John Snow's cholera work laid the foundation for which two branches of microbiology?

• A. Infection control and epidemiology
• B. Immunology and virology
• C. Bacteriology and mycology
• D. Pharmacology and toxicology

Answer: (A)

John Snow’s cholera work demonstrates how disease transmission in a population can be understood and interrupted, which is the essence of epidemiology and infection control. By meticulously collecting data on cholera cases, mapping where they occurred, and tracing them to a common water source, he showed that how people are exposed drives outbreaks. His recommendation to remove the Broad Street pump handle put a practical control measure into action, stopping further transmission and illustrating infection-control thinking—changing environments to reduce exposure. This combination—studying disease patterns at the population level and applying interventions to prevent spread—laid the foundation for epidemiology as a discipline and for infection-control practices in public health and medicine.