Infectious Diseases: Diagnosticians of the Weird

DISEASES by ~scythemantis on deviantART

Infectious diseases (henceforth called "ID") is one of three hospital services that is consulted when nothing else makes sense, the other two being rheumatology and immunology.  I was specifically on the pediatric ID service and, time and time again, I've seen these three services consulted on a patient when the primary care team scratches their heads and throws up their hands in frustration.

I came into medical school with a strong interest in ID, having just completed a year (out of two) of a Master's in Public Health in a Hospital & Molecular Epidemiology sub-program focusing on microbiology and disease transmission.  It's a fascinating field with strong ties to public and global health.  I think what attracts me most to ID is that you still have to know a little about everything.  Infections don't just affect one organ or a couple organs, it can involve any part of the body and so you really need to know enough about everything that's going on.  The ID attendings I've worked with are some of the most brilliant (even terrifyingly so) physicians I've ever met.

ID is mainly an inpatient consult service, and is thus consulted by the primary care team to help diagnose and treat things that may have an infectious etiology.  There are several things to know about how the ID team thinks:

Trends: ID is all about trends - trends in fever, inflammatory markers (CRP, ESR, etc), cultures, wound healing, etc.  Trends allow an ID team to see if the patient is suddenly doing worse or conversely responding to treatment.  Trends can also clue in an ID team as to whether the patient has something infectious or not in the first place.

Causality: By its very nature, ID seeks to determine a discrete cause for a disease.  They will question the patient/family for any and all exposures to find some clue in the history for why they're even being consulted.  They will go to some length to obtain cultures from blood, cerebrospinal fluid (CSF), sputum, pus, biopsies, etc to determine what organism(s) grow out of it which may be causing disease.

Proper Coverage: ID is fastidious about the drugs it employs for treatment.  The fear and bane of ID is when a bug becomes resistant to treatment (e.g. MRSA and certain antibiotics).  They are infuriated when other services immediately go for the "big guns" - the stronger medications known to treat a microbe - because overuse breeds resistance.  They are also annoyed when other services switch antibiotics too quickly because they don't see an immediate effect or "double cover" the same organism.

A Motley Crew: The ID team can be a mix of people you may not initially expect.  Of course there is the ID physician, but in addition there may be an ID pharmacist who helps dose and regulate the use of antibiotics throughout the hospital as well as microbiology pathologists who look at the cultures for the ID team (and who answer more readily to the ID service than the rest of the hospital).

Know Your Consult: When you consult the ID team (or any consult service for that matter), make sure you have a good intelligent question and reason for consult.  It should never be, "We don't know what this is, the kid is having a fever, please figure it out for us!" or "We think it's this, are we using the right drug?"  Rather you need to make a convincing case why the ID team needs to be involved - also, this is partly why the ID team usually only sees the most severe and/or bizarre cases, haha.

Read more...