Hansen's disease vs glanders

Hansen's disease

noun
  • The disease leprosy, caused by infection by Mycobacterium leprae. 

glanders

noun
  • An infectious disease of horses, mules and donkeys caused by the bacterium Burkholderia, one species of which may be transmitted to humans. 

How often have the words Hansen's disease and glanders occurred in a corpus of books? (source: Google Ngram Viewer )