What is a significant risk factor for acquiring schistosomiasis?

Contact with fresh water is a significant risk factor for acquiring schistosomiasis due to the lifecycle of the infecting parasites, known as Schistosoma species. The larvae of these parasites, called cercariae, are found in freshwater bodies such as lakes, rivers, and ponds. When a person comes into contact with contaminated water, especially through activities such as swimming, bathing, or washing clothes, cercariae can penetrate the skin and enter the bloodstream, leading to infection.

While improper sanitation can contribute to the spread of parasites through contaminated water sources, it is the direct contact with fresh water that poses the immediate risk for transmission. Ingestion of undercooked fish is associated with other parasitic infections, such as certain trematodes and cestodes, but not schistosomiasis. Although travel to tropical regions can increase exposure to various diseases, the specific risk of schistosomiasis primarily arises from direct interaction with fresh water that may harbor the parasite's larvae. Thus, direct contact with fresh water is the critical factor to consider.