Which is the first link in the cycle of infection?

Which is the first link in the cycle of infection?

• A. Reservoir host
• B. Means of exit
• C. Means of transmission
• D. Means of entrance

Answer: (A)

The first link is the reservoir, which is the place where the infectious agent normally lives and multiplies. This reservoir provides the source from which the pathogen can exit and be transmitted to a new host. Without a reservoir, there is nothing to start the cycle. After the reservoir, the cycle proceeds through exit, transmission, entry, and then a susceptible host. The other options represent steps that occur after the pathogen leaves its source, not the starting point.

The first link is the reservoir, which is the place where the infectious agent normally lives and multiplies. This reservoir provides the source from which the pathogen can exit and be transmitted to a new host. Without a reservoir, there is nothing to start the cycle. After the reservoir, the cycle proceeds through exit, transmission, entry, and then a susceptible host. The other options represent steps that occur after the pathogen leaves its source, not the starting point.