It's up to you, I used to throw mine away but there are some that I really love that I just don't want to toss, so I keep them apart from my others and am super careful when handling them. These are also plants that I would never give or sell to anyone else...
some orchids have virus and you cant even tell....unless you test it....yet they continue to produce beautiful flowers(some flower shops have virused orchids and they don't even know).....if you used a test kit and found out your plant has a virus= you have to isolate it from the rest of the healthy plants....and yes you can toss it but make sure its not in the regular thrash it might contaminate the environment=use a biohazard bin(which you can find in hospitals and clinics)
Are there any visible signs an orchid has a virus?
Here is a link that could help you. Sometimes it is hard to know if it is a virus or fungal/bacterial issue. Color break in a flower is a sure sign. I would never purchase an orchid with color break.
Color break may be a symptom of virus, but not always, so don't rely on that alone . It can also be a matter of issues with culture and also the compatibility of parents that were used in making the cross.
The best ways to check for virus is a in home test kit, but even those can give a false reading if not done properly. Or you can elect to sent a sample out to a professional testing faucility which is certainly more reliable.
Best to keep any plants in question isolated until you get confimation of virus and always use safe handling practices to avoid further contamination of others.
Don't forget pests can spread viruses & diseases too.