herpes zoster vs shingles

herpes zoster

noun
  • An acute viral inflammation of the sensory ganglia of spinal and cranial nerves associated with a vesicular eruption and neuralgic pains, caused by reactivation of the Human herpes virus 3, in genus Varicellovirus, that also causes chicken pox as primo-infection. 

shingles

noun
  • Herpes zoster, caused by Human herpes virus 3, in genus Varicellovirus. 

How often have the words herpes zoster and shingles occurred in a corpus of books? (source: Google Ngram Viewer )