affect vs infect

affect

verb
  • To move to emotion. 

  • To make a show of; to put on a pretense of; to feign; to assume. To make a false display of. 

  • To feel affection for (someone); to like, be fond of. 

  • To burden (property) with a fixed charge or payment, or other condition or restriction. 

  • To influence or alter. 

  • Of an illness or condition, to infect or harm (a part of the body). 

noun
  • A subjective feeling experienced in response to a thought or other stimulus; mood, emotion, especially as demonstrated in external physical signs. 

infect

verb
  • To make somebody enthusiastic about one's own passion, or to communicate a feeling to others, or a feeling communicating itself to others. 

  • To bring (the body or part of it) into contact with a substance that causes illness (a pathogen), so that the pathogen begins to act on the body; (of a pathogen) to come into contact with (a body or body part) and begin to act on it. 

  • To contaminate (an object or substance) with a pathogen. 

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