That's a tough question. I'd suggest you better ask your vet for that info.

As far as I know, the FIP ELISA test isn't very reliable. It will only tell you if there has been an infection with a corona virus, but it won't tell you wether it's the FIP virus or another corona virus (to which many cats are exposed).

When I got that right, Isabel has only lived with you and Zelda for two weeks, right? To be on the safe side, I would remove or at least disinfect the things Isabel has used. The virus can survive outside the cats' body for several weeks.

Maybe you can find some comfort in the thought that not every cat that was in contact with a FIP cat will get the disease.

I hope you won't have to wait too long before you can get Zelda tested - and that the test will be negative!

Kirsten