Infectious disease specialist
Today, a student asked me if he could use the word "infectiologist". I didn't find it in any dictionary I looked up in. However, it doesn't mean people don't use it. For instance, in this website, we find it in the title:
http://www.romwell.com/cookbook/guide/infectiologist.html

Have you ever heard or read native English speakers say "infectiologist"? Even more important: have you ever heard physicians using this word?
How about you, physicians, what word would you choose to describe this reality? Does "infectiologist" work fine for you?

Thank you!
[I will be glad if you correct my English mistakes ^^]For those who use the word "infectiologist": would you prefer saying "infectious disease specialist" or "infectiologist", when asked what you specialize in?

Question

Infectious disease specialist
Today, a student asked me if he could use the word "infectiologist". I didn't find it in any dictionary I looked up in. However, it doesn't mean people don't use it. For instance, in this website, we find it in the title:
http://www.romwell.com/cookbook/guide/infectiologist.html

Have you ever heard or read native English speakers say "infectiologist"? Even more important: have you ever heard physicians using this word?
How about you, physicians, what word would you choose to describe this reality? Does "infectiologist" work fine for you?

Thank you! 
[I will be glad if you correct my English mistakes ^^]For those who use the word "infectiologist": would you prefer saying "infectious disease specialist" or "infectiologist", when asked what you specialize in?

Answer

I'm a medical student (studying to be a physician) and I have never heard "infectiologist" used. In the United States at least we say "infectious disease specialist." Among physicians there is also the abbreviation "ID," so for example one could say "he's an ID specialist" or "an ID doc." These are too informal for writing, of course. 
I have heard "infectology" when talking about the study of infectious diseases, but even in medical dictionaries there is no such word as "infectologist" or "infectiologist."
I myself wish to be an infectious disease specialist!

Answer

Have I ever heard the word 'infectiologist?' No. 
Would I ever use it myself? No.
'Infectious disease specialist' or (better) 'specialist in infectious disease' sound good, like something a native speaker would say.

Answer

Either way, Infectiologist or infectious disease specialists are both used in hospital environments​.