Final answer:
A century ago, doctors could often diagnose diseases but lacked effective treatments and cures. Advancements in germ theory and technology have since enabled better disease management.
Step-by-step explanation:
As recently as 100 years ago, doctors might have been able to diagnose an illness, but they were often unable to treat it, much less cure it. At that time, medical knowledge and technology were not as advanced as they are today, which significantly limited the options for treatment and prevention of diseases. Historically, some diseases were understood to be contagious, and measures like quarantine were used to try and control their spread, even before the mechanisms of contagion were well-understood. However, it was not until the discovery of germ theory and advancements in biotechnology that significant progress was made in the prevention, treatment, and cure of infectious diseases.