Kathi,
There are mixed opinions about mixing. From what I understand, the most susceptible age groups are kittens and seniors, I didn't see if anyone other than Oreo fell into this group for you. I had to make a similar decision about my kittens (one positive, one negative) and decided to keep them together - the important thing for you about this decision is that if you keep them together and one or more turn up positive, will you be okay with that? As you can see from the board, if one does turn positive, it's not a death sentence and may not have any effect on their lives. I didn't see how long Ellie was living with the rest, but it is entirely possible that they have already been exposed and thrown it off.
My negative did turn positive, but I don't regret keeping them together as they seem to have a much higher quality of life together than apart. It's not an easy decision and you will get lots of opinions - just follow your heart!
Maggie
