Well, they said that they would continue, but that they don't expect to be able to track everything.

In fact from what I understand that have been able to track most cases.

Honestly, I'm guessing this is the case because they tracked the cases from original sources and then kept following them.

Being good at tracing could also explain why the number jumped so much. Tripling in 3 days, maybe it's easy to find cases if you trace contact :D