01 / The world before
Infections spread without a clear account of their causes.
02 / The discovery
Microbiology connected microorganisms with disease, leading to new prevention strategies.
03 / The people
Pasteur, Koch and many laboratory and public-health workers.
04 / The obstacles
Understanding a mechanism did not itself create clean facilities or access to care.
05 / The world after
Hospitals and communities could design more effective infection control.
06 / Why it still matters
Hand hygiene, safe water and laboratory testing still depend on this insight.