Rodents are the primary definitive hosts, and grain beetles, fleas, or other insects feed on contaminated rodent droppings as intermediate. Hymenolepis nana infection is observed in households with poor hygiene and overcrowding, and can have a prevalence of 525% in children 54. It is small and measures up to 2540 mm in length by one mm in diameter. Hymenolepis nana, also known as dwarf tapeworm, is a cyclophyllidean tapeworm with embryonated eggs. Areas of endemicity up to 26% prevalence include asia, southern and eastern europe, central and south. The species name nana is derived from its small size which means dwarf of the adult worm. Hymenolepiasis is infestation by one of two species of tapeworm. Himenolepiasis parasitologia humana accessmedicina.
Malignant transformation of hymenolepis nana in a human host to the editor. Eggs hatch in the duodenum, releasing oncospheres, which penetrate the mucosa and come to lie in lymph channels of the villi. In 1906, stiles identified an identical parasite with a rodent host and named it hymenolepis fraterna. Dwarf tapeworm hymenolepis nana, also known as rodentolepis nana, vampirolepis nana, hymenolepis fraterna, and taenia nana is a cosmopolitan species though most common in temperate zones, and is one of the most common cestodes a type of intestinal worm or helminth infecting humans, especially children. What is hymenolepis nana infection the dwarf tapeworm or hymenolepis nana is found worldwide. Malignant transformation of hymenolepis nana in a human. Later, morphological characteristics were used for taxonomy identification and h. It is often referred to as the dwarf tapeworm due to its small size, 24 cm long and only 1 mm wide 1 fig. Laboratory diagnostic of hymenolepis nana dwarf tapeworm.
The worms mature into a life form referred to as a cysticercoid in the insect. Human infection is usually asymptomatic, it but can cause mild gastrointestinal symptoms. Nov 22, 2015 hymenolepiasis is the term when a human is infected with either h. As mentioned above, hymenolepis nana does not require an intermediate host to complete its life cycle. Drugs used to treat dwarf tapeworm infection hymenolepis nana the following list of medications are in some way related to, or used in the treatment of this. Malignant transformation of hymenolepis nana in a human host. It is interesting to note that the cysticercoid larval stage can develop in these hosts when this happens. Hymenolepis nana hymenolepis diminuta valeria chinchilla. Hymenolepis nana dwarf tapeworm infection infectious. Hymenolepis nana definition of hymenolepis nana by medical. Hymenolepiasis is an infection caused by hymenolepis nana h. Its larvae migrate only within the gut wall, and its life span is relatively short 4 to 6 wk. Transactions of the royal society of tropical medicine and hygiene 101.
The adult worm resides in the ileal portion of the small intestine. Hymenolepis diminuta, also known as rat tapeworm, is a species of hymenolepis tapeworm that causes hymenolepiasis. Hymenolepis nana has been called the dwarf tapeworm and has a worldwide distribution. Prevalence of giardia intestinalis and hymenolepis nana in afghan refugee population of mianwali district, pakistan. Differential diagnosis and molecular characterization of. The aim of this study was to determine the prevalence in a health area of southern spain. It has a cosmopolitan distribution and is thought to be the most common tapeworm throughout the world. Review of dwarf tapeworm hymenolepis nana presentations to northern territory nt government healthcare facilities over 12 years. Eggs of hymenolepis nana are immediately infective when passed with the stool and cannot survive more than 10 days in the external environment. On the inner membrane are two poles, from which 4 to 8 polar filaments spread out between the two membranes. Humans and other animals become infected when they intentionally or.
Hymenolepis nana is the most common tapeworm in humans. It is possible for the worms entire life cycle to be completed in the bowel, so infection can. Humans, rodents most common tapeworm of humans in the world 1% rate of infection in the southern u. Hymenolepiasis is prevalent throughout the world with human infections with h. Larval and adult beetles but optional larval stage, cysticercoid, can develop.
It is the smallest and only cestode that parasites the human without any intermediate host. For precise diagnosis of the species, molecular techniques such as pcr and rflp of the nuclear ribosomal internal transcribed spacer 2 rdnaits2 gene marker were carried out. Development hymenolepis nana life cycle infection is acquired most commonly from eggs in the feces of another infected individual, which are transferred in food, by contamination. Hymenolepis nana is an intestinal cestode causing tapeworm infection in humans with a worldwide distribution. See more ideas about medical laboratory, microbiology and medical laboratory science. She remained well in spite of treatment, even though. It is the only cestode that does not require an intermediate host to develop into its infective stage. However, this parasite may be present in a number of other animal transport hosts, such as fleas, beetles, rats and house mice. Praziquantel, adults and children, 25mgkg in a singledose therapy alternatives. Hymenolepiasis is the most common intestinal tapeworm infection of humans caused by worm of family cestoda, genus hymenolepis and species nana. Hymenolepis nana, the dwarf tapeworm, is the smallest tapeworm to infect humans. E ggs of the tapeworm hymenolepis nana are infective when passed with the stool, but cannot survive more than about 10 days outside the body when eggs are ingested by an arthropod intermediate host a variety of fleas and beetles can serve as intermediate hosts, they develop into cysticercoids, which can infect humans or rodents upon ingestion and develop into adults in the small intestine. If larvabearing eggs enter the human gastrointestinal tract, the oncospheres are released into the duodenum and attatch to the villi, where each develops into a cysticercoid. Apr 20, 2015 hymenolepiasis is the most common intestinal tapeworm infection of humans caused by worm of family cestoda, genus hymenolepis and species nana.
Hymenolepis nana pathogen intestinal cestode organism. Hymenolepis nana, the dwarf tapeworm, is the smallest tapeworm found in the intestines of broad range of dogs, rats and humans. Larval and adult beetles but optional larval stage, cysticercoid, can develop in d. Creepy dreadful wonderful parasites blog case of the week 539 accessed 18 april 2019. Here, we present a case of a renal transplant recipient who presented with abdominal pain and developed diarrhea. Hymenolepis diminuta infection infectious diseases msd. Diplacanthus manus, hymenolepis nana, hymenolepis murina. Radiographic and pathological features of malignant hymenolepis nana anteroposterior and axial ct scans in panels a and b, respectively, show the. Biologia simplificada com emerson inacio 6,583 views. Hymenolepis nana has a worldwide distribution with estimates of 5075 million carriers. Clinicopathological studies on spontaneous hymenolepis. This infection does not require an intermediate host and infection can occur directly from one infected person to another by fecaloral transmission. Infection is most common in children, in persons living in institutional settings, and in people who live in areas where sanitation and personal hygiene is inadequate. Transmission of hymenolepiasis stanford university.
Given the widespread distribution and medical implication of members of the genus hymenolepis, specific identification of the aetiological agent becomes imperative. In the southeastern usa, as many as 1% of young schoolchildren. Hymenolepis nana introduction hymenolepis nana, the dwarf tapeworm, is the smallest tapeworm to infect humans. Hymenolepis rodentolepis nana is the most common cestode of humans, particularly in young children. Hymenolepis nana is one of the most common tapeworms a helminth with a flat, ribbonlike, segmented body. The adult structure is 20 to 60 cm long and the mature proglottid is similar to that of h. Hymenolepis nana is the smallest of all tapeworms found in humans and is appropriately described as the dwarf tapeworm. Hymenolepiasis is more frequent among children, and most human infections remain asymptomatic and selflimited. In this video we can see the movement of an adult of hymenolepis nana, observation under a microscope with the objective of 4x magnifying glass. It requires only one host but can also cycle through two. It has slightly bigger eggs and proglottids than h.
The fact that an intermediate host is not required in the life cycle was determined in the late 1800s. Alternative names are dwarf tapeworm infection and rat tapeworm infection. Hymenolepis nana, a tiny intestinal tapeworm, is the most common human cestode. Humans and other animals become infected when they intentionally or unintentionally eat material contaminated by insects. Hymenolepis nana, a tiny intestinal tapeworm, is one of the most common human cestodes.
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 hostsbeetles. Cacing ini tidak memiliki hospes intermedier sehingga disebut dengan non obligatory intermedier, sedangkan hospes definitifnya adalah manusia. This cestode belongs to a large family known as hymenolepididae. He recovered a countless number of them at a postmortem on a boy who had died of meningitis. When eggs are ingested by an arthropod intermediate host various species of beetles and fleas may serve as intermediate hosts, they develop into cysticercoids, which can infect humans or rodents upon.
Hymenolepis diminuta is a tapeworm that can cause intestinal infection in humans. Only the murine rat tapeworm, hymenolepis diminuta, is used in helminthic therapy and this generally does not reach adulthood in humans so requires regular dosing of hdc. Cdc hymenolepis resources for health professionals. Hymenolepiasis is the term when a human is infected with either h. Hymenolepis nana dwarf tapeworm parasites in humans. Himenolepiasis parasitologia medica, 4e accessmedicina.
For precise diagnosis of the species, molecular techniques such as pcr and rflp of. It is also known as the dwarf tapeworm due to its particularly small size adults are only 1540 mm long. Hymenolepis nana is also known as the dwarf tapeworm. The authors cite some ear lier cases as examples of proliferating. The disease is a type of helminthiasis which is classified as a neglected tropical disease. Hymenolepis nana, the dwarf or dwarf mouse tapeworm, is a small tapeworm in humans, sometimes found in great numbers in the intestine. Hymenolepis nana life cycle online biology dictionary. The dwarf tapeworm was found in man for the first time by bilharz, in cairo, egypt, in 1851.
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