Romans 5:12:

Wherefore, as by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned:

See also:

Where Did Demons Come From?
Objection: If We Are Subject to Death, We Are Subject to Sickness
Objection: Disease Viruses Are Part of God’s Creation and Are Therefore Good, Even Though We Often Don’t Think So When We Catch Them
Objection: God Gives and Takes Away