Coronavirus Analysis (part 1) - How long will lockdown last?

Some very basic analysis based on the figures available from wikipedia.

CHINA

NUMBER OF NEW CASES AND LOCKDOWN

Here's a chart of new cases in China by date. The outbreak was centred on Wuhan / Hubei with 80%+ of cases coming from this area.

_{China new coronavirus cases by date
Figures sourced from:
https://en.wikipedia.org/wiki/2019–20_coronavirus_pandemic_in_mainland_China}

Lockdown started in Wuhan on 23 January and other Hubei cities on 24 January. There was an exodus of people from Wuhan just before the lockdown which may have weakened the quarantine and allowed further spread of the disease.

Looking at the new case numbers there is an initial levelling around the 11-14 day mark (after lockdown) followed by a general decline in cases with some later spikes. These spikes may be down to issues with changes in the approach to measure the number of cases or possibly the imperfect quarantine noted above.

New case numbers fell below 100 on 6 March. The lifting of the lockdown in Hubei started on 13 March, 49 days / 7 weeks after the lockdown started. The lifting of the quarantine in Wuhan is happening now, representing 9 weeks of lockdown.

NUMBER OF SICK PEOPLE

It's worth also looking at this chart, sourced directly from wikipedia:

_{China number of sick people by date
Figures sourced from:
https://en.wikipedia.org/wiki/2019–20_coronavirus_pandemic_in_mainland_China}

Interesting points to note are:

• Although new case numbers had fallen to 200 by 1 March, the number of sick people at this point was 33,000 and there were still 10,000 sick people on 15 March, 2 weeks later. I think this has implications for the length of any lockdown.
• The peak in numbers of sick people (and deaths) appears to lag the peak in the number of cases by about 1 week. So the heaviest strain on health services will continue for a week after the lockdown has caused a peak in new case numbers.

SUMMARY

So a timeline summary based on the above:

• Lockdown period to peak of new cases: 2 weeks
• Lockdown period to low number of new cases: 5 weeks
• Lockdown period to potential lifting of quarantine: 7 weeks (although many people still sick in hospital at this point)
• Full lockdown in hardest hit areas: 9 weeks

China's quarantine was probably pretty well enforced. So applying these figures to other countries assumes the same stringency of lockdown. On the other hand, China suffered the virus first and other countries should be able to learn some lessons and benefit from advances in technology, in particular testing, to assist in handling the outbreak.

In part 2 I'll look at some European countries and use the figures from China to project what happens next in these countries