Cattleyas tested positive for viral diseases. How upsetting!

[babehauss]

Three of my Cattleya plants tested positive for the virus (using Agdia CymMV&ORSV test kits). The flowers on these plants are not affected at all, but the leaves showed black spots or streak marks.

I have not tested the rest of my other orchids because none shows any viral symptoms or signs on the leaves (no black spots,no rings, no streak marks). Should I test the rest of my plants if they show no signs of viral diseases? These tests are not cheap.
How reliable are the CymMV&ORSV tests?

Thank you,