I can't tell if the statement is serious or not

The Wuhan mayor has already admitted himself that they did not undertake proper measures to control the situation and here they are declaring that it is a "success"?

I think there's little doubt that the statement is meant to try and defuse the fear-mongering over the virus outbreak but this is a bit of an overstatement considering how there were cases already being reported as far back as December.

I reckon it is but sheer luck that the virus had not mutated into something that could be more easily transmittable via person-to-person interaction.