Conditions that all must be present for infection to occur are called what?

Conditions that all must be present for infection to occur are called what?

• A. Chain of Infection
• B. Chronic Infection
• C. Direct Contact
• D. Droplet Infection

Answer: (A)

All infections require a chain of factors to be in place. This chain includes the infectious agent, a reservoir where it can live, a way for it to exit that reservoir, a method for it to reach a new person (mode of transmission), a portal of entry into that person, and a susceptible host. If any one link is interrupted—such as by sterilizing equipment, washing hands to block transmission, using barriers to prevent entry, or immunizing people to reduce susceptibility—the chain is broken and infection cannot occur. The other terms describe either how long an infection lasts (chronic) or specific routes of transmission (direct contact, droplet) rather than the complete set of conditions needed for infection.

All infections require a chain of factors to be in place. This chain includes the infectious agent, a reservoir where it can live, a way for it to exit that reservoir, a method for it to reach a new person (mode of transmission), a portal of entry into that person, and a susceptible host. If any one link is interrupted—such as by sterilizing equipment, washing hands to block transmission, using barriers to prevent entry, or immunizing people to reduce susceptibility—the chain is broken and infection cannot occur. The other terms describe either how long an infection lasts (chronic) or specific routes of transmission (direct contact, droplet) rather than the complete set of conditions needed for infection.