to being spread by insects, the disease can be spread directly from person to person by eggs in feces. When this happens, H. nana oncosphere larvae encyst in the intestinal wall and develop into cysticercoids and then adults. These infections were previously common in the southeastern U.S., and have been described in crowded environments and individuals confined to institutions. However, the disease occurs throughout the world. [2][7][13]

H. diminuta

Hymenolepis diminuta

The risk of human infection from H. diminuta is very low, since its main host is the rat. Also known as the rat tapeworm, H. diminuta adults live and mate in the bowels of rats. Eggs of H. diminuta are excreted by the rats in droppings, which are frequently consumed by beetles. Once inside the beetle, the eggs mature into a cysticercoid. [14]

The juvenile tapeworms claw their way out of the beetle gut into the circulatory system by means of their three pairs of hooks. There, they wait for a rat to ingest the host beetle, where they mature to adult form, lay eggs, and restart the entire cycle.[14]

H. diminuta has an effective mechanism for interspecies transfection. Beetles prefer to ingest rat droppings infected with tapeworm eggs, because of their odor. It is not known if the odor is produced specifically by the eggs or the droppings. H. diminuta also sterilizes its beetle host, if female. This is so the beetle does not waste energy in its reproductive system, allowing H. diminuta to further exploit the beetle's metabolic resources.[14]

H. nana

Ultrastructural details exhibited by single Hymenolepis nana tapeworm ovum

H. nana is a tapeworm, belonging to the class Cestoidea, phylum Platyhelminthes. It consists of a linear series of sets of reproductive organs of both sexes; each set is referred to as a genitaluim and the area around it is a proglottid. New proglottids are continuously differentiated near the anterior end in a process called strobilation. Each segment moves toward the posterior end as a new one takes its place and, during the process, becomes sexually mature. The proglottid can copulate with itself, with others in the strobilla, or with those in other worms. When the segment reaches the end of its strobila, it disintegrates en route, releasing eggs in a process called apolysis.H. nana is the only cestode capable of completing its lifecycle without an intermediate host.It can, however, pass through an intermediate host, as well. The most common intermediate hosts for H. nana are arthropods. When an egg is ingested by the definitive host, it hatches and releases a six-hook larva called the oncosphere which penetrates the villi of the small intestine and develops into a cysticercoid.[10][15] [16]

Mechanism

H. nana lodges itself in the intestines and absorbs nutrients from the intestinal lumen. In human adults, the tapeworm is more of a nuisance than a health problem, but in small children, many H. nana worms can be dangerous. Usually, the larvae of this tapeworm cause the most problem in children; they burrow into the walls of the intestine, and if enough tapeworms are present in the child, severe damage can be inflicted. This is done by absorbing all the nutrients from the food the child eats. Usually, a single tapeworm will not cause health issues. H. nana usually will not cause deaths unless in extreme circumstances and usually in young children or in people who have weakened immune systems. In some parts of the world, individuals who are heavily infected are a result of internal autoinfection.[17][7][13]

Diagnosis

The diagnosis of Hymenolepiasis can be done via demonstration of eggs in stool specimens. The eggs and proglottids of H. nana are smaller than H. diminuta. Proglottids of both are relatively wide and have three testes. Identifying the parasites to the species level is often unnecessary from a medical perspective, as the treatment is the same for both.[17][7][18]

  • Egg of H. diminuta in a wet mount(stained with iodine)[17]

    Egg of H. diminuta in a wet mount(stained with iodine)[17]

  • a-d)Via a colonoscopy numerous amount of Hymenolepis nana adult worms were found scattered throughout a colon

    a-d)Via a colonoscopy numerous amount of Hymenolepis nana adult worms were found scattered throughout a colon

Differential diagnosis

Irritable bowel syndrome

In so far as the DDx we find the following:[4]

Prevention

Good hygiene, public health and sanitation programs, and elimination of infected rats help to prevent the spread of hymenolepiasis. Preventing fecal contamination of food and water in institutions and crowded areas is of primary importance. General sanitation and rodent and insect control are also essential for prevention of H. nana infection.[3][7]

Treatment

Praziquantel

The two drugs that have been well-described for the treatment of hymenolepiasis are praziquantel and niclosamide. Praziquantel, which is parasiticidal in a single dose for all the stages of the parasite, is the drug of choice because it acts very rapidly against H. nana. Although structurally unrelated to other anthelminthics, it kills both adult worms and larvae. In vitro, the drug produces vacuolization and disruption of the tegument in the neck of the worms, but not in more posterior portions of the strobila. Praziquantel is well absorbed when taken orally, and it undergoes first-pass metabolism and a high percentage of the dose is excreted as metabolites in urine within 24 hours. Repeated treatment is required for H. nana at an interval of 7–10 days.[3][2][7]

Praziquantel as a single dose (25 mg/kg) is the current treatment of choice for hymenolepiasis and has high efficacy[19]

A three-day course of nitazoxanide is 75–93% efficacious. The dose is 1 g daily for adults and children over 12; 400 mg daily for children aged 4 to 11 years; and 200 mg daily for children aged 3 years or younger.[9][20][21]

Prognosis

Cure rates are extremely good with modern treatments, but successful cure results may be of no symptomatic benefit to patients.[9]

Epidemiology

In terms of the epidemiology we find that H. nana infection is prevalent in countries of the Mediterranean, Indian subcontinent, South America and other parts of the world. In children in these countries prevalence can reach 20 percent. [22]

  • Prevalence of Hymenolepis nana in Burkina Faso[23]

    Prevalence of Hymenolepis nana in Burkina Faso[23]

  • Observed and predicted prevalence of Hymenolepis nana infection(Angola)[24]

    Observed and predicted prevalence of Hymenolepis nana infection(Angola)[24]

History

Hymenolepiasis was first discovered by Theodor Bilharz in 1851, he identified the dwarf tapeworm, Hymenolepis nana, in the small intestine.[25]

See also

References

  1. ↑ "Hymenolepiasis | Genetic and Rare Diseases Information Center (GARD) – an NCATS Program". rarediseases.info.nih.gov. Archived from the original on 26 June 2021. Retrieved 17 December 2024.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 "About Hymenolepiasis (Dwarf Tapeworm)". Hymenolepiasis. 11 July 2024. Retrieved 19 December 2024.
  3. ↑ 3.0 3.1 3.2 3.3 3.4 "Tapeworm infection - hymenolepis: MedlinePlus Medical Encyclopedia". medlineplus.gov.
  4. ↑ 4.0 4.1 "Tapeworm Infestation Differential Diagnoses". emedicine.medscape.com. Archived from the original on 24 November 2024. Retrieved 20 December 2024.
  5. ↑ "Orphanet: Hymenolepiasis". www.orpha.net. Retrieved 18 December 2024.
  6. ↑ "hymenolepiasis - National Organization for Rare Disorders". rarediseases.org. Archived from the original on 1 December 2024. Retrieved 18 December 2024.
  7. ↑ 7.0 7.1 7.2 7.3 7.4 7.5 7.6 Bhosale, Namrata K. (2022). "Hymenolepiasis". Textbook of Parasitic Zoonoses. Springer Nature. pp. 385–392. ISBN 978-981-16-7204-0. Retrieved 26 December 2024.
  8. ↑ "Clinical Care of Hymenolepiasis (Dwarf Tapeworm)". Hymenolepiasis. 8 November 2024. Archived from the original on 5 October 2024. Retrieved 23 December 2024.
  9. ↑ 9.0 9.1 9.2 Chero JC, Saito M, Bustos JA, et al. (2007). "Hymenolepis nana infection: symptoms and response to nitazoxanide in field conditions". Trans R Soc Trop Med Hyg. 101 (2): 203–5. doi:10.1016/j.trstmh.2006.04.004. PMID 16814334.
  10. ↑ 10.0 10.1 Schantz PM (September 1996). "Tapeworms (cestodiasis)". Gastroenterol. Clin. North Am. 25 (3): 637–53. doi:10.1016/S0889-8553(05)70267-3. PMID 8863044. Archived from the original on 2022-01-11. Retrieved 2021-05-24.
  11. ↑ Chitchang S, Plamjinda T, Yodmani B, Radomyos P (1985). "Relationship between severity of the symptom and the number of Hymenolepis nana after treatment". J Med Assoc Thai. 68 (8): 423–26. PMID 4067462.
  12. ↑ Muehlenbachs, A; et al. (2015). "Malignant Transformation of Hymenolepis nana in a Human Host". New England Journal of Medicine. 373 (19): 1845–1852. doi:10.1056/NEJMoa1505892. PMID 26535513. S2CID 2806255. Archived from the original on 2022-01-11. Retrieved 2021-05-24.
  13. ↑ 13.0 13.1 Mathison, Blaine A.; Pritt, Bobbi S. (1 January 2022). "Parasites of the Gastrointestinal Tract". Encyclopedia of Infection and Immunity. Elsevier. pp. 136–203. ISBN 978-0-323-90303-5.
  14. ↑ 14.0 14.1 14.2 Zimmer, Carl (2001). Parasite rex: inside the bizarre world of nature's most dangerous creatures. New York: Simon & Schuster. ISBN 0-7432-0011-X.
  15. ↑ Smyth, J.D.; McManus, D.P. (2007). The Physiology and Biochemistry of Cestodes. Cambridge University Press. ISBN 978-0-521-03895-9. Archived from the original on 2013-06-06. Retrieved 2021-05-24.
  16. ↑ Bogitsh, Burton J.; Carter, Clint E.; Oeltmann, Thomas N. (1 January 2013). "Chapter 13 - Intestinal Tapeworms". Human Parasitology (Fourth Edition). Academic Press. pp. 237–249. ISBN 978-0-12-415915-0. Archived from the original on 11 March 2024. Retrieved 30 December 2024.
  17. ↑ 17.0 17.1 17.2 "CDC - DPDx - Hymenolepiasis". www.cdc.gov. 18 January 2019. Archived from the original on 16 December 2021. Retrieved 16 December 2021.
  18. ↑ Panti-May, Jesús Alonso; Rodríguez-Vivas, Roger Iván; García-Prieto, Luis; Servián, Andrea; Costa, Federico (July 2020). "Worldwide overview of human infections with Hymenolepis diminuta". Parasitology Research. 119 (7): 1997–2004. doi:10.1007/s00436-020-06663-x. ISSN 1432-1955.
  19. ↑ Chai, Jong-Yil (2013). "Praziquantel Treatment in Trematode and Cestode Infections: An Update". Infection & Chemotherapy. 45 (1): 32. Retrieved 24 December 2024.
  20. ↑ Ortiz JJ, Favennec L, Chegne NL, Gargala G (2002). "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. 96 (2): 193–96. doi:10.1016/S0035-9203(02)90301-9. PMID 12055813.
  21. ↑ Romero Cabello R, Guerrero LR, Muñóz García MR, Geyne Cruz A (1997). "Nitazoxanide for the treatment of intestinal protozoan and helminthic infections in Mexico". Trans. R. Soc. Trop. Med. Hyg. 91 (6): 701–3. doi:10.1016/S0035-9203(97)90531-9. PMID 9580117.
  22. ↑ "Tapeworm Infestation: Background, Pathophysiology, Epidemiology". eMedicine. 2 August 2024. Archived from the original on 23 December 2024. Retrieved 27 December 2024.
  23. ↑ Bagayan*, Mohamed; Zongo, Dramane; Ouéda, Adama; Savadogo, Boubacar; Sorgho, Hermann; Drabo, François; Ouédraogo, Amado; Bamba, Issouf; Zhang, Yaobi; Kabré, Gustave Boureima; Poda, Jean Noël (31 December 2015). "Prevalence of Hymenolepis nana among primary school children in Burkina Faso". International Journal of Medicine and Medical Sciences. 7 (10): 148–153. doi:10.5897/IJMMS2015.1179. ISSN 2006-9723. Archived from the original on 17 June 2022. Retrieved 4 January 2025.
  24. ↑ Soares Magalhães, Ricardo J.; Fançony, Cláudia; Gamboa, Dina; Langa, António J.; Sousa-Figueiredo, José Carlos; Clements, Archie C. A.; Vaz Nery, Susana (24 October 2013). "Extending Helminth Control beyond STH and Schistosomiasis: The Case of Human Hymenolepiasis". PLoS Neglected Tropical Diseases. 7 (10): e2321. doi:10.1371/journal.pntd.0002321.
  25. ↑ Goudarzi, Fatemeh; Mohtasebi, Sina; Teimouri, Aref; Yimam, Yonas; Heydarian, Peyman; Salehi Sangani, Ghodratollah; Abbaszadeh Afshar, Mohammad Javad (1 February 2021). "A systematic review and meta-analysis of Hymenolepis nana in human and rodent hosts in Iran: A remaining public health concern". Comparative Immunology, Microbiology and Infectious Diseases. 74: 101580. doi:10.1016/j.cimid.2020.101580. ISSN 0147-9571. Archived from the original on 15 April 2024. Retrieved 23 December 2024.

External links

Classification
External resources
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