This was the diagnosis they just gave my grandson! Finally found it listed under the 'rare diseases' category of the site I was searching.
They said about 9 out of 100,000 will be infected - and the symptoms absolutely fit what he's been suffering - his was increasingly swollen lymph glands in the side of his neck.
It's contracted from the lick, bite, or scratch of a cat, but can also come from cat fleas.
I'd been worried - they had been running this test and that on him, and I had no idea what it was going to come back as.
My DIL has cats - several of them - and I'm hoping that now they will cull the herd!