No, you do not need to throw away :)
What I did, even though it is not contagious I acted as if it were like a plague...
Hot HOT water, and vinegar (50/50%) is what I used since I am allergic to bleach... You can use bleach. Not 50/50 of course
Just a small amount. Clean all the fake plants and ornaments in scalding water, and bleach solution.
Toss the gravel... Even though it can be cleaned, I never risked it. Rinse everything a heck of a lot, until you feel it is safe to let dry, and refill.
Clean the heater with a damp hot rag with the bleach solution, then rinse it well under luke warm water. If there is a filter, clean it out and get a new cartridge even. I wouldn't chance anything.