Schistosomiasis overview: Difference between revisions
| Line 22: | Line 22: | ||
==Natural History, Complications and Prognosis== | ==Natural History, Complications and Prognosis== | ||
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 [[embolism|embolic]] egg granulomas in [[brain]] or [[spinal cord]]. Pathology of ''S. haematobium'' schistosomiasis includes: [[hematuria]], [[scar]]ring, [[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. | 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 [[embolism|embolic]] egg granulomas in [[brain]] or [[spinal cord]]. Pathology of ''S. haematobium'' schistosomiasis includes: [[hematuria]], [[scar]]ring, [[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. | ||
==Diagnosis== | |||
===History and Symptoms=== | |||
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''. | |||
==References== | ==References== | ||
Revision as of 15:20, 5 December 2012
|
Schistosomiasis Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
Case Studies |
|
Schistosomiasis overview On the Web |
|
American Roentgen Ray Society Images of Schistosomiasis overview |
|
Risk calculators and risk factors for Schistosomiasis overview |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Schistosomiasis (also known as bilharzia, bilharziosis or snail fever) is a parasitic disease caused by several species of trematodes (platyhelminth infection, or "flukes"), a parasitic worm of the genus Schistosoma. Snails serve as the intermediary agent between mammalian hosts. Individuals within developing countries who cannot afford proper water and sanitation facilities are often exposed to contaminated water containing the infected snails.[1]
Although it has a low mortality rate, schistosomiasis often is a chronic illness that can damage internal organs and, in children, impair growth and cognitive development. The urinary form of schistosomiasis is associated with increased risks for bladder cancer in adults. Schistosomiasis is the second most socioeconomically devastating parasitic disease after malaria.[2]
This disease is most commonly found in Asia, Africa, and South America, especially in areas where the water contains numerous freshwater snails, which may carry the parasite.
The disease affects many people in developing countries, particularly children who may acquire the disease by swimming or playing in infected water.[2] When children come into contact with a contaminated water source, the parasitic larvae easily enter through their skin and further mature within organ tissues. As of 2009, 74 developing countries statistically identified epidemics of Schistosomiasis within their respective populations.[1]
Historical Perspective
Schistosomiasis is known as bilharzia or bilharziosis in many countries, after German physician Theodor Bilharz, who first described the cause of urinary schistosomiasis in 1851. The first doctor who described the entire disease cycle was Pirajá da Silva in 1908. It was a common cause of death for Ancient Egyptians in the Greco-Roman Period.[3]
Classification
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.
Pathophysiology
Schistosomes have a typical trematode vertebrate-invertebrate lifecycle, with humans being the definitive host.
Epidemiology and Demographics
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.
Natural History, Complications and Prognosis
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.
Diagnosis
History and Symptoms
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.
References
- ↑ 1.0 1.1 "CIA - The World Factbook." Central Intelligence Agency, 4 Apr. 2007 "cia.gov".
- ↑ 2.0 2.1 The Carter Center. "Schistosomiasis Control Program". Retrieved 2008-07-17.
- ↑ "Proceedings of the 13h Annual History of Medicine Days", a medical historical paper from University of Calgary. March 2004.