Which of the following diseases caused by waterborne pathogens is associated with a high mortality rate?

Typhoid fever, caused by the bacterium Salmonella Typhi, is associated with a particularly high mortality rate among waterborne diseases. This illness can manifest with severe complications if left untreated, including intestinal hemorrhage and perforation, which can lead to septicemia. Typhoid is primarily transmitted through contaminated water and food, highlighting the importance of clean water sources and effective sanitation practices in preventing this disease.

While Giardia, hepatitis, and dysentery can also cause illness linked to waterborne pathogens, their associated mortality rates are generally lower compared to typhoid fever. Giardia causes giardiasis, which may lead to gastrointestinal discomfort but is rarely fatal, especially with appropriate treatment. Hepatitis, particularly hepatitis A, is transmitted via contaminated water but does not typically result in high mortality; the prognosis is generally favorable. Dysentery, primarily caused by Shigella or Entamoeba histolytica, can be severe and lead to dehydration but usually has a lower mortality rate in comparison to typhoid fever, particularly in populations with access to medical care. This distinction in the associated severity and outcomes of these diseases highlights why typhoid fever stands out in terms of its high mortality risk.