Covid19 - Why lockdowns failed

China was the first country that imposed a lockdown on big cities like Wuhan with a population of about 15m and the whole province of Hubei with another 50m population. And the effort bore great results with the Covid19 virus contained and as good as obliterated in 3 months. No more local transmission, Hubei unlocked and Wuhan about to be unlocked with life starting to return to normalcy.

Many countries have also followed China's example of locking down cities and region but are failing. Some countries like Singapore, South Korea and Japan did not really lock down their country or cities but seem to be doing fairy well.  Why are the western countries failing, especially Italy and Spain, and why locking down American cities would also failed?

There are three fundamentals that would ensure some kind of success in a lockdown. A lockdown is a stringent measure that aims to contain the virus in a particular spot, city or region. When announced, no one leaves or enters the area. And it is pointless to announce a lockdown in advance to allow people to leave quickly. Those who left would bring along the virus in them to spread wherever they go. This was exactly what happened to Italy. You don't announce a lockdown in advance to allow infected people to leave before it comes into effect. After a lockdown, in China's case, all the few  cases outside Wuhan and Hubei were quickly tackled and isolated to prevent further spread.

Now Trump is going to do a lockdown on New York. Would it work? No, it is too late, the virus is all over the USA. This brings me to the second fundamental, to nip the problem in the bud. When the problem is small and contained, it could be killed on the spot. This means cornering the virus by contact tracing, quarantine them and testing all those that have come into contact with the infected person. In this way, the spread could be arrested and any one that missed contacted, when infected and reported, the whole process would swing into action again to bring all those in contact with the infected person into quarantine. This is where Singapore did well, swift enforcement when the problem is small and not allowed to grow and spread. This was also the case in other parts of China after Wuhan was locked down.

The third fundamental is testing. In a lockdown, the virus is contained in an area. Infected person isolated, suspects quarantined and tested. And because infected and suspected are identified and confined, there is no need to test the rest of the population. They would  only be tested when infected or suspected to be infected. In places where there is no lockdowns, the problem is not contained, and worse, if there is no testing, those already infected would be spreading the virus everywhere they go. This is the problem in countries that introduced half hearted measures in lockdowns and testing only those infected. The virus was having a great time, unrestrained and spreading freely. Oh, the test must be free or minimal cost to get people to come for the test.

Today, many countries have the virus all over. Any forms of lockdowns must be nation wide, like the whole of Italy or the whole of the USA, the whole of UK, to be meaningful and effective. And after the lockdowns, isolation of infected, quarantined of those they have contacted and testing everyone of them must follow to restrain the virus from spreading further. No testing, no contact tracing, no quarantine, no lockdown, no success. To contain and stop the virus from spreading means serious effort to contain, no half hearted measures as the virus would spread freely given the chance.

PS.  Lockdown is completely useless when the virus has bolted. Trump would not be able to comprehend this simple logic.