crab louse vs gonorrhea

crab louse

noun
  • A parasitic insect, Pthirus pubis, that lives amongst the pubic hairs of humans and feeds on blood. 

gonorrhea

noun
  • A sexually transmitted infection caused by Neisseria gonorrhoeae, a species of bacteria (the gonococcus) that affects the mucous membrane of the genital and urinary tracts. 

How often have the words crab louse and gonorrhea occurred in a corpus of books? (source: Google Ngram Viewer )