Before 1940, most waterborne disease fatalities were attributed to which illness?

Before 1940, typhoid fever was the leading cause of waterborne disease fatalities. This disease is caused by the bacterium Salmonella enterica serotype Typhi, which is primarily transmitted through contaminated water and food. In the early 20th century, inadequate sanitation practices and poor water treatment led to widespread outbreaks, making typhoid fever a significant public health concern.

The mortality rate associated with typhoid fever was particularly high before the development of effective treatments and vaccines. Additionally, typhoid fever often resulted in severe complications, contributing to its role as a major cause of death related to waterborne illnesses during that time period. Efforts to improve water quality and sanitation practices in the years following helped reduce the incidence of typhoid fever significantly.

While cholera and dysentery were also important waterborne diseases, and they did contribute to fatalities, the impact of typhoid fever was particularly pronounced in many urban areas due to the interconnectedness of water supply and waste disposal systems. Hepatitis A, although transmissible through contaminated water, typically did not lead to the same high fatality rates as typhoid fever, especially before advances in public health interventions.