What is the implication of a 3:1 ratio of infections between foreign workers and Malaysians?

We had 78 cases yesterday that can be broken down into

• 25 imported/returnees
• 40 foreigners
• 13 local transmissions

The weekly chart does not paint a good picture going into the Raya holidays since it points to an upturn for week 10 of the MCO c/w the previous week.

25 of the foreigners were from the Bukit Jalil detention centre bringing the total from this cluster to 60 cases so far.   MOH had reported the day before that it had tested 645 people from this centre.  Unfortunately, there is no information on how many people are detained there so we do not know whether this is the end of the story from this cluster.

The FMT reported various parties voicing their concerns about the risks to new detainees being brought to this centre and are asking Putrajaya for a moratorium on the immigration workers raids. There was also concern about the risks to those working there. I suspect that there will be more cases from this cluster.

The increase in the number of daily cases due to the foreign workers is not something unexpected.  We can debate whether there would be any difference if the cluster was centred on the detention centre or the foreign workers' residential areas.  I would have thought that social distancing would have been a challenge in both situations. 

The main point I want to make is that based on the number of cases since the middle of May, we are having a ratio of about 3:1 in terms of the number of daily cases among the foreign workers c/w Malaysians as can be seen from the chart below.

If this trend continues, it means that more of the treatment resources would be utilized by the foreign workers.  It may be ironic, but we brought in the foreign workers to boost our economy and now it looks as if we will have to expend more resources to take care of them.  This is of course  similar to what is happening in Singapore.

But there is a silver lining to this ratio.  My hypothesis is that it would be easier to control the virus among the foreign workers than among Malaysians.  Historically the foreign workers' clusters tend to be

• Location/residence-based OR
• Employment-based

This concentration makes it easier for the authorities to contact trace them when an outbreak occurs eg many of the foreign workers' residential areas and workplaces have been EMCO.

But when it comes to Malaysians, we run all over the place.

To illustrate what I mean, MOH said yesterday that it had ramped up testing in Kelantan, Kedah and Terengganu after new cases were found in places that have been green zones for some time.  MOH attributed the Kelantan case to a woman who traveled from Ampang, Selangor.  She visited several places to meet up with friends and relatives before arriving at her village. MOH had tested 30 of her family members so far and I am still waiting for news on how many of her friends would eventually be tested.  This mobility is in contrast with foreign workers.

The main concern of course is with event-based clusters like what happened in the Sri Petaling where some of the foreign workers attended, it would be more difficult to trace them.  However,  I would like to think that we should not have such issues in the future as

• We still have a ban on public gathering
• For some of the permitted gatherings such as the religious ones, it is restricted to only locals
• Many public places now require you to record your contacts.  I went to the post office yesterday and was impressed with its SOP.  People had to queue outside with distances marked on the floor.  There was one staff member who took my temperature and sprayed my hand with disinfectant at the door.  Then I had to register before I could take a number.  And they placed the sitting bench against each counter so that you had a 3 feet space between you and the counter staff. 

So what is the moral of the story?  Just because there a are lower number of daily new cases among Malaysians does not mean that it would be easier to control the transmission among them.  Don’t focus on the numbers.  Focus on the distribution of the cases. 



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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. 

Can we have single digit daily new cases soon?

Yesterday we ended Week 9 of the MCO with an average of 33 new daily cases c/w with the average of 50 cases and 69 cases for Weeks 8 and 7 respectively.  We are definitely trending downwards as can be seen from the chart below. 




Note: the vertical lines denote the respective MCO week

On Tue May 19, MOH was reported to have said that Malaysia is on track to achieve single-digit daily new cases soon as the daily number remains below 50. Unfortunately, MOH did not provide a timeline for this single digit scenario.

My updated multi-layer curve fitting model projected that by mid-Jun 2020, we would still have about double-digit daily new cases.  From a charting perspective, the single-digit number of daily cases would be in late June or in July. 

I don’t want to be the party pooper but I think that as long as we continue to have Returnees, people waiting to be tested from the Tabligh, Tahfiz, and Market clusters, "achieving the single-digit daily new cases soon" would be challenging.

The other unknown is of course the foreign workers as we continue to have double-digit cases from this group. Over the past 1 week, the number of daily new cases among the foreign workers ranged from 5 to 31 cases with an average of 17 cases.   I have yet to detect any trend as can be seen from the chart below. 

With the Returnees, Tahfiz and Market groups, we know that the total numbers still to be tested for these groups is under 20,000 people.  Even though we don’t have the outstanding numbers for the Tabligh group, I am confident that they would be under 10,000 to be tested.   This means that the potential new cases from these groups have an upper limit that we can easily estimate. (Refer to posting Dark Clouds On The Horizon)

But for the foreign workers, the exposure depends on your view of the foreign workers' population in the country as can be seen from the table below

Category	No tested	Population	% of Population tested
Foreign workers	26,425	2 – 4 m	0.7 – 1.3
Malaysians	416,263	31.5 m	1.3

The optimists will say that as the number of daily cases among the locals gets to a single digit, we should have the same proportionate reduction among the foreign workers.   But I can imagine the pessimists saying we have not sufficiently tested the foreign workers and so we will continue to have cases among the foreign workers' community for a longer period after the cases among the locals get eliminated.

So are you an optimist or pessimist? 

The positive news is MOH saying that if the cases involving locals can be kept to 15 – 20 daily new cases, the public health team can cope i.e. don't have another MCO. 

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Be fearless to get more to Stay Safe, Share this Blog

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. 

How Informative Is The MOH Daily Briefing (Really) ?

Everyday MOH provides an update on the Covid 19 statistics (e.g. cases, deaths, under treatment, etc) <http://covid-19.moh.gov.my/terkini> and occasionally provides further details (groups tested, potential cluster size, etc).  Although I have been following the daily briefing in order to update my database, I think that they are of limited use to the general public from the risk mitigation perspective. 

I guess there are two perspectives of the information – those that help MOH do its public health job (e.g. contact tracing and isolating cases) and those that help the public avoid risks.  I think most of the information provided is more useful to MOH than to the general public as

• Cases are reported by State  – these are too large an area to inform the public as to which places to avoid.  
• There are statistics on the number of daily cases, those under treatment, etc – unless I am a healthcare worker, I am not sure how to use these for risk mitigation.
• Cases are reported in bits and pieces by target groups - I am not sure whether this is a fault of MOH or the media but I don’t think the presentation has helped the general public in avoiding the asymptomatic. 

As a member of the general public, I am more concerned about the risks of infection and that is why I have been re-casting and analyzing all the MOH information into a format that can inform me of where and the extent of the risk of being infected as well as when to do the next panic buying. 

Incidentally, I am very proud that on the weekend just before 18 Mac, my family went out for a good meal on the basis that it might be a long time before we could have one.  Furthermore, I did all my panic buying on the Sunday morning before the PM's announcement on the MCO.    OK, I might have been lucky but I hope my daily analysis can provide further guidance in the future!!

What do I want to see?

• Cases at a more granular level eg residential and business locations
• Projections of asymptomatic cases at each of the residential and business locations
• Alternatively, zoning at the granular level based on actual and projections so that we know that if it a green zone, we don’t have to worry.  

That is why I am upset when I see anomalies and gaps in the information provided.  My current concern is the testing figures.

President Trump said that testing is overrated and with more testing, you will find more cases.  I think OP WTC has posted some comments about how ridiculous his statement is.  But Malaysia is even more unique in that we can have cases reported without any testing as per below.

May 2020	No of daily cases	No of daily tests as per Worldodometer
11	70	14,784
12	16	0
13	37	0
14	40	0
15	36	152,585
16	17	9,830
17	22	9,127
18	47	0
19	37	18,994

Note:  Worldodometer reports the cumulative numbers every day so the daily figures are derived figures

OK, I may be facetious, but it does raise some questions why for the past 2 weeks there have been days with zero testing reported when we did not have this issue before.  I am assuming that Worldodometer picked up the testing figures from MOH - if so what is happening in MOH?

Considering that almost all the information on Covid 19 in the country comes from MOH, we should be worried about changes in reporting format by MOH.  I have previously posted that I switched my source of testing info from MOH to Worldodometer in early April when MOH stopped providing such statistics on its webpage.  This switch has not helped in getting timely information. 

The only positive news is that the number of daily tests seems to have gone up c/w with the 3,800 average daily tests in the middle of last month. 

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Be fearless to get more to Stay Safe, Share this Blog

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. 

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Dark Clouds On The Horizon ?

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Based on the past few days of daily cases, we estimated that for week 9 of the MCO, we will have an average of 32 cases per day c/w an average of 50 cases per day the week before. Are we seeing a declining trend?

I am afraid that there are some dark clouds on the horizon.  I think we have about 377 potential cases from the Tahfiz, Market and Returnee groups as tabulated below.  This is even before including the potential cases from the Tabligh cluster. 

The 377 projection is based on the people that have yet to be tested and assumes the same historical positive test rates for the respective groups.   I would like to think that the actual number of infected would be lower as it has been some time since these groups have been identified and some of those infected who were asymptomatic may have already recovered. 

Groups	No still to be tested	No infected at same % positive rate
Tahfiz	6,13	295
Market	7,539	68
Returnee	1,277	14
Total	19,878	377

As for the Tabligh group, MOH had been reporting an increasing number of people screened even though the index event was held at the end of Feb 2020.   FYI, there were 220 cases from the Tabligh cluster over the 19 days period from 28 April to 17 May so it is not a small number.

Date              Cum No from Tabligh cluster screened

28 April                      32,122

14 May                       38,679

17 May                       38,911

I suspect that the inter-state travel restriction and as well as the advice to keep the Raya visits low is because of the potential cases from the Tahfiz and Tabligh groups.  

The only positive news is that the total due to community spread over the past 3 months is 1,717 cases equivalent to 21 cases per day. 

The basis for the above projection is the table below where I have tried to reconcile the number of cumulative tests reported by Worldodometer as of 17 May 2020 with those of MOH targeted groups.  Of the 8 targets, there was no information on the testing and/or number of cases for the senior citizen group.  Ignoring the senior citizen group, we can draw the following conclusion about the targeted groups

• They accounted for 69 % of the total cases
• They accounted for 35% of the testing

Groups	Total tested (a)	Total positives	% positive (g)	Population
1.Tabligh	38,911	2,375	6.1	16,000 (b)
2.Tahfiz	13,636	658	4.8	19,771
3.Markets	29,594	259	0.9	37,133
4.Returnee	36,200 (j)	390	1.1 (j)	37,477 (c)
5. Foreign workers	26,425 (d)	1,037	3.9
6. Healthcare	11,470 (e)	65 (e)	0.6
7. Other clusters (h)	NA	381
8. Emergency surgery (i)	8.528	12	0.1
9. Balance/EMCO	278,499 (f)	1,717	0.6
Total	443,263	6,894	1.6

I cannot explain the balancing figures (ie group No 9) as the % positive looked very low relative to the % positives of other targeted groups.  The balance refers to community spread, EMCO areas and other clusters not specifically mentioned here.   Note the following

• I had assumed that the number of tests reported by Worldodometer refers to the tests carried out to detect new cases and exclude those for re-testing patients under treatment, etc.  I understand that out of our 26,700 daily test capacity, a significant portion is for re-testing of patients, etc and hence can account for why the actual daily number of tests for yesterday was only 9,127 c/w the capacity. 

• For groups 1 to 6, MOH actually reported the number of people screened which I interpreted to be equivalent to the number of tests i.e. 1 screen = 1 test.  I could be wrong.

•  Not all the information for the groups referred to the same date so there could be some counting error from this. 

Can anyone throw more light onto this breakdown?  Am I wrong to interpret the number of people screen = number of tests carried out?

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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

Notes

a) As at 17 May unless stated otherwise

b) Supposedly the number of people who attended the Sri Petaling event.  The number tested included contacts

c) Total quarantined as at 18 May of which 29,279 have completed their 14 days quarantine and 390 tested positives

d) There could be double counting for the total tested with those in the Markets clusters although the total positives seem to be an independent figure

(e) As at 12 May.  This is inconsistent with the 28 April report of 6,838 screened with 372 positives (5.4 % positivity).  If we assumed the 372 positives, we would have a lower balance figure.

(f) Assume that the foreign workers are deducted from the total

(g) Detection rate defined as number tested positive divided by total tested

(h) These are clusters that are clearly not linked to the other groups listed ie Church, Wedding, Case 26, Italy = 381 as per Malaysiakini.  There is no report on the number of people in these clusters that were screened

(i) MOH reported that all those emergency cases in the govt hospitals needed to be screened before surgery

(j) The % positivity was based on 28 April report and was used to derive the number tested

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. 

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