1. The characteristic of a disease agent that embodies capability of entering, surviving in, and multiplying and causing disease in a susceptible host. 2. The proportion of exposures in defined circumstances that result in infection.
* * *
in·fec·tiv·i·ty .in-.fek-'tiv-ət-ē n, pl -ties the quality of being infective: the ability to produce infection specif a tendency to spread rapidly from host to host compare VIRULENCE (b)
* * *
in·fec·tiv·i·ty (in″fek-tivґĭ-te) 1. the state or quality of being infectious; called also infectiousness. 2. virulence.Medical dictionary. 2011.