Rich King T. Valdez
Juan Carlo Pangan
Schistomiasis is a disease that is caused by parasites (genus Schistosoma) that enter humans by attaching to the skin, penetrating it, and then migrating through the venous system to the portal veins where the parasites produce eggs and eventually, the symptoms of acute or chronic disease.
Schistosomiasis has been affecting human health for at least 4,000 years; characteristic symptoms are described in early Egyptian papyri and analysis reveals immunological cues as to its presence in ancient mummies.
-1851 the German physician Theodor Bilharz. Working out of Cairo, Egypt he first identified adult male and female Schistosoma haematobium.
- 1904 S. japonicum is discovered in Hiroshima Japan and named the disease Katayama fever
-1907 S. mansoni was described and named in the honor of Sir Patrick Manson, the first scientist to speculate that the difference in egg morphology and manner
SCHISTOSOMA species display a unique feature amongst the Trematoda because they are dioecious and form pairs in their definitive hosts
The Adult male – up to 10 mm in length, possesses a body groove called gynaecorphoral canal and has 6 to 9 testes
The female – up to 10 – 14 mm in length nad has a single ovary located in the anterior portion of the body
Female Schistosoma = deposit 190 to 300 eggs daily,
Among 18 Species of Schistosoma, there are 3 main species of it that infect human
1). Under optimal conditions the eggs hatch and release miracidia
2),which swim and penetrate specific snail intermediate hosts
3). The stages in the snail include 2 generations of sporocysts
4) production of cercariae
5). Upon release from the snail, the infective cercariae swim, penetrate the skin of the human host
6), and shed their forked tail, becoming schistosomulae
7). The schistosomulae migrate through several...