thankQ, lyby!
Looking BTT, heres a couple posts about how they isolate the variants; thread topic is the Mu variant:
https://freerepublic.com/focus/f-news/3992893/posts
Someone asks how they can tell what variant is going round:
https://freerepublic.com/focus/f-news/3992893/posts?page=14#14
Answer with some links:
https://freerepublic.com/focus/f-news/3992893/posts?page=16#16