proper part of continuant at all times is about has participant has_participant basic reproduction number basicReproductionNumbers MB: Here we run into the well know DL problem that we cannot specify that the infectious agent that is transmitted is of the same type that the infectious agent the population is susceptible to. The average number of transmissions of an infectious agent from an infectious organism to a susceptible organism within a completely susceptible population. The number of organisms that each infected organism infects in a completely susceptible population during its infectious period. William R. Hogan reproduction number infection acquisition susceptible population organism