How can you tell we are free (of Covid-19)

We had a record day on 1 Jul when there was no case among the people in the country. There was one case but it was imported

So are we back to normal?

The chart below shows the weekly number of cases since the end of Feb.

You can see that the number of cases is coming down but it was not a direct decline as there was a reversal in the latter part of May. 

There is no guarantee that just because it is now going down, it won't go sideways or even rise again. 

 

The risk is because not all the economy has opened up and as we open up schools and relax public gathering, we are introducing new ways to spread the virus.

 

BTW, my interpretation of the chart in the context of an epidemiological model is that if a group of infected people spread it to a smaller group (because the infected ones are isolated in time from the healthy people), then you will have a reducing pattern like what we are having in Malaysia.

The reverse is happening in the US ie a group of infected people is spreading it to a larger group, (what the epidemiologist refers to as R0 > 1 scenario).

But to come back to my question.  How do you tell that we have reached a “normal” or safe situation? 

The table below shows the number of cases for the last 2 weeks of Jan, Feb and June (I chose 2 weeks to peg it to the incubation period).  

           Total cases for the last 2 weeks

Jan                8  all cases

Feb               8  all cases

Jun            101  cases excluding imported

If you look at the current cases, it is nowhere near the 8 cases per 2 weeks for Jan and Feb of this year.

Do you remember that Jan and Feb was a time that while we kept hearing of cases in the country, we all went about our lives without worrying too much about it? 

 

I think this should be the “standard” we should strive for. 

When we have less than 10 cases continuously for a 2 week period, then I am ready to celebrate.

BTW New Zealand had 24 cases during the last 2 weeks of Jun.   Remember that the NZ PM had announced that they have eliminated the virus after about 3 weeks without any cases.  Then a day or two after the announcement they had 2 imported cases.

Not so easy.  

So in my mind, we have still some time to go.  And to reach this, we have to continue to cut off the source of infection. 

If you look at what is happening there are two sources of infection

• Imported cases
• Local transmission

I discussed yesterday how most of the world still have cases going up and so if we want to eliminate the imported source of infection,  we should continue to either ban travel (to and fro) for these countries or have mandatory quarantine for such places.

 

The self-quarantine should only be for those countries where the number of daily cases is going down.

As for the local transmission, I think that if we are going to relax public gathering, we must make masks part of the conditions.  

SOP without having mandatory wearing of masks is not the way to go

We seem to have 2 SOP focus currently – to help contact tracing (eg registering people, downloading the apps) and preventing the spread (social distance, public hygiene).

If we are going to have public gathering then we need to tighten the prevention part - we are introducing risk (crowds, enclosed places, spending a long time together) so where is the counterbalancing measure?  

Washing hands and social distancing is not sufficient.  I think that wearing a mask has to be mandatory for gathering.

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PS: This blog is for me to better understand COVID 19 as this will impact my investments. If you are also into equities, follow me at i4value.asia.

Disclaimer:  I am not an epidemiologist, healthcare worker, pharmacist, or staff in the Ministry of Health, but rather is someone with a strong interest in numerical analysis.  The content is an attempt to understand what is happening in the battle against COVID 19 from a data-based perspective. The opinions expressed here are based on information extracted from readily available public sources but I do not warrant its completeness or accuracy and should not be relied on as such.