Spread of Pathogens Is Highly Evolved

As long as a resistant infection is limited to its initial patient, disease can be controlled by isolating the patient. But when isolation is not achieved and the pathogen spreads, resistance also spreads. Resulting infections generally fail to respond to the antibiotic, and an outbreak of drug-resistant disease can occur. Indeed, outbreaks are what usually come to mind when we hear the term antibiotic resistance in reference to situations in hospitals.

Transmission of resistant pathogens follows the same paths as transmission of susceptible pathogens: through the air, in food and water, by direct contact with infected persons, and via insect vectors. Consequently, controlling resistant outbreaks employs the same infection-control practices normally associated with disease. But the sense of urgency is much greater, because the usual antibiotic-based cures won’t work—we must switch to other agents, if they are available.