That it is at least as difficult to staya moral infection as a physical one; that such a disease will spread with the malignityand rapidity of the Plague; that the contagion, when it has once made head, will spare no pursuit or condition, but will lay hold on people in the soundest health, and become developed inthe most unlikely constitutions; is a fact as firmlyestablished by experience as that we human creatures breathe an atmosphere.

-Dickens, CharlesJohn Huffam
^7  Little Dorrit, bk.2, ch.13.

Sure there's contagion in the tears of friends.

-Dryden,John
  All for Love, or The World Well Lost, act1.

The sad presaging raven, that tolls The sick man's passport in her hollow beak, And in the shadow of the silent night Doth shake contagion from her sable wings.

-Marlowe, Christopher
c.1589  The Jew of Malta (published1633), act 2, sc.1.

Theyare sped; And when they list, their lean and flashy songs 578 Grate on their scrannel Pipes of wretched straw, The hungry sheep look up, and are not fed, But swollen with wind, and the rank mist they draw, Rot inwardly, and foul contagion spread, Besides what the grim wolf with privy paw Daily devours apace, and nothing said, But that two-handed engine at the door, Stands ready to smite once, and smite no more.

-Milton,John
  Lycidas, l.122^31.

   He has out-soared the shadow of our night; Envyand calumnyand hate and pain, And that unrest which men miscall delight, Can touch him not and torture not again; From the contagion of the world's slow stain He is secure, and now can never mourn A heart grown cold, a head grown grey in vain.

-Shelley, Percy Bysshe
Adonais, stanza 40.

   To be, or not to be; that is the bare bodkin That makes calamity of so long life; For who would fardels bear, till Birnam Wood do come to Dunsinane, But that the fear of something after death Murders the innocent sleep, Great nature's second course, And makes us rather sling the arrows of outrageous fortune Than fly to others that we know not of. There's the respect must give us pause: Wake Duncan with thy knocking! I would thou couldst; For who would bear the whips and scorns of time,

-Twain, Mark pseudonym of  Samuel Langhorne Clemens

Ninety-ninepercent of the people inthe world are fools, and the rest of us are in great danger of contagion.

-Wilder,Thornton Niven
  The Matchmaker, act1.