Schistosomiasis
Classification & external resources

Skin vesicles created by the penetration of Schistosoma. Source: CDC
ICD-10	B65.
ICD-9	120
MeSH	D012552

Schistosomiasis or bilharzia is a parasitic disease caused by several species of flatworm. The acute form of schistosomiasis is sometimes known as snail fever and cutaneous schistosomiasis is sometimes commonly called swimmer's itch. The disease affects many people in developing countries, and in certain African communities and east Asia, the process of overcoming schistosomiasis is an important rite of passage. Although it has a low mortality rate, schistosomiasis can be very debilitating. Schistosomiasis is known as Bilharzia or bilharziosis in many countries, after Theodor Bilharz, who first described the cause of urinary schistosomiasis in 1851, although the first doctor who described entirely the disease cycle was Pirajá da Silva in 1908. Schistosome dermatitis, or swimmers itch” occurs when skin is penetrated by a free-swimming, fork-tailed infective cercaria. ... The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10) is a coding of diseases and signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or diseases, as classified by the World Health Organization (WHO). ... // A00-A79 - Bacterial infections, and other intestinal infectious diseases, and STDs (A00-A09) Intestinal infectious diseases (A00) Cholera (A01) Typhoid and paratyphoid fevers (A010) Typhoid fever (A02) Other Salmonella infections (A03) Shigellosis (A04) Other bacterial intestinal infections (A040) Enteropathogenic Escherichia coli infection (A045) Campylobacter enteritis (A046) Enteritis due to Yersinia... The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. ... Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. ... A parasitic disease is a disease caused or transmitted by a parasite. ... Classes Monogenea Trematoda Cestoda Turbellaria Wikimedia Commons has media related to: Platyhelminthes Wikispecies has information related to: Platyhelminthes The flatworms (Phylum Platyhelminthes from the Greek platy, meaning flat and helminth, meaning worm) are a phylum of relatively simple soft-bodied invertebrate animals. ... Swimmer’s itch, or cercarial dermatitis, is a short-term, immune reaction occurring in the skin of humans that have been infected by water-borne trematode parasites. ... East Asia Geographic East Asia. ... For other uses, see Rite of passage (disambiguation). ... Crude death rate by country Mortality rate is a measure of the number of deaths (in general, or due to a specific cause) in some population, scaled to the size of that population, per unit time. ... Theodor Bilharz (March 23, 1825 – May 9, 1862) was a German physician and an important pioneer in the field of parasitology. ... Manuel Augusto Pirajá da Silva (Camamu, Bahia, Brazil 1873 — Salvador, Bahia, Brazil 1961) was a Brazilian parasitologist, researcher and doctor. ...

An often chronic illness that results from infection of the blood with a parasitic flatworm (schistosome), it causes debilitation and causes liver and intestinal damage. It is most commonly found in Asia, Africa, and South America, especially in areas with water that is contaminated with fresh water snails, which contain the parasite.

Types

There are five species of flatworms that cause schistosomiasis. Each causes a different clinical presentation of the disease. Schistosomiasis may localize in different parts of the body, and its localization determines its particular clinical profile. This article is about the medical term. ...

• Schistosoma mansoni (ICD-10 B65.1) and Schistosoma intercalatum (B65.8) cause intestinal schistosomiasis
• Schistosoma haematobium (B65.0) causes urinary schistosomiasis
• Schistosoma japonicum (B65.2) and Schistosoma mekongi (B65.8) cause Asian intestinal schistosomiasis

Binomial name Schistosoma mansoni Sambon, 1907 Schistosoma mansoni is an important human parasite. ... The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... Species Schistosoma intercalatum Schistosoma intercalatum is an important parasite. ... The intestine is the portion of the alimentary canal extending from the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine. ... Binomial name Schistosoma haematobium (Bilharz, 1852) Schistosoma haematobium is an important parasite. ... This article is about the urine of animals generally. ... Binomial name Schistosoma japonicum (Katsurada, 1904) Schistosoma japonicum is an important parasite and one of the major infectious agents of schistosomiasis. ... Species Schistosoma mekongi Schistosoma mekongi is an important parasite. ... For other uses, see Asia (disambiguation). ...

Geographical distribution and epidemiology

The disease is found in tropical countries in Africa, Caribbean, eastern South America, east Asia and in the Middle East. Schistosoma mansoni is found in parts of South America and the Caribbean, Africa, and the Middle East; S. haematobium in Africa and the Middle East; and S. japonicum in the Far East. S. mekongi and S. intercalatum are found focally in Southeast Asia and central West Africa, respectively. A tropic is either of two circles of latitude: Tropic of Cancer, at 23½°N Tropic of Capricorn, at 23½°S Tropic is also the name of a town in Utah, United States. ... A world map showing the continent of Africa Africa is the worlds second-largest and second most-populous continent, after Asia. ... West Indies redirects here. ... South America South America is a continent crossed by the equator, with most of its area in the Southern Hemisphere. ... For other uses, see Asia (disambiguation). ... A map showing countries commonly considered to be part of the Middle East The Middle East is a region comprising the lands around the southern and eastern parts of the Mediterranean Sea, a territory that extends from the eastern Mediterranean Sea to the Persian Gulf. ... Binomial name Schistosoma mansoni Sambon, 1907 Schistosoma mansoni is an important human parasite. ... The far east as a cultural block includes East Asia, Southeast Asia, Northeast Asia and South Asia. ... Location of Southeast Asia Southeast Asia is a subregion of Asia. ...  Western Africa (UN subregion)  Maghreb[1] West Africa or Western Africa is the westernmost region of the African continent. ...

An estimated 207 million people have the disease, 120 million symptomatic. A few countries have eradicated the disease, and many more are working towards it. The World Health Organization is promoting efforts working towards this goal. In some cases, urbanization, pollution, and/or consequent destruction of snail habitat has reduced exposure, with a subsequent decrease in new infections. The most common way of getting schistosomiasis in developing countries is by wading or swimming in lakes, ponds and other bodies of water which are infested with the snails (usually of the Biomphalaria, Bulinus, or Oncomelania genus) that are the natural reservoirs of the Schistosoma pathogen. WHO redirects here. ... For other uses, see Snail (disambiguation). ... Species Species Biomphalaria glabrata Species Biomphalaria obstructa Species Biomphalaria amazonica Species Biomphalaria pfeifferi Species Biomphalaria tenagophila Species Biomphalaria havanensis Species Biomphalaria straminea Species Biomphalaria alexandrina Species Biomphalaria subprona Biomphalaria is an important genus of snail that serves as a natural host for the schistomasomiasis blood fluke. ... [[{{{diversity_link}}}|Diversity]] {{{diversity}}} Binomial name {{{binomial}}} Trinomial name {{{trinomial}}} Type Species {{{type_species}}} {{{subdivision_ranks}}} [[Image:{{{range_map}}}|{{{range_map_width}}}|]] Synonyms {{{synonyms}}} Bulinus is an important genus of fresh-water snail. ... Genera Genus Oncomelania Oncomelania is a genus of snail. ... Natural reservoir or nidus, refers to the long-term host of the pathogen of an infectious disease. ...

Life cycle

Schistosomiasis life cycle. Source: CDC

Schistosomes have a typical trematode vertebrate-invertebrate lifecycle, with humans being the definitive host. The life cycles of all five human schistosomes are broadly similar: parasite eggs are released into the environment from infected individuals, hatching on contact with fresh water to release the free-swimming miracidium. Miracidia infect fresh-water snails by penetrating the snail's foot. After infection, close to the site of penetration, the miracidium transforms into a primary (mother) sporocyst. Germ cells within the primary sporocyst will then begin dividing to produce secondary (daughter) sporocysts, which migrate to the snail's hepatopancreas. Once at the hepatopancreas, germ cells within the secondary sporocyst begin to divide again, this time producing thousands of new parasites, known as cercariae, which are the larvae capable of infecting mammals. Life cycle of schistomiasis parasite. ... Life cycle of schistomiasis parasite. ... Orders not necessarily a complete list Azygiida Echinostomida Opisthorchiida Plagiorchiida Strigeata Strigeatida Trematodes are also known as flukes. ... The miracidium is the free swimming larva of some Trematoda including the Schistosoma. ... Giant African Snail (Achatina fulica) The name snail applies to most members of the molluscan Class Gastropoda that have coiled shells. ... Histology section of hepatopancreas of slug Deroceras laeve. ... The miracidium is the small free-swimming larva of some Trematoda including the Schistosoma. ...

Cercariae emerge daily from the snail host in a circadian rhythm, dependent on ambient temperature and light. Young cercariae are highly motile, alternating between vigorous upward movement and sinking to maintain their position in the water. Cercarial activity is particularly stimulated by water turbulence, by shadows and by chemicals found on human skin. Penetration of the human skin occurs after the cercaria have attached to and explored the skin. The parasite secretes enzymes that break down the skin's protein to enable penetration of the cercarial head through the skin. As the cercaria penetrates the skin it transforms into a migrating schistosomulum stage. The circadian rhythm is a name given to the internal body clock that regulates the (roughly) 24 hour cycle of biological processes in animals and plants. ...

The newly transformed schistosomulum may remain in the skin for 2 days before locating a post-capillary venule; from here the schistosomulum travels to the lungs where it undergoes further developmental changes necessary for subsequent migration to the liver. Eight to ten days after penetration of the skin, the parasite migrates to the liver sinusoids. S. japonicum migrates more quickly than S. mansoni, and usually reaches the liver within 8 days of penetration. Juvenile S. mansoni and S. japonicum worms develop an oral sucker after arriving at the liver, and it is during this period that the parasite begins to feed on red blood cells. The nearly-mature worms pair, with the longer female worm residing in the gynaecophoric channel of the shorter male. Adult worms are about 10 mm long. Worm pairs of S. mansoni and S. japonicum relocate to the mesenteric or rectal veins. S. haematobium schistosomula ultimately migrate from the liver to the perivesical venous plexus of the bladder, ureters, and kidneys through the hemorrhoidal plexus. A venule is a small blood vessel that allows deoxygenated blood to return from the capillary beds to the larger blood vessels called veins. ... Sinusoid of a rat liver with fenestrated endothelial cells. ... In anatomy, a mesentery is a part of the peritoneum that connects an internal organ, such as the small intestine, to the abdominal wall. ...

Parasites reach maturity in six to eight weeks, at which time they begin to produce eggs. Adult S. mansoni pairs residing in the mesenteric vessels may produce up to 300 eggs per day during their reproductive lives. S. japonicum may produce up to 3000 eggs per day. Many of the eggs pass through the walls of the blood vessels, and through the intestinal wall, to be passed out of the body in faeces. S. haematobium eggs pass through the ureteral or bladder wall and into the urine. Only mature eggs are capable of crossing into the digestive tract, possibly through the release of proteolytic enzymes, but also as a function of host immune response, which fosters local tissue ulceration. Up to half the eggs released by the worm pairs become trapped in the mesenteric veins, or will be washed back into the liver, where they will become lodged. Worm pairs can live in the body for an average of four and a half years, but may persist up to 20 years. Proteolysis is the directed degradation (digestion) of proteins by cellular enzymes called proteases or by intramolecular digestion. ...

Trapped eggs mature normally, secreting antigens that elicit a vigorous immune response. The eggs themselves do not damage the body. Rather it is the cellular infiltration resultant from the immune response that causes the pathology classically associated with schistosomiasis. An antigen is any molecule that is recognized by antibodies. ... A request has been made on Wikipedia for this article to be deleted in accordance with the deletion policy. ...

Pathology

Above all, schistosomiasis is a chronic disease. Pathology of S. mansoni and S. japonicum schistosomiasis includes: Katayama fever, hepatic perisinusoidal egg granulomas, Symmers’ pipe stem periportal fibrosis, portal hypertension, and occasional embolic egg granulomas in brain or spinal cord. Pathology of S. haematobium schistosomiasis includes: hematuria, scarring, calcification, squamous cell carcinoma, and occasional embolic egg granulomas in brain or spinal cord. Bladder Cancer diagnosis and mortality are generally elevated in affected areas. Medicine In medicine, a persistent and lasting condition is said to be chronic (from Greek chronos). ... Katayama fever is another name for schistosomiasis, caused by one of the members of the Schistosoma species. ... In medicine (anatomical pathology), a granuloma is a group of epithelioid macrophages surrounded by a lymphocyte cuff. ... In medicine, portal hypertension is hypertension (high blood pressure) in the portal vein and its branches. ... An embolism occurs when an object (the embolus, plural emboli) migrates from one part of the body (through circulation) and cause(s) a blockage (occlusion) of a blood vessel in another part of the body. ... The human brain In animals, the brain (enkephalos) (Greek for in the skull), is the control center of the central nervous system, responsible for behavior. ... The Spinal cord nested in the vertebral column. ... In medicine, hematuria (or haematuria) is the presence of blood in the urine. ... This article does not cite any references or sources. ... Dystrophic calcification is the mineralization of soft tissue without a systemic mineral imbalance. ... Biopsy of a highly differentiated squamous cell carcinoma of the mouth. ... Bladder cancer refers to any of several types of malignant growths of the urinary bladder. ...

Clinical features

Many infections are subclinically symptomatic, with mild anemia and malnutrition being common in endemic areas. Acute schistosomiasis (Katayama's fever) may occur weeks after the initial infection, especially by S. mansoni and S. japonicum. Manifestations include:

• Abdominal pain
• Cough
• Diarrhea
• Eosinophilia - extremely high eosinophil granulocyte count.
• Fever
• Fatigue
• Hepatosplenomegaly - the enlargement of both the liver and the spleen.

Occasionally central nervous system lesions occur: cerebral granulomatous disease may be caused by ectopic S. japonicum eggs in the brain, and granulomatous lesions around ectopic eggs in the spinal cord from S. mansoni and S. haematobium infections may result in a transverse myelitis with flaccid paraplegia. Continuing infection may cause granulomatous reactions and fibrosis in the affected organs, which may result in manifestations that include: Abdominal pain can be one of the symptoms associated with transient disorders or serious disease. ... Diarrhea, also spelled diarrhoea (see spelling differences), is a condition in which the sufferer has frequent watery, loose bowel movements (from the Greek word διάρροια; literally meaning through-flowing). Acute infectious diarrhea is a common cause of death in developing countries (particularly among infants), accounting for 5 to 8 million deaths... Eosinophilia is the state of having high eosinophil granulocytes in the blood. ... Image of an eosinophil Eosinophil granulocytes, commonly referred to as eosinophils (or less commonly as acidophils), are white blood cells of the immune system that are responsible for combating infection by parasites in vertebrates. ... An analogue medical thermometer showing the temperature of 38. ... The word fatigue is used in everyday living to describe a range of afflictions, varying from a general state of lethargy to a specific work induced burning sensation within muscle. ... Hepatosplenomegaly is the simultaneous enlargement of both the liver (hepatomegaly) and the spleen (splenomegaly). ... For the bird, see Liver bird. ... The spleen is an organ located in the abdomen, where it functions in the destruction of old red blood cells and holding a reservoir of blood. ... A diagram showing the CNS: 1. ... The human brain In animals, the brain (enkephalos) (Greek for in the skull), is the control center of the central nervous system, responsible for behavior. ... The Spinal cord nested in the vertebral column. ... Myelitis is a human disease involving swelling of the spinal cord, which disrupts central nervous system functions linking brain and limbs. ... Paraplegia is an impairment in motor and/or sensory function of the lower extremities. ... Fibrosis is the formation or development of excess fibrous connective tissue in an organ or tissue as a reparative or reactive process, as opposed to a formation of fibrous tissue as a normal constituent of an organ or tissue. ...

• Colonic polyposis with bloody diarrhea (Schistosoma mansoni mostly);
• Portal hypertension with hematemesis and splenomegaly (S. mansoni, S. japonicum);
• Cystitis and ureteritis (S. haematobium) with hematuria, which can progress to bladder cancer;
• Pulmonary hypertension (S. mansoni, S. japonicum, more rarely S. haematobium);
• Glomerulonephritis; and central nervous system lesions.

Familial adenomatous polyposis (FAP) is an inherited condition in which numerous polyps to form in the epithelium of the large intestine. ... In medicine, portal hypertension is hypertension (high blood pressure) in the portal vein and its branches. ... Hematemesis or haematemesis is the vomiting of fresh red blood. ... Splenomegaly is an enlargement of the spleen, which usually lies in the left upper quadrant (LUQ) of the human abdomen. ... In medicine, hematuria (or haematuria) is the presence of blood in the urine. ... Bladder cancer refers to any of several types of malignant growths of the urinary bladder. ... In medicine, pulmonary hypertension (PH) is an increase in blood pressure in the pulmonary artery, pulmonary vein, or pulmonary capillaries, together known as the lung vasculature, leading to shortness of breath, dizziness, fainting, and other symptoms, all of which are exacerbated by exertion. ... Glomerulonephritis, also known as glomerular nephritis and abbreviated GN, is a primary or secondary immune-mediated renal disease characterized by inflammation of the glomeruli, or small blood vessels in the kidneys. ...

Laboratory diagnosis

Microscopic identification of eggs in stool or urine is the most practical method for diagnosis. The stool exam is the more common of the two. For the measurement of eggs in the feces of presenting patients the scientific unit used is epg or eggs per gram. Stool examination should be performed when infection with S. mansoni or S. japonicum is suspected, and urine examination should be performed if S. haematobium is suspected. Horse feces Feces, faeces, or fæces (see spelling differences) is a waste product from an animals digestive tract expelled through the anus (or cloaca) during defecation. ... This article is about the urine of animals generally. ... An electronic program (or programme) guide, or EPG, is a program schedule, typically broadcast alongside digital television or radio signals. ... Eggs per gram (EPG) is a laboratory test that determines the number of eggs per gram of feces in patients suspected of having a parasitological infection, such as schistosomiasis. ...

Eggs can be present in the stool in infections with all Schistosoma species. The examination can be performed on a simple smear (1 to 2 mg of fecal material). Since eggs may be passed intermittently or in small amounts, their detection will be enhanced by repeated examinations and/or concentration procedures (such as the formalin-ethyl acetate technique). In addition, for field surveys and investigational purposes, the egg output can be quantified by using the Kato-Katz technique (20 to 50 mg of fecal material) or the Ritchie technique.

Eggs can be found in the urine in infections with (recommended time for collection: between noon and 3 PM) S. japonicum' and with S. intercalatum. Detection will be enhanced by centrifugation and examination of the sediment. Quantification is possible by using filtration through a nucleopore membrane of a standard volume of urine followed by egg counts on the membrane. Investigation of S. haematobium should also include a pelvic x-ray as bladder wall calcificaition is highly characteristic of chronic infection. Centrifugation is a process that involves the use of the centrifugal force for the separation of mixtures. ... A nucleopore filter is a kind of filter in which holes a few micrometres in size have been created in a plastic (e. ...

Recently a field evaluation of a novel handheld microscope was undertaken in Uganda for the diagnosis of intestinal schistosomiasis by a team led by Dr. Russell Stothard who heads the Schistosomiasis Control Iniative at the Natural History Museum, London. His report abstract may be found here: [1]

Photomicrography of bladder in S. hematobium infection, showing clusters of the parasite eggs with intense eosinophilia, Source: CDC

Tissue biopsy (rectal biopsy for all species and biopsy of the bladder for S. haematobium) may demonstrate eggs when stool or urine examinations are negative. Histopathology of the bladder showing clusters of Schistosoma hematobium surrounded by inflammed tissue and eosinophilia. ... Histopathology of the bladder showing clusters of Schistosoma hematobium surrounded by inflammed tissue and eosinophilia. ... Brain biopsy A biopsy (in Greek: bios = life and opsy = look/appearance) is a medical test involving the removal of cells or tissues for examination. ...

The eggs of S. haematobium are ellipsoidal with a terminal spine, S. mansoni eggs are also ellipsoidal but with a lateral spine, S. japonicum eggs are spheroidal with a small knob.

Antibody detection can be useful in both clinical management and for epidemiologic surveys. Each antibody binds to a specific antigen; an interaction similar to a lock and key. ... Epidemiology (Greek epi = upon, among; demos = people, district; logos = word, discourse), defined literally, is the study of epidemics in humans. ...

Treatment

Schistosomiasis is readily treated using a single oral dose of the drug Praziquantel. While Praziquantel is safe and highly effective in curing an infected patient, it does not prevent re-infection by cercariae and is thus not an optimum treatment for people living in endemic areas. As with other major parasitic diseases, there is ongoing and extensive research into developing a vaccine that will prevent the parasite from completing its life cycle in humans. Praziquantel (Biltricide) is an anthelmintic effective against flatworms. ...

Antimony has been used in the past to treat the disease. In low doses, this toxic metalloid bonds to sulfur atoms in enzymes used by the parasite and kills it without harming the host. This treatment is not referred to in present-day peer-review scholarship; Praziquantel is universally used. Outside of the US, there is a second drug available for treating Schistosoma mansoni (exclusively) called Oxamniquine. This article is about the element. ... Toxic redirects here, but this is also the name of a song by Britney Spears; see Toxic (song) Look up toxic and toxicity in Wiktionary, the free dictionary. ... This article is about the chemical element. ... Neuraminidase ribbon diagram An enzyme (in Greek en = in and zyme = blend) is a protein, or protein complex, that catalyzes a chemical reaction and also controls the 3D orientation of the catalyzed substrates. ... For other uses, see Peer review (disambiguation). ... Praziquantel (Biltricide) is an anthelmintic effective against flatworms. ... Oxamniquine is an anthelmintic with schistosomicidal activity against Schistosoma mansoni, but not against other Schistosoma spp. ...

Mirazid, a new Egyptian drug, is under investigation for oral treatment of the disease.

Experiments have shown medicinal Castor oil as an oral anti-penetration agent to prevent Schistosomiasis and that praziquantel's effectiveness depended upon the vehicle used to administer the drug (e.g., Cremophor / Castor oil).^[1] Castor oil is a vegetable oil obtained from the castor bean (technically castor seed as the castor plant, Ricinus communis, is not a member of the bean family). ...

Additionally Dr Chidzere of Zimbabwe researched the Gopo Berry (Phytolacca dodecandra) during the 1980's and found that the Gopo Berry could be used in the control of the freshwater snails which carry the bilharzia disease (Schistosomiasis parasite). Dr Chidzere in his interview to Andrew Blake (1989) reported concerns of muti-national chemical companies keen to rubbish the Gopu Berry alternative for snail control ^[2]. Reputedly Gopo Berries from hotter Ethiopia climates yield the best results. Later studies were between 1993-95 by the Danish Research Network for international health. ^[3] Binomial name Sessé & Moc. ...

Prevention through good design

The main focus of prevention is eliminating the water-borne snails which are natural reservoirs for the disease. This is usually done by identifying bodies of water, such as lakes, ponds, etc., which are infested, forbidding or warning against swimming and adding niclosamide, acrolein, copper sulfate, etc., to the water in order to kill the snails. Natural reservoir or nidus, refers to the long-term host of the pathogen of an infectious disease. ... In organic chemistry, acrolein or propenal is the simplest unsaturated aldehyde. ... Copper (II) sulfate (CuSO4) is the most common copper salt, made by the action of sulfuric acid on the base copper oxide. ...

Unfortunately for many years from the 1950s onwards, despite the efforts of some clinicians to get civil engineers to take it into account in their designs, civil engineeers built vast dam and irrigation schemes, oblivious of the fact that they would cause a massive rise in water-borne infections from schistosomiasis, even though with a little care the schemes could have been designed to minimise such effects, the detailed specifications having been laid out in various UN documents since the 1950s. Irrigation schemes can be designed to make it hard for the snails to colonise the water, and to reduce the contact with the local population. ^[4]

Failure for engineers to take this into account is an interesting example of the Relevance Paradox and is a good example of the failure of formal education and information systems to transmit tacit knowledge. The Relevance Paradox occurs where individual, professionals or groups of professionals are unaware of certain essential information which would guide them to better decisions, and help avoid inevitable, unintended and undesirable consequences, but lacking the information, they dont see its relevance so dont seek it. ... The concept of tacit knowing comes from scientist and philosopher Michael Polanyi. ...

Prevention and hygiene

This article may require cleanup to meet Wikipedia's quality standards. Please improve this article if you can. (August 2006)

Prevention is best accomplished by eliminating the water-dwelling snails which are the natural reservoir of the disease. Acrolein, copper sulfate, and niclosamide can be used for this purpose. Recent studies have suggested that snail populations can be controlled by the introduction or augmentation of existing crayfish populations; as with all ecological interventions, however, this technique must be approached with caution. Image File history File links Broom_icon. ... Natural reservoir or nidus, refers to the long-term host of the pathogen of an infectious disease. ... In organic chemistry, acrolein or propenal is the simplest unsaturated aldehyde. ... Copper (II) sulfate (CuSO4) is the most common copper salt, made by the action of sulfuric acid on the base copper oxide. ...

Individuals can guard against schistosomiasis infection by avoiding bodies of water known or likely to harbor the carrier snails.

In 1989, Aklilu Lemma and Legesse Wolde-Yohannes received the Right Livelihood Award for their research on the sapindus-Plant (Phytolacca dodecandra), as a preventative measure for the disease by controlling the snail. Jakob von Uexkull, founder of the Right Livelihood Award The Right Livelihood Award, established in 1980 by Jakob von Uexkull, is presented annually in the building of the Swedish Parliament, usually on December 9, to honour those working on practical and exemplary solutions to the most urgent challenges facing the... Species See text Sapindus is a genus of about five to twelve species of shrubs and small trees in the Sapindaceae, native to warm temperate to tropical regions in both the Eastern and Western Hemispheres. ...

See also

Wikimedia Commons has media related to:

Schistosoma

• Tropical disease

Image File history File links Commons-logo. ... Tropical diseases are infectious diseases that either occur uniquely in tropical and subtropical regions (which is rare) or, more commonly, are either more widespread in the tropics or more difficult to prevent or control. ...

References

1. ^ Schistosoma mansoni: experimental chemoprophylaxis in mice using oral anti-penetration agents.. pubmed. Retrieved on 2007-01-25.
2. ^ The Gopu Berry p33. Part 4 School Journal number.2 1989 Dept of Education Wellington N.Z
3. ^ http://enrecahealth.ku.dk/postgrad_dbl_en/chihaka_abs/
4. ^ Charnock, Anne (1980) Taking Bilharziasis out of the irrigation equation. New Civil Engineer, 7 August. 1980 Bilharzia caused by poor civil engineering design due to ignorance of cause and prevention

• Center for Disease Control, Schistosomiasis. (2004)

Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 25th day of the year in the Gregorian calendar. ... The Centers for Disease Control and Prevention (CDC) in Atlanta is recognized as the lead United States agency for protecting the public health and safety of people by providing credible information to enhance health decisions, and promoting health through strong partnerships with state health departments and other organizations. ... Year 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ...

External links

• World Health Organization Partners for Parasite Control website
• World Health Organization fact sheet on the disease
• Wellcome animation of the life cycle of the parasite
• Schistosomiasis Control Initiative
• CONTRAST, a research project on optimized schistosomiasis control in Sub-saharan Africa
• World Health Organization Tropical Disease Research programme
• Cambridge University Schistosomiasis Research Group
• York University Schistosomiasis Research Group
• Schistosomiasis (Bilharzia) Control and Prevention: The Carter Center Schistosomiasis Control Program
• Links to Schistosomiasis pictures (Hardin MD/Univ of Iowa)
• FIOCRUZ - Schistomiasis Research Group
• Sandler Center for Basic Research in Parasitic Diseases, University of California San Francisco
• Vacine developed in Queensland, Australia
• DBL - Centre for Health Research and Development
• 10. Charnock, Anne (1980) Taking Bilharziasis out of the irrigation equation. New Civil Engineer, 7 August. Bilharzia caused by poor civil engineering design due to ignorance of cause and prevention.