Schistosomiasis is known as bilharzia or bilharziosis in many countries, after Theodor Bilharz, who first described the cause of urinary schistosomiasis in 1851. It is a parasitic disease.
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.
Today it can be cured with a single oral dose of the drug praziquantel annually
Among human parasitic diseases, schistosomiasis ranks second behind malaria in terms of socio-economic and public health importance in tropical and subtropical areas. The disease is endemic in 74-76 developing countries, infecting more than 207 million people, 85% of whom live in Africa. They live in rural agricultural and peri-urban areas, and placing more than 700 million people at risk.
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.
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.
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. 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.
Schistosomiasis is readily treated using a single oral dose of the drug praziquantel annually. As with other major parasitic diseases, there is ongoing and extensive research into developing a schistosomiasis vaccine that will prevent the parasite from completing its life cycle in humans. In 2009, Eurogentec Biologics developed a vaccine against bilharziosis in partnership with INSERM and researchers from the Pasteur Institute.
The World Health Organization has developed guidelines for community treatment of schistosomiasis based on the impact the disease has on children in endemic villages:[13]
When a village reports more than 50 percent of children have blood in their urine, everyone in the village receives treatment.
When 20 to 50 percent of children have bloody urine, only school-age children are treated.[13]
When less than 20 percent of children have symptoms, mass treatment is not implemented.[13]
The Bill & Melinda Gates Foundation has recently funded an operational research program---the Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) to answer strategic questions about how to move forward with schistosomiasis control and elimination. The focus of SCORE is on development of tools and evaluation of strategies for use in mass drug administration campaigns.
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 U.S., there is a drug available exclusively for treating Schistosoma mansoni (oxamniquine) and one exclusively for treating S.hematobium (metrifonate). While metrifonate has been discontinued for use by the British National Health Service, a Cochrane review found it equally effective in treating urinary schistosomiasis as the leading drug, praziquantel.
Mirazid, an Egyptian drug made from myrrh, was under investigation for oral treatment of the disease up until 2005. The efficacy of praziquantel was proven to be about 8 times than that of Mirazid and therefore Mirazid was not recommended as a suitable agent to control schistosomiasis.
Not to be confused with:
Leishmaniasis
The treatment of leishmania with antimony potassium tartrate started in 1913. Leishmaniasis is a disease caused by protozoan parasites that belong to the genus Leishmania and is transmitted by the bite of certain species of sand fly (subfamily Phlebotominae). Although the majority of the literature mentions only one genus transmitting Leishmania to humans (Lutzomyia) in America, a 2003 study by Galati suggested a new classification for American sand flies, elevating several subgenera to the genus level. Elsewhere in the world, the genus Phlebotomus is considered the vector of leishmaniasis.
Most forms of the disease are transmissible only from animals (zoonosis), but some can be spread between humans. Human infection is caused by about 21 of 30 species that infect mammals.
Leishmaniasis can be transmitted in many tropical and subtropical countries, and is found in parts of about 88 countries. Approximately 350 million people live in these areas. The settings in which leishmaniasis is found range from rainforests in Central and South America to deserts in West Asia and the Middle East. It affects as many as 12 million people worldwide, with 1.5–2 million new cases each year.
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