chancroid vs chlamydiosis

chancroid

noun
  • A sexually transmitted infection, caused by bacteria of species Haemophilus ducreyi, characterized by painful sores on the genitalia. 

  • A sore characteristic of this infection. 

chlamydiosis

noun
  • infection by bacteria of the genus Chlamydia 

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