関: Trichina、Trichinella

WordNet

form a spiral; "The path spirals up the mountain"
a continuously accelerating change in the economy
a plane curve traced by a point circling about the center but at increasing distances from the center
ornament consisting of a curve on a plane that winds around a center with an increasing distance from the center (同)volute
flying downward in a helical path with a large radius

PrepTutorEJDIC

らせん(helix) / らせん状のもの;らせんばね;巻き貝 / (物価・賃金などの)らせん状上昇(下降) / らせん状の /… ‘を'らせん形にする / らせん形になる;らせん状に動く

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/03/28 20:34:36」(JST)

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Trichinella spiralis is a nematode parasite, occurring in rats, pigs, bears and humans, and is responsible for the disease trichinosis. It is sometimes referred to as the "pork worm" due to it being found commonly in undercooked pork products.

Description

Trichinella species are the smallest nematode parasite of humans, have an unusual life cycle and are one of the most widespread and clinically important parasites in the world.^[1] The small adult worms mature in the intestines of an intermediate host such as a pig. Each adult female produces batches of live larvae, which bore through the intestinal wall, enter the blood (to feed on it) and lymphatic system, and are carried to striated muscle. Once in the muscle, they encyst, or become enclosed in a capsule. Humans can be infected by eating infected pork or horse or wild carnivores such as fox, cat or bear.^[1]

Morphology

Males of T. spiralis measure between 1.4 mm and 1.6 mm long and are more flat anteriorly than posteriorly. The anus can be found in the terminal (side) and they have a large copulatory pseudobursa on each side.^[1] The females of T. spiralis are about twice the size of the males and have an anus found terminally. The vulva is located near the esophagus. The single uterus of the female is filled with developing eggs in the posterior portion, while the anterior portion contained the fully developed juveniles.^[1]

Life cycle

Trichinella spiralis is a parasitic nematode that has a direct life cycle, meaning it completes all stages of development in one host. The larval forms are encapsulated as a small cystic structure within the infected host. Humans typically become infected when they eat improperly cooked pork or Trichinella infected meat. When a human eats the infected meat, the larvae are released from the nurse cell (due to stomach pH) and migrate to the intestine, where they burrow into the intestinal mucosa, mature, and reproduce.^[2] Juveniles within nurse cells have an anaerobic or facultative anaerobic metabolism, but when they become activated, they adopt an aerobic metabolism characteristics of the adult.^[1] Female Trichinella worms live for about six weeks, and in that time can produce up to 1,500 larvae; when a spent female dies, she passes out of the host. The larvae can then gain access to the circulation and migrate around the body of the host.^[2] The migration and encystment of larvae can cause fever and pain brought upon by the host inflammatory response. In some cases, migration to specific organ tissues can cause myocarditis and encephalitis that can result in death.

Nurse cell formation

This nematode is a multi-celular parasite that lives within a single muscle cell, which it modifies according to its own requirements.^[3]

Trichinella spiralis larvae within the diaphragm muscle of a pig

Nurse cell formation in skeletal muscle tissue is mediated by the hypoxic environment surrounding the new vessel formation.^[4] The hypoxic environment stimulates cells in the surrounding tissue to regulate up and secrete angiogenic cytokines, such as VEGF. This allows for the newborn T. spinalis larvae to enter and form the nurse cells. VEGF expression is detected surrounding the nurse cell right after nurse cell formation, and the continued secretion of VEGF can maintain the constant state of hypoxia.^[5] Previous studies have shown VEGF can stimulate proliferation of synthesis of collagen type 1 in activated myofibroblast-like cells.^[6]

Symptoms

The first symptoms may appear between 12 hours and two days after ingestion of infected meat. The migration of worms in the intestinal epithelium can cause traumatic damage to the host tissue, and the waste products they excrete can provoke an immunological reaction.^[1] The resulting inflammation can cause symptoms such as nausea, vomiting, sweating and diarrhea. Five to seven days after the appearance of symptoms, facial edema and fever may occur. After 10 days, intense muscular pain, difficulty breathing, weakening of pulse and blood pressure, heart damage and various nervous disorders may occur, eventually leading to death due to heart failure, respiratory complications or kidney malfunction.^[1]

In pigs, infection is usually subclinical but large numbers of worms can be fatal in some cases.^[7]

Diagnosis and treatment

Muscle biopsy is used for trichinosis detection. Several immunodiagnostic tests are also available. Typically, patients are treated with either mebendazole or albendazole, but efficacy of such products are uncertain. Symptoms can be relieved by use of analgesics and corticosteroids.^[1]

In pigs, ELISA testing is possible as a method of diagnosis. Anthelmintics can treat and prevent Trichinella infections.^[7]

Prevention and control

Trichinosis (also trichinellosis) is a disease caused by tissue-dwelling roundworms of the species Trichinella spiralis. In the United States, the national trichinellosis surveillance system has documented a steady decline in the reported incidence of this disease. During 1947 to 1951, a median of 393 cases was reported annually, including 57 trichinellosis-related deaths. During 1997-2001, the incidence decreased to a median of 12 cases annually, with no reported deaths. The decline of infection was largely associated with changes implemented by the U.S. pork industry that have resulted in reduced prevalence of Trichinella among domestic swine.^[8] In the United States, Congress passed the Federal Swine Health Protection Act restricting the use of uncooked garbage as feed stock for pigs and creating a voluntary Trichinae Herd Certification Program.^[8] The Trichinae Herd Certification Program is a voluntary preharvest pork safety program that provides documentation of swine management practices to minimize Trichinella exposure. The goal of the program is to establish a system under which pork production facilities that follow good production practices might be certified as Trichinella-safe.^[9] In addition to the reduction in Trichinella prevalence in commercial pork, processing methods also have contributed to the dramatic decline in human trichinellosis associated with pork products. Through the U.S. Code of Federal Regulations, USDA has created guidelines for specific cooking temperatures and times, freezing temperatures and times, and curing methods for processed pork products to control postharvest human exposure to Trichinella.^[8] Pork products meeting these guidelines are designated certified pork.

In most abattoirs, the diaphragm of pigs is routinely sampled to detect Trichinella infection.^[7]

Genome

The Trichinella spiralis draft genome became available in March 2011.^[10] The genome size was 58.55 Mbp with an estimated 16,549 genes.^[11] It was subsequently shown that the Trichinella spiralis genome is the only known nematode genome to be subject to DNA methylation,^[12] an epigenetic mechanism that was not previously thought to exist in nematodes.

Notes

^ ^a ^b ^c ^d ^e ^f ^g ^h Roberts, Larry S., John Janovay (2005). Foundations of Parasitology (7th ed.). New York: McGraw-Hill. pp. 405–407.
^ ^a ^b Crowley, Leonard (2009). An Introduction to Human Disease: Pathology and Pathophysiology Correlations (8th ed.). Jones and Bartlett.
^ Combes, Claude (2005). The art of Being a Parasite (English translation ed.). The University of Chicago Press.
^ Fong GH (2008). "Mechanism of adaptative angiogenesis to tissue hypoxia". Angiogenesis 11: 121–140.
^ Capo VA, Despommier DD, Polvere RI (1998). "Trichinella spiralis: vascular endothelial growth factor is up-regulated within the nurse cell during the early phase of its formation". J. Parasitol. 84: 209–214.
^ Novo E, Cannito S, Zamara E, Valfre di Bonzo L, Caligiuri A, Cravanzola C, et al. (2007). "Proangiogenic cytokines as hypoxia-dependent factors stimulating migration of human hepatic stellate cells". Am. J. Pathol. 170: 1942–1953.
^ ^a ^b ^c "Trichinella". WikiVet. http://en.wikivet.net/Trichinella. Retrieved 12 October 2011.
^ ^a ^b ^c Roy, Sharon L., Adriana S. Lopez, and Peter M. Schantz. "Trichinellosis Surveillance --- United States, 1997--2001." Center for Disease Control
^ National Pork Board. Trichinae Herd Certification. Des Moines, Iowa: National Pork Producers Council, 2000. Available at http://www.aphis.usda.gov/vs/trichinella/.
^ "Trichinella spiralis". Genome. NCBI. http://www.ncbi.nlm.nih.gov/genome?term=Trichinella%20spiralis. Retrieved 2012-04-19.
^ Mitreva M, Jasmer DP, Zarlenga DS, Wang Z, Abubucker S, Martin J, Taylor CM, Yin Y, Fulton L, Minx P, Yang SP, Warren WC, Fulton RS, Bhonagiri V, Zhang X, Hallsworth-Pepin K, Clifton SW, McCarter JP, Appleton J, Mardis ER, Wilson RK (March 2011). "The draft genome of the parasitic nematode Trichinella spiralis". Nat. Genet. 43 (3): 228–235. doi:10.1038/ng.769. PMC 3057868. PMID 21336279.
^ Gao F, Liu X, Wu XP, Wang XL, Gong D, Lu H, Xia Y, Song Y, Wang J, Du J, Liu S, Han X, Tang Y, Yang H, Jin Q, Zhang X, Liu M (October 2012). "Differential DNA methylation in discrete developmental stages of the parasitic nematode Trichinella spiralis". Genome Biol. 13 (10): R100. doi:10.1186/gb-2012-13-10-r100. PMID 23075480.

References

Despommier DD, Gwadz RG, Hotez P, Knirsch C (2002). Parasitic Diseases (5th ed.). New York: Apple Trees Pub.

External links

Wikimedia Commons has media related to: Trichinella spiralis

"The Trichinella Page". Trichinella.org. Columbia University. http://www.trichinella.org.
"Trichina life cycle". Centers for Disease Control and Prevention. http://www.dpd.cdc.gov/dpdx/html/Trichinellosis.htm.
"Trichina agent". Washington University. http://www.neuro.wustl.edu/neuromuscular/antibody/infmyop.htm#trichinosis.
Fluorescence image of Trichina

UpToDate Contents

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1. 旋毛虫症 trichinellosis
2. 遺伝性血管浮腫：病因および診断 hereditary angioedema pathogenesis and diagnosis
3. 肥満細胞：増殖・分化、識別、および生理学的役割 mast cells development identification and physiologic roles
4. 原因不明の好酸球増加症患者に対するアプローチ approach to the patient with unexplained eosinophilia
5. 駆虫薬療法 anthelminthic therapies

English Journal

Anti-Trichinella IgG in ethnic minorities living in Trichinella-endemic areas in northwest Vietnam: study of the predictive value of selected clinical signs and symptoms for the diagnosis of trichinellosis.

Vu Thi N1, Pozio E2, Van De N3, Praet N4, Pezzotti P2, Gabriël S4, Claes M4, Thuy NT5, Dorny P6.
Acta tropica.Acta Trop.2014 Nov;139:93-8. doi: 10.1016/j.actatropica.2014.07.012. Epub 2014 Jul 27.
The objective of this study was to assess the presence of anti-Trichinella IgG in the serum of persons from ethnic minorities from northwest Vietnam with clinical signs and symptoms that are compatible with trichinellosis. A total of 645 persons were enrolled, of which 200 people lived in two villag
PMID 25076109

The immature stages of Dermestes maculatus, Sarcophaga sp. and Phaenicia sericata as potential paratenic hosts for Trichinella spiralis in nature.

Riva E1, Fiel C, Steffan P.
Parasitology research.Parasitol Res.2014 Oct 28. [Epub ahead of print]
The role of some insect populations in the transmission of Trichinella sp. has been demonstrated. However, most of the studies have been conducted under controlled conditions which may influence the real role that they could play as a paratenic host in nature. To enlight this issue, a series of stud
PMID 25346194

Eosinophil-derived IL-10 supports chronic nematode infection.

Huang L1, Gebreselassie NG1, Gagliardo LF1, Ruyechan MC1, Lee NA2, Lee JJ3, Appleton JA4.
Journal of immunology (Baltimore, Md. : 1950).J Immunol.2014 Oct 15;193(8):4178-87. doi: 10.4049/jimmunol.1400852. Epub 2014 Sep 10.
Eosinophilia is a feature of the host immune response that distinguishes parasitic worms from other pathogens, yet a discrete function for eosinophils in worm infection has been elusive. The aim of this study was to clarify the mechanism(s) underlying the striking and unexpected observation that eos
PMID 25210122

Japanese Journal

寄生虫感染により誘導された非特異的IgEによるI型アレルギー反応の抑制

松岡裕之,大原一倫,田辺正樹
自治医科大学紀要 31, 1-8, 2008-12-01
… つぎにマウスを2群に分け,1群には旋毛虫Trichinella spiralis Polish strain (Tsp)を感染させ,残りの1群には感染させなかった。 …
NAID 110007020089

Candidate genes responsible for common and different pathology of infected muscle tissues between Trichinella spiralis and T. pseudospiralis infection

WU Zhiliang,NAGANO Isao,TAKAHASHI Yuzo
Parasitology international : official journal of the Japanese Society of Parasitology 57(3), 368-378, 2008-09-01
NAID 10025328883

Related Pictures

★リンクテーブル★

リンク元	「蠕虫」「旋毛虫」「Trichina」「トリキナ」
関連記事	「Trichinella」「spiral」

「蠕虫」

Trichinella spiralis
Scientific classification
Kingdom:	Animalia
Phylum:	Nemathelminthes
Class:	Nematoda
Order:	Enoplida
Superfamily:	Trichinelloidea
Genus:	Trichinella
Species:	T. spiralis
Binomial name
	Trichinella spiralis; (Owen, 1835)

　　[★]

英: helminth, worms
ラ: helminthen
関: 微生物学、蠕虫症、家畜伝染病予防法

蠕虫類

吸虫類 trematoda
条虫類 cestoda
線虫類 nematoda
鉤頭虫類 acanthocephala

蠕虫類と感染症

蠕虫類	病原体名		病名	感染経路	寄生部位	症状	診断	治療
線虫類	Ancylostoma duodenale	ズビニ鉤虫	鈎虫症/十二指腸虫症	F型幼虫経口感染、経皮	空腸上部	皮膚炎、若菜病、貧血	飽和食塩水浮遊法、遠心沈降法	pyrantel pamoate、鉄剤
	Necator americanus	アメリカ鉤虫	鈎虫症/十二指腸虫症	F型幼虫経口感染、経皮	空腸上部	皮膚炎、若菜病、貧血	飽和食塩水浮遊法、遠心沈降法	pyrantel pamoate、鉄剤
	Strongyloides stercoralis	糞線虫	糞線虫症	F型幼虫経皮感染	小腸上部	Loffler症候群	糞便塗沫、普通寒天平板培養による R型、F型幼虫の検出	thiabendazole, ivermectin
	Enterobius vermicularis	蟯虫	蟯虫症	虫卵経口感染	盲腸～大腸	夜間の掻痒、不眠、情緒不安定	肛囲検査法「柿の種」	pyrantel pamoate
	Ascaris lumbricoides	回虫	回虫症	虫卵経口感染	小腸孵化→門脈→ 肺発育→食道嚥下→小腸	Loffler症候群。急性腹痛	糞便虫の虫卵の証明	pyrantel pamoate
	Toxocara canis	イヌ回虫	幼虫移行症	生後1-2ヶ月の感染犬の糞から経口感染	なし	幼虫移行症→失明	免疫診断	治療法無し？
	Wuchereria bancrofti	バンクロフト糸状虫	フィラリア症/糸状虫症	アカイエカ	リンパ系	急性期：リンパ肝炎、リンパ腺炎を伴う熱発作(filarial fever) 慢性期：乳糜尿、リンパ管瘤、陰嚢水腫、象皮病	急性期：夜間のmicrofilariaの検出慢性期：特有の症状を考慮	diethylcarbamazine & ivermectin
	Brugia malayi	マレー糸状虫	フィラリア症/糸状虫症	アカイエカ	リンパ系		急性期：夜間のmicrofilariaの検出慢性期：特有の症状を考慮	diethylcarbamazine & ivermectin
	Dirofilaria immitis	イヌ糸状虫		アカイエカ	なし	幼虫移行症→肺血管閉塞→胸部X線画像銭形陰影
	Gnathostoma spinigerum	有棘顎口虫	顎口虫症	ドジョウ、雷魚、ヘビの生食		消化管壁貫通→皮下移動による腫瘤や線状皮膚炎	移動性腫瘤、皮膚爬行疹雷魚やドジョウの生殖の問診免疫血清診断	なし
	Gnathostoma hispidum	剛棘顎口虫
	Gnathostoma doloresi	ドロレス顎口虫
	Gnathostoma nipponicum	日本顎口虫
	Anisakis simplex, larva	アニキサス幼虫	アニサキス症 (1)胃アニサキス症、 (2)腸アニサキス症、 (3)異所性アニサキス症	経口感染終宿主：クジラ、イルカ。中間宿主：オキアミ。待機宿主：サバ、ニシン、アジ、タラなど	胃や腸	(1)急激な上腹部痛"胃けいれん" (2)腹痛、急性虫垂炎、イレウス様。劇症型と緩和型がある (3)腹腔内の炎症性肉芽腫	胃内視鏡検査	内視鏡による虫体摘出
	Pseudoterranova decipiens	アニキサス幼虫	アニサキス症 (1)胃アニサキス症、 (2)腸アニサキス症、 (3)異所性アニサキス症	経口感染終宿主：クジラ、イルカ。中間宿主：オキアミ。待機宿主：サバ、ニシン、アジ、タラなど	胃や腸		胃内視鏡検査	内視鏡による虫体摘出
	Trichinella spiralis	旋毛虫	旋毛虫症	経口感染豚肉、クマ肉の生食		(1)成虫侵襲期：下痢、腹痛 (2)幼虫筋肉移行期：顔面浮腫、心筋障害など (3)幼虫被嚢期：全身浮腫、衰弱		急性期：ステロイド殺虫：mebendazole
			鞭虫症		盲腸	慢性下痢、腹痛、異食症、貧血	セロファン重層塗沫法、ホルマリンエーテル法	mebendazole
	Spirurin nematode larva	旋尾線虫	旋尾線虫幼虫	ホタルイカの生食	なし	皮膚爬行疹、イレウス様症状	予防：-30℃24時間。生食には-30℃4日間以上	摘出
吸虫類	Shistosoma japonicum	日本住血吸虫	日本住血吸虫症	糞便虫の虫卵→ミラシジウム→ ミヤイリガイ体内でセルカリア→ 人畜の皮膚より浸入→循環系→ 門脈に寄生	門脈	(1)潜伏期：侵入部の掻痒性皮膚炎。肺移行期：咳、発熱 (2)急性期：虫卵の門脈系寄生、産卵。住血吸虫性赤痢。 (3)慢性期：虫卵の肝、脳などの塞栓。肝硬変。脾腫、腹水	糞便虫の虫卵の検出。直腸粘膜層掻爬法、肝穿刺による組織内虫卵の検出。補助診断として免疫血清学的検査。	praziquantel
	Paragonimus westermani	ウェステルマン肺吸虫	肺吸虫症/肺ジストマ症	経口感染淡水産のカニ、イノシシ肉の生食	肺	痰、咳、胸痛、時に喀血	痰や便の虫卵検査、胸部写真、断層写真で明らかな虫嚢。免疫学血清検査
	Paragonimus miyazakii	宮崎肺吸虫	肺吸虫症/肺ジストマ症	経口感染淡水産のカニ、イノシシ肉の生食	肺	気胸、胸水貯留、膿胸、好酸球増加		praziquantel
	Clonorchis sinensis	肝吸虫	肝吸虫症/肝ジストマ症	経口感染虫卵→(マメタニシ:セルカリア)→ セルカリア→(魚:メタセルカリア)→ 摂取→(ヒト:成虫)→虫卵	胆管	胆汁流出障害による肝障害→肝硬変	糞便、胆汁(十二指腸ゾンデ法)。肝吸虫卵の検出。CT像。エコー検査。	praziquantel
			横川吸虫症	淡水魚(アユ、フナ、ウグイ、シラウオ)の生食	小腸粘膜	下痢、腹痛	糞便虫の虫卵	praziquantel
条虫類	Taeniarhynchus saginatus	無鉤条虫	腸管条虫症	経口感染。中間宿主：ウシ	小腸	無症状。下痢。広節裂頭条虫感染では悪性貧血。	糞便虫の虫卵と体節により診断	praziquantel。有鉤条虫の場合はガストログラフィン。有鉤条虫の駆虫の際、虫体を破壊しない →虫体の融解による嚢虫症
	Taenia solium	有鉤条虫		経口感染。中間宿主：ブタ
	Diphyllobothrium latum	広節裂頭条虫		経口感染。中間宿主：サケ、マス
		日本海裂頭条虫		経口感染。中間宿主：サケ
			腸管外条虫症
			有鉤嚢虫症	有鉤条虫の虫卵の経口摂取	皮下、筋肉内脳、脊髄、眼球	皮下、筋肉内：小指頭大の無症状腫瘤脳、脊髄、眼球：Jacksonてんかん。痙性麻痺など	皮下の虫嚢	外科的摘出。成虫寄生がなければ、praziquantel, albendazole + ステロイド
	Echinococcus granulosus	単包虫	包虫症/ エキノコックス症 (単包虫症)	終宿主：イヌ、キツネなど。中間宿主：ヒト、ブタ、野ネズミなど。終宿主の糞便虫の虫卵を中間宿主が接種して発症	肝、肺、まれに脳、腎、筋肉	肝寄生：肝部疼痛、満腹、時に黄疸、下肢浮腫肺寄生：胸部圧迫感、胸痛、咳、血痰、時に喀血	肝や肺の嚢胞形成から疑う。早期に診断に皮内反応→ CT、エコー→ 生検。免疫血清学的診断法	外科的切除。 albendazoleの長期投与
	Echinococcus multilocularis	多包虫	包虫症/ エキノコックス症 (多包虫症)	終宿主：イヌ、キツネなど。中間宿主：ヒト、ブタ、野ネズミなど。終宿主の糞便虫の虫卵を中間宿主が接種して発症	肝、肺、まれに脳、腎、筋肉	肝寄生：肝部疼痛、満腹、時に黄疸、下肢浮腫肺寄生：胸部圧迫感、胸痛、咳、血痰、時に喀血	肝や肺の嚢胞形成から疑う。早期に診断に皮内反応→ CT、エコー→ 生検。免疫血清学的診断法	外科的切除。 albendazoleの長期投与