The moment of wound colonization is always known. By review of the anesthesia record, it is obvious when the incision was made and when the incision was closed. Should external violence have accounted for the wound, then history or reference to emergency room records will give the specific time of inoculation. Only rarely does a soft tissue infection arise as a result of hematogenous spread. The interval of time between when the wound was contaminated and when the patient presents or at least experiences first signs or symptoms is called the incubation period.
Different pathogens have different durations for incubation.
The greater the virulence of the organism, the shorter is the period of time between inoculation and local signs of infection. This then makes it quite easy to incriminate a specific microbe or set of pathogens. Indeed, there are certain scenarios that are peculiarly explicit for a given microbe, causing its characteristic infection. The majority of soft tissue infections are associated with an exudate. Examination of a stained smear is reliable at revealing the responsible organism, provided that the wound was not drained for several days earlier and thus has had the opportunity for secondary colonization.