Final answer:
Schistosomiasis, or bilharzia, is a helminthic infestation caused by schistosome flatworms. It affects humans when they come into contact with contaminated freshwater. The parasites can cause significant organ damage and have severe long-term consequences.
Step-by-step explanation:
Schistosomiasis in Humans
Schistosomiasis, also known as bilharzia, is a type of helminthic infestation. It is caused by parasitic flatworms belonging to the genus Schistosoma. These parasites have a complex life cycle that includes an intermediary host, usually freshwater snails, and a definitive host, which is humans. Infection in humans occurs when they come into contact with freshwater contaminated with the parasite's larvae. The larvae penetrate human skin, usually through a hair follicle, and then enter the bloodstream.
The disease is prevalent in tropical regions where irrigation is widespread and has been a health concern since ancient times. In schistosomiasis, the parasites can lead to significant organ damage, and symptoms may include abdominal pain, bloody stool, and fatigue. Long-term consequences can be severe, including liver damage, kidney failure, infertility, bladder cancer, and in children, impaired growth and learning difficulties.
The key to controlling schistosomiasis lies in improving sanitation, controlling snail populations, and treating infected individuals. Preventive measures also include avoiding contact with contaminated waters, though for many in endemic regions, this is a challenge due to their daily routines and the necessity of utilizing local water sources.