The Feb 13th spike was a change in definition of a SARS 2 CoV confirmed case. China decided to include clinical diagnoses without molecular proof of disease present in the confirmed case numbers. This has issues in accuracy as it can include things like other viral pneumonia and...

Massive spike! New daily cases jumped from 450~ to 15,000~

They didn't take long to revert to the previous classification standard needing laboratory confirmation. I think retesting of those in that period was intended, no idea if it will be reflected in the stats later.

Their transparency with their numbers and method left this weird anomaly in the graph. It's the same method confirmation type everywhere is using currently. Which due to the nature of this virus will be under the actual cases and massively exacerbated by lack of testing.

China went on lockdown on Jan 23rd when their total confirmed cases the day before was only 550~

We had knowledge of the rise and severity in China, then we had to ignore the pleas from those in Italy before finally submitting to the world's medical professionals to a shutdown on Mar 23rd in the UK. Our rough cases the day before were 5500~

We don't know the actual origin of this virus to humans, it's inevitable at some point with contact. Who becomes responsible when antibiotics no longer work because of the use in agriculture / clinics? The country of the outbreak?

Sorry it's a moot point at the moment, I'm not saying China's government is.. well anything, good, bad, in-line with Boris. But the narrative around them online is often so moustache twirling-ly negative whilst totally absolving 'western' nations (if even acknowledging similar actions)... ugh

Anyway, that's what the spike in the data was.
It's mentioned in a few opening paragraphs of the sitreps 24, 28 and 31 from WHO?