Belle tested positive for FIV. This means at some point she has been exposed to Feline Immunodeficiency Virus. Or she could have antibodies from receiving an FIV vaccination in the past. Since her previous owners abandoned her without sharing that information, we don't know, so we have to treat her like she is actually carrying the virus.
FIV isn't all that scary. It can't be transmitted to dogs or people, and it can only be transmitted from cat to cat via a deep bite wound or blood transfusion. Most cats with FIV never even show symptoms - they live long, happy, healthy lives. But when there are thousands of other cats to choose from (literally - there are over 1,500 cats available for adoption within 100 miles of me right now), people tend to overlook the cats with special needs or the cats who test positive for FIV. Some rescue groups euthanize cats who test positive because their odds of getting adopted are so much lower. But the rescue group I volunteer with doesn't do that, so Belle is going to live a long happy life. Of course she's stuck with me until she gets adopted, so it may not be as happy as she wants.
In the worst case scenario, FIV can cause Belle's immune system to stop working as well, and she could become seriously ill from an infection or illness. But I've decided that she is going to be one of those cats who never shows symptoms. (yes, it's just that easy). She can't stay at PetSmart because the cats are allowed to interact with each other, and there would be a risk of her getting in a fight and spreading FIV to another cat. So I take her to adoption events on the weekend, but the rest of the week she is here with me.
I tend to have a bias against calico and tortoiseshell cats after fostering Scribbles and Whisper. Calicos and Torties in general are known to have more "cattitude" than other cats. There's no scientific basis for it, but in my experience, it's true, so I actually almost didn't take Belle from the shelter just because she was a calico. But I'm so glad I did take her - she's one of the sweetest cats I've met. She's started sleeping with me every night and she is so affectionate. I hope that some adopter out there will see what a wonderful cat she is, and give her the forever home that she so deserves.