Action Comics Vol 1 #363

In prison, Lex Luthor gains access to the biochem lab, and developes Virus X, a plague germ that has been irradiated with Kryptonite. It kills Earth beings in minutes, and is even capable of killing Superman.

Lex secretly passes a vial of Virus X to the criminal ventriloquist Ventor who had captured and hypnotized Clark Kent.^[1] Ventor returns to his hideout and orders Kent to infect Superman. The mesmerized Clark doesn't remember that he is Superman, but does remember enough to climb into his apartment and pour the virus on the pillow -- carelessly -- and Clark splashes Virus X on his exposed skin.

The infection causes Superman to snap out of the hypnosis as plague symptoms develope. He tears off Clark Kent's suit and glasses, and Superman recalls the tragic history of Virus X on Krypton -- it had no cure, and no one who was infected expected to survive.

Luthor announces to the world that Superman is infected with Virus X -- he is the "Leper from Krypton". Superman proves to be highly contagious and people begin to fear the Man of Steel. An alley cat brushes against him, and instantly shrivels into a wrinkled mass of Virus X. Those in need refuse his help; and he is told to leave town. Clark visits the Daily Planet to leave a note and go, but Lois Lane catches him in the act. Would she catch Virus X as well?