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type genus of the family Schistosomatidae: blood flukes (同)genus Schistosoma

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/05/22 07:07:20」(JST)

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 traverse 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 antigens.<ref name="Black 2005">Black, J. (2005). Microbiology: Principles and Explorations. Wiley, New York. </ref> 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<ref name="Black 2005"/> (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.<ref>Roberts, L., Janovy, J. (1996). Foundations of Parasitology, 5th edition. Wm. C. Brown Publishers, Dubuque, Iowa. </ref>

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 Black, J. (2005). Microbiology: Principles and Explorations. Wiley, New York.

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1. 住血吸虫症の疫学、病因、および臨床症状 epidemiology pathogenesis and clinical manifestations of schistosomiasis
2. 膀胱腫瘍の病理 pathology of bladder neoplasms
3. 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
4. 非尿路上皮膀胱癌 non urothelial bladder cancer
5. 住血吸虫症および糸球体疾患 schistosomiasis and glomerular disease

English Journal

Regulation of laboratory populations of snails (Biomphalaria and Bulinus spp.) by river prawns, Macrobrachium spp. (Decapoda, Palaemonidae): Implications for control of schistosomiasis.

Sokolow SH1, Lafferty KD2, Kuris AM3.Author information 1Ecology Evolution and Marine Biology Department, University of California Santa Barbara, Santa Barbara, CA, 93106, USA. Electronic address: ssokolow@stanford.edu.2Western Ecological Research Center, US Geological Survey, c/o Marine Science Institute, University of California, Santa Barbara, CA, 93106, USA.3Ecology Evolution and Marine Biology Department, University of California Santa Barbara, Santa Barbara, CA, 93106, USA.AbstractHuman schistosomiasis is a common parasitic disease endemic in many tropical and subtropical countries. One barrier to achieving long-term control of this disease has been re-infection of treated patients when they swim, bathe, or wade in surface fresh water infested with snails that harbor and release larval parasites. Because some snail species are obligate intermediate hosts of schistosome parasites, removing snails may reduce parasitic larvae in the water, reducing re-infection risk. Here, we evaluate the potential for snail control by predatory freshwater prawns, Macrobrachium rosenbergii and M. vollenhovenii, native to Asia and Africa, respectively. Both prawn species are high value, protein-rich human food commodities, suggesting their cultivation may be beneficial in resource-poor settings where few other disease control options exist. In a series of predation trials in laboratory aquaria, we found both species to be voracious predators of schistosome-susceptible snails, hatchlings, and eggs, even in the presence of alternative food, with sustained average consumption rates of 12% of their body weight per day. Prawns showed a weak preference for Bulinus truncatus over Biomphalaria glabrata snails. Consumption rates were highly predictable based on the ratio of prawn: snail body mass, suggesting satiation-limited predation. Even the smallest prawns tested (0.5-2g) caused snail recruitment failure, despite high snail fecundity. With the World Health Organization turning attention toward schistosomiasis elimination, native prawn cultivation may be a viable snail control strategy that offers a win-win for public health and economic development.
Acta tropica.Acta Trop.2014 Apr;132:64-74. doi: 10.1016/j.actatropica.2013.12.013. Epub 2013 Dec 31.
Human schistosomiasis is a common parasitic disease endemic in many tropical and subtropical countries. One barrier to achieving long-term control of this disease has been re-infection of treated patients when they swim, bathe, or wade in surface fresh water infested with snails that harbor and rele
PMID 24388955

Comparative evaluation of Schistosoma mansoni, Schistosoma intercalatum, and Schistosoma haematobium alkaline phosphatase antigenicity by the alkaline phosphatase immunoassay (APIA).

Cesari IM1, Ballén DE, Mendoza L, Ferrer A, Pointier JP, Kombila M, Richard-Lenoble D, Théron A.Author information 1Centro de Microbiología y Biología Celular, Instituto Venezolano de Investigaciones Científicas (IVIC), Apdo. 21827, Caracas, 1020 A, Venezuela.AbstractTo know if alkaline phosphatase (AP) from schistosomes other than Schistosoma mansoni can be used as diagnostic marker for schistosomiasis in alkaline phosphatase immunocapture assay (APIA), we comparatively tested n-butanol extracts of adult worm membranes from a Venezuelan (JL) strain of S. mansoni (Ven/AWBE/Sm); a Cameroonian (EDEN) strain of Schistosoma intercalatum (Cam/AWBE/Si) and a Yemeni strain of Schistosoma haematobium (Yem/AWBE/Sh). APIA was evaluated with sera of patients from Venezuela, Senegal, and Gabon infected with S. mansoni, from Gabon infected with S. intercalatum or S. haematobium, from Chine infected with Schistosoma japonicum and from Cambodian patients infected with Schistosoma mekongi. Results indicate that 92.5 % (37/40) of Venezuela sera, 75 % (15/20) of Senegal sera, 39.5 % (17/43) of S. haematobium sera, and 19.2 % (5/26) S. intercalatum sera were APIA-positive with the Ven/AWBE/Sm preparation. APIA with the Cam/AWBE/Si preparation showed that 53.8 % of S. intercalatum-positive sera had anti-AP antibodies, and 51.2 % S. haematobium-positive sera cross-immunocapturing the S. intercalatum AP. APIA performed with Yem/AWBE/Sh showed that 55.8 % S. haematobium sera were positive. Only two out of nine S. japonicum sera were APIA-positive with the Ven/AWBE/Sm and Cam/AWBE/Si, and no reaction was observed with Cambodian S. mekongi-positive sera. AP activity was shown to be present in all the schistosome species/strains studied. The use of APIA as a tool to explore the APs antigenicity and the presence of Schistosoma sp. infections through the detection of anti-Schistosoma sp. AP antibodies in a host, allowed us to demonstrate the antigenicity of APs of S. mansoni, S. intercalatum, and S. haematobium.
Parasitology research.Parasitol Res.2014 Apr;113(4):1395-403. doi: 10.1007/s00436-014-3780-5. Epub 2014 Jan 23.
To know if alkaline phosphatase (AP) from schistosomes other than Schistosoma mansoni can be used as diagnostic marker for schistosomiasis in alkaline phosphatase immunocapture assay (APIA), we comparatively tested n-butanol extracts of adult worm membranes from a Venezuelan (JL) strain of S. manson
PMID 24452918

Comparing parasitological vs serological determination of Schistosoma haematobium infection prevalence in preschool and primary school-aged children: implications for control programmes.

Wami WM1, Nausch N1, Bauer K1, Midzi N2, Gwisai R3, Simmonds P4, Mduluza T5, Woolhouse M4, Mutapi F1.Author information 1Institute of Immunology & Infection Research, University of Edinburgh, Ashworth Laboratories, King's Buildings, West Mains Rd, Edinburgh EH9 3JT, UK.2National Institute of Health Research, P.O. Box CY 573, Causeway, Harare, Zimbabwe.3Ministry of Health and Child Care, Murewa District Hospital, P.O. Box 60, Murewa, Zimbabwe.4Centre for Immunity, Infection & Evolution, University of Edinburgh, Ashworth Laboratories, King's Buildings, West Mains Rd, Edinburgh EH9 3JT, UK.5University of Zimbabwe, Biochemistry Department, P.O. Box MP167, Mount Pleasant, Harare, Zimbabwe.AbstractSUMMARY To combat schistosomiasis, the World Health Organization (WHO) recommends that infection levels are determined prior to designing and implementing control programmes, as the treatment regimens depend on the population infection prevalence. However, the sensitivity of the parasitological infection diagnostic method is less reliable when infection levels are low. The aim of this study was to compare levels of Schistosoma haematobium infection obtained by the parasitological method vs serological technique. Infection levels in preschool and primary school-aged children and their implications for control programmes were also investigated. Infection prevalence based on serology was significantly higher compared with that based on parasitology for both age groups. The difference between infection levels obtained using the two methods increased with age. Consequentially, in line with the WHO guidelines, the serological method suggested a more frequent treatment regimen for this population compared with that implied by the parasitological method. These findings highlighted the presence of infection in children aged ⩽5 years, further reiterating the need for their inclusion in control programmes. Furthermore, this study demonstrated the importance of using sensitive diagnostic methods as this has implications on the required intervention controls for the population.
Parasitology.Parasitology.2014 Mar 28:1-9. [Epub ahead of print]
SUMMARY To combat schistosomiasis, the World Health Organization (WHO) recommends that infection levels are determined prior to designing and implementing control programmes, as the treatment regimens depend on the population infection prevalence. However, the sensitivity of the parasitological infe
PMID 24679476

Japanese Journal

Risk Factors and Spatial Distribution of Schistosoma mansoni Infection among Primary School Children in Mbita District, Western Kenya

Nagi Sachiyo,Chadeka Evans A.,Sunahara Toshihiko,Mutungi Faith,Justin Yombo K. Dan,Kaneko Satoshi,Ichinose Yoshio,Matsumoto Sohkichi,Njenga Sammy M.,Hashizume Masahiro,Shimada Masaaki,Hamano Shinjiro
PLoS Neglected Tropical Diseases 8(7), e2991, 2014-07-24
… Background:An increasing risk of Schistosoma mansoni infection has been observed around Lake Victoria, western Kenya since the 1970s. … haematobium. …
NAID 120005477035

アフリカの中間宿主貝について

野田伸一
衞生動物 63(4), 283-288, 2012-12-30
NAID 10031131472

アフリカの住血吸虫症

嶋田雅曉
衞生動物 63(4), 277-282, 2012-12-30
NAID 10031131471

Related Pictures

★リンクテーブル★

リンク元	「ビルハルツ住血吸虫」

「ビルハルツ住血吸虫」

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)

ビルハルツ住血吸虫
	膀胱内のビルハルツ住血吸虫の卵
分類
学名
	Schistosoma haematobium (Bilharz, 1852) Weinland, 1858
和名
	ビルハルツ住血吸虫

　　[★]

ラ: Schistosoma haematobium(Bilharz, 1852) Weinland, 1858
関: 住血吸虫症、蠕虫

-Schistosoma haematobium

[kiseichu-1] 日本寄生虫学会用語委員会「暫定新寄生虫和名表」 2008年5月22日

[1] 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.

[2] 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.

[Black_2005-3] Black, J. (2005). Microbiology: Principles and Explorations. Wiley, New York.

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案内

Schistosoma haematobium