関: bilharziasis、schistosomiasis、urinary schistosomiasis

WordNet

an infestation with or a resulting infection caused by a parasite of the genus Schistosoma; common in the tropics and Far East; symptoms depend on the part of the body infected (同)bilharzia, bilharziasis
European genus of bloodsucking flies (同)genus Haematobia

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/07/13 02:36:03」(JST)

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Schistosoma haematobium is an important digenetic trematode, and is found in Africa and the Middle East. It is a major agent of schistosomiasis; more specifically, it is associated with urinary schistosomiasis.

Adults are found in the Venous plexuses around the urinary bladder and the released eggs travels to the wall of the urine bladder causing haematuria and fibrosis of the bladder. The bladder becomes calcified, and there is increased pressure on ureters and kidneys otherwise known as hydronephrosis. Inflammation of the genitals due to S. haematobium may contribute to the propagation of HIV.^[1] Studies have shown the relationship between S. haematobium infection and the development of squamous cell carcinoma of the bladder.^[2]

Life cycle

The free swimming infective larval cercariae burrow into human skin when it comes into contact with contaminated water. The cercariae enter the blood stream of the host where they travel to the liver to mature into adult flukes. In order to avoid detection by the immune system inside the host, the adults have the ability to coat themselves with host antigen^[3] After a period of about three weeks the young flukes migrate to the urinary bladder veins to copulate. The female fluke lays as many as 30 eggs per day which migrate to the lumen of the urinary bladder and ureters. The eggs are eliminated from the host into the water supply with micturition. In fresh water, the eggs hatch forming free swimming miracidia which penetrate into the intermediate snail host^[3] (Bulinus spp., e.g. B. globosus, B. forskalii, B. nyassanus and B. truncatus). Inside the snail, the miracidium sheds it epithelium and develops into a mother sporocyst. After two weeks the mother begins forming daughter sporocysts. Four weeks after the initial penetration of the miracardium into the snail furcocercous cercariae begin to be released. The cercariae cycle from the top of the water to the bottom for three days in the search of a human host. Within half an hour the cercariae enter the host epithelium.^[4]

Diagnosis

The majority of diagnoses are made by examination of the urine for eggs. In chronic infections, or if eggs are difficult to find, an intradermal injection of schistosome antigen to form a wheal is effective in determining infection. Alternate diagnosis can be made by complement fixation tests.^[3]

Prevention

The main cause of schistomiasis is the dumping of human waste into water supplies. Hygienic disposal of waste would be sufficient to eliminate the disease.^[3]

Immunopathology

The immune system responds to eggs in liver causing hypersensitivity; an immune response is necessary to prevent damage to hepatocytes. The hosts' antibodies which bind to the tegument of the Schistosome don't bind for long since the tegument is shed every few hours. The schistosome can also take on host proteins. Schistomiasis can be divided into three phases: (1) the migratory phase lasting from penetration to maturity,(2) the acute phase which occurs when the schistosomes begin producing eggs, and (3) the chronic phase which occurs mainly in endemic areas.^[3]

Pathology

The ova are initially deposited in the muscularis propria which leads to ulceration of the overlaying tissue. Infections are characterized by pronounced acute inflammation, squamous metaplasia, blood and reactive epithelial changes. Granulomas and multinucleated giant cells may be seen.

Treatment

The drug of choice is praziquantel, a quinolone derivative.

References

^ Leutscher PD, Pedersen M, Raharisolo C et al. (2005). "Increased prevalence of leukocytes and elevated cytokine levels in semen from Schistosoma haematobium-infected individuals". J Infect Dis 191 (10): 1639–47. doi:10.1086/429334. PMID 15838790.
^ Khurana S, Dubey ML, Malla N (April 2005). "Association of parasitic infections and cancers". Indian J Med Microbiololgy 23 (2): 74–79. doi:10.1016/S0300-483X(01)00357-2.
^ ^a ^b ^c ^d ^e Black, J. (2005). Microbiology: Principles and Explorations. Wiley, New York.
^ Roberts, L., Janovy, J. (1996). Foundations of Parasitology, 5th edition. Wm. C. Brown Publishers, Dubuque, Iowa.

UpToDate Contents

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1. 住血吸虫症の診断 diagnosis of schistosomiasis
2. 住血吸虫症の治療および予防 treatment and prevention of schistosomiasis
3. 住血吸虫症の疫学、病因、および臨床症状 epidemiology pathogenesis and clinical manifestations of schistosomiasis
4. 中央アフリカへの旅行によって感染する可能性のある疾患 diseases potentially acquired by travel to central africa
5. 住血吸虫症および糸球体疾患 schistosomiasis and glomerular disease

English Journal

IMAGES IN CLINICAL MEDICINE. Eggshell Calcifications of the Bladder.

Nepal P1, Kumar D1.
The New England journal of medicine.N Engl J Med.2016 Feb 25;374(8):e9. doi: 10.1056/NEJMicm1504759.
PMID 26933870

[Removal of weremit from the abdomen. Interpretation and efficacy of an ancient Egyptian prescription by the newest scientific results].

Katona J1, Győry H2, Blázovics A1.
Orvosi hetilap.Orv Hetil.2015 Dec 13;156(50):2045-51. doi: 10.1556/650.2015.30285.
Significant percentage of today's knowledge of ancient Egyptian medicine has been acquired from papyri left behind from various periods of Egyptian history. The longest and the most comprehensive is the Ebers papyrus, kept at the University Museum of Leipzig, which was written more than one thousand
PMID 26639646

DICROCOELIUM DENDRITICUM INFECTION IN A PATIENT WITH CHRONIC SCHISTOSOMIASIS HAEMATOBIUM.

Ella OH, Mohammad AE.
Journal of the Egyptian Society of Parasitology.J Egypt Soc Parasitol.2015 Dec;45(3):629-32.
Infection with Dicrocoelium dendriticum in humans is seldom to be reported in Egypt. This liver fluke, which commonly infects ruminants, has a complex life cycle with two intermediate hosts; the land snail and the ant. Human infection occurs by accidental ingestion of the second intermediate host. T
PMID 26939241

Japanese Journal

Effect of communal piped water supply on pattern of water use and transmission of schistosomiasis haematobia in an endemic area of Kenya

ABE Mayumi,MUHOHO Ngethe D.,SUNAHARA Toshihiko,MOJI Kazuhiko,YAMAMOTO Taro,AOKI Yoshiki
Tropical medicine and health 37(2), 43-53, 2009-06-01
… An attempt was made to examine the long-term impact of the introduction of communal piped water supply on pattern of water use and transmission of schistosomiasis haematobia in an endemic area of Kenya. …
NAID 10025715100

無症候群ビルハルツ住血吸虫症:輸入症例としての1例

大西健児
日本熱帯医学会雑誌 25(4), 215-216, 1997-12-15
NAID 10011490580

Cercarial Density in the River of an Endemic Area of Schistosomiasis Haematobia in Kenya

Muhoho Ngethe D.,Katsumata Tatsuya,Kimura Eisaku,Migwi David K.,Mutua Wilfred R.,Kiliku Francis M.,Habe Shigehisa,Aoki Yoshiki
American Journal of Tropical Medicine and Hygiene 57(2), 162-167, 1997-08
… The cercarial density in natural water and number of infected Bulinus globosus were monitored over a one-year period to identify the transmission foci in an endemic area of schistosomiasis haematobia in Kenya. … Cercariometry and snail sampling remain quite complementary in identifying the transmission foci of schistosomiasis. …
NAID 120001269754

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★リンクテーブル★

リンク元	「bilharziasis」「ビルハルツ住血吸虫症」「urinary schistosomiasis」

「bilharziasis」

Schistosoma haematobium
	Histopathology of bladder shows eggs of Schistosoma haematobium surrounded by intense infiltrates of eosinophils.
Scientific classification
Kingdom:	Animalia
Phylum:	Platyhelminthes
Class:	Trematoda
Subclass:	Digenea
Order:	Prosostomata
Family:	Schistosomatoidea
Genus:	Schistosoma
Species:	S. haematobium
Binomial name
	Schistosoma haematobium; (Bilharz, 1852)