I have done rescuing for many years now, had hundreds of cats pass through the revolving doors here, and had only one obvious FIP kitten. If the kittens etc. I take in test FeLV- and have had a quarantine period for panleukopenia, if space allows, they can run to their hearts content. FIP is a member of the corona virus family, which the common kitty cold is also! Therefore, if you take your cat in for the so called "FIP test" chances are they WILL test positive! Most every cat has had a cold by the time they reach a year old, and the test only detects a corona virus...not an FIP one. Vets cannot differentiate between any corona virus, and more cats are killed by that damn test, than actually die from FIP! Breeders of cats tend to get FIP positives more than the general public, as it is linked more by genetics, than not. I panicked when years back I had one little black kitten who developed the wet form of FIP. His lttermates had all been adopted (and all to my knowledge are fine still), but this kitten had the classic symptoms, lethargy, abdominal bloat, anemia, and a very spiny blow fish look about him. I took him to the vets where he had a belly tap...banana yellow fluid came out, and I chose to euthanise him as he was going downhill. He exposed many others to this virus. According to "Catnip Newsletter" put out by Cornell Univ. FIP can live outside the body for six weeks or longer under ideal conditions, it generally survives only a few days, and is easily killed by common disinfectants. It is more genetically linked than not, and many cats can be exposed and never show any symptoms. About 5-10% of cats exposed come down with the full blown virus, and die from it. I'd tell your friend to clean the place well, and adopt a shelter cat or kitten...or two! And not worry!