[Felvtalk] help /advice - testing age of kittens

[Anna Summers]

Hi , I live in spain in a very rural are  & last year I lost 2 cats  who were felv +  , they were not in contacted with my house cats  but one of  them  ( 9yrs old )  is  latent  positive DNA  with a low reading of the virus ,  I did a quantative  pcr  , he was negative in the elisa test and I was told that he is not contagious . my other 2 cats are vacinated  against fel.
my question …..
As I see yourselves are up to date with all the latest things  - someone  left a kitten on my wall just before christmas - he is now been in “ quarantine” for 5 weeks , he is about 4months old , I need to test him  but when is the right time to test kittens as I have read many article re: the anitbodies of the mother so a kitten can test false positive.
I am keen to know , as he is on his own and hopefully he will be negative  so I then can vaccinate him  as I am also told that, are they any special test to do this , I dont want to do the basic snap test and I am happy to do the elisa and a pcr test.
Hope you can help me , here in the area a live in which is very rural ,lots of ferral cat  the vets  just give up on felv + , so I dont wont to ask my vet  until I am up to date with all the information.
thank you 
anna