The 1968 song "Good Lovin" performed by The Young Rascals is about a doctor:

I was feeling, so bad
I asked my family doctor just what I had
I said Dr. (Dr.)
Mr. M.D. (Dr.)
Now can you tell me what's ailing me (Dr.)
He said yeah,yeah,yeah,yeah,yeah

Ok. It won't win a Grammy or go Platinum but it is great to dance to, as Dick Clark used to say on American Band Stand. It's a real fun song and might easily fit into a high school stage production. A lot of different groups have performed it, including The Shondells and The Who.

Eminem and Dr. Dre, "I Need A Doctor"--  Eminem really wants a doctor to bring him back to life.  Could Dr. Dre be the one?  Has back up vocals by Skylar Grey.

And don't forget the Medieval Classic "Ring Around the Roses"-- This charming children's song is about the black plague.  The ring around the roses actually represents the red blisters and spots accompanying the symptoms of the plague.  "Ashes, Ashes, We all fall down"--Yes, you guessed it!  Everybody dies.  And our children are still singing this song today.  I bet it's the most popular virus song ever!  It has definitely stood the test of time.

Bruce Springsteen's "Streets of Philadelphia" is about a man confronting AIDS, and if I remember correctly, TLC's classic "Waterfall" is also partially about AIDS or another STD. "Brick" by Ben Folds Five is about a teenage girl that receives an abortion.

Robert Palmer: Bad Case of Loving You (Doctor Doctor Give Me the News)

Johnny Rivers: Rockin Pneumonia

Kiss: Doctor Love

And, just in case you wanted to find a real oldie:

David Seville: Witch Doctor

There have been songs written about things such as diseases, bacterias, and other medical terminology (doctors, nurses, etc.). While some are metaphorical, others are very straight-forward and blatant about the topic. Here are a few examples.

The Dead Kennedys- "Government Flu"

Motley Crue- "Doctor Feelgood"

Ben Lee- "Catch My Disease"

My Chemical Romance- "Blood"

Linkin Park- "Bleed It Out"

Unknown- "Bacteria"