<prompt> nosocamial infection after how many hours ?48hrs72hrs7 days1 day  <response>: Any infection causing illness that was not present or in its incubation period when the subject entered hospital or received treatment in outpatient clinic. Infections are considered Nosocomial if they first appear 48 hours or more after hospital admission or within 30 days after discharge. Nosocomial comes from two Greek words- nosus meaning diseasekomeion meaning to take care of---disease contracted by a patient while under medical care. ref : harrisons 21st ed 