Lab and culture reports

This page explains how we use culture reports to confirm infections and pathogens.

Additional Information

• This is about identification of a clinical infection.
  • For disorders believed to be infectious, we have a list of pathogens, and if the pathogen is never identified then you can use Infectious organism, unknown.
• Even if you do identify one or more organisms that are potential pathogens, usually it requires clinical correlation to decide whether it/they are actually pathogenic in this patient
  • There are very few bugs that are always pathogenic (i.e. causing an infectious disease) -- high on this list is M.Tb. and Legionella. Even organisms like Aspergillis can be colonizers.
  • Thus identifying whether a potential pathogen is in fact acting as a pathogen in a given patient requires clinical correlation.
• Having said that:
  • While it is strongest to have a lab sample (fluid or tissue) from which the organism has been cultured, there are circumstances where this isn't necessary, e.g. Infection with implied pathogen
  • Even a lab identification may not be from culturing -- e.g. there are monoclonal antibody and other non-culture methods such as antigen identification (e.g. Legionella urinary antigen) that can identify the presence of a bug
• The question arises of whether when you do NOT have any sort of lab identification of a bug, whether clinical suspicion is enough to "call it":
  • Again, the answer is generally "Yes" with Infection with implied pathogen, and generally "No" elsewise -- deviating from these generalities can be done if you've got an excellent, scientific rationale.

How and when infections are identified is relevant to Attribution of infections.