Final answer:
Blood flukes, causing schistosomiasis, are common in tropical and subtropical regions and involve freshwater snails in their life cycle. Humans get infected when they come into contact with water where the larvae reside. A significant global population requires treatment for schistosomiasis.
Step-by-step explanation:
Common Habitats of Blood Flukes
Blood flukes, also known as schistosomes, are a type of parasitic flatworm. These organisms are particularly common in tropical and subtropical regions such as the Caribbean, South America, the Middle East, Asia, and Africa. Schistosomiasis, also known as bilharzia, is a disease caused by blood flukes and is second only to malaria in terms of its impact on human populations.
The parasites responsible for this disease, mainly Schistosoma mansoni, S. haematobium, and S. japonicum, have a complex life cycle that includes freshwater snails as an intermediary host before they infect humans. Infection often occurs when humans come into contact with contaminated water and the fluke larvae penetrate the skin. These flukes then migrate through the human body to organs such as the liver and intestines, where they mature into adults and cause various symptoms.
The World Health Organization (WHO) estimates that a significant number of people globally require preventive treatment for schistosomiasis. Proper diagnosis of the disease is crucial and involves examining feces or other samples through immunoassay to detect the presence of flukes.