You know those little packets of tiny beads in cotton sachets they have in boxes of electrical goods? Well, those absorb ANY moisture in the box, for obvious reasons.
If you ever find one, just toss it into a sink of running water and watch and listen to the satisfying firecracker type noises (totally unrelated).
In other words, you joystick will not contain SARS. Unless of couse the funny packaging situation BlkPaladin mentioned actually happens.