COVID-19: MOBILE TESTING DAY 3 - THE TEST

I had a swab test today.  I hadn't booked, but was invited when I talked to a staff member at the mobile testing station.  This had been set up temporarily in a car park at the back of my local Tesco's.  This was on day 3 of their visit.  Here is Day 1 and Day 2.


I was promised the result within 24-48 hours, as processing the test in the lab is complex.

Update Monday 31st: Result through as "Negative".  15.5 hours turnaround overnight.  Very good!  Here's some of the email I received, from which relevant parts are written out below:

THE RISK OF FALSE NEGATIVES

A negative result is good news.  But is it correct?

We know that swabbing done by a trained professional can result in false negatives of up to 30%.   The test processing is reliable, but swabbing isn't.  "It’s a swab that requires some experience to do well". 

In my case, I had to self-swab.  Untrained, I'd probably be less effective at swabbing.  Higher risk of false negative. I'll be better next time (if I really develop symptoms), but could have done with a practice run this time with a spare swab.

The instructions had been written for the main testing stations, where people tend to arrive by car.  Sometimes a professional will do the swabbing there, but the instructions were for self-swabbing.  Small typeface, poor diagrams.  Illegible, without my reading glasses . Could have done with page headings, such as "Preparation" and "Swabbing". Good job I was supervised.

I haven't seen the instructions for self-swabbing at home.  But without someone to supervise, even more chance of poor swabbing and false negatives.

"Touch your tonsils with the swab" I was instructed.  Sadly I had them removed age 6 (and that's another story!). Was what I did right?  Then up the nose.  Again done correctly?

As I said, I could have done with a practice swab.  Often people want to gag when it is put down the throat, but it's no problem doing it twice.

I was also comfortable being in full view of passers-by, there were so few.  

In summary, I was simply unconvinced I had done it properly.


THE CONSEQUENCES OF FALSE NEGATIVES

The email I received advises I should still self-isolate for 14 days if "someone you live with tests positive or you've been traced as a contact of someone who tested positive."

However "If you're not a contact [of someone tested positive] you may return to work if you've not had a fever for 48 hours and feel well" or otherwise get back out living 'COVID-normally'.

At least until I show symptoms again, when I should "get tested and self-isolate for 10 days from when they start".

So it seems I should self-isolate for 10 or 14 days if there's any doubt.  I would also need to wait 2 days after fever or feeling unwell, which is a typical time for any other type of illness.

So that minimises the consequences of false negatives.  Provided people follow these instructions.  But what if they don't?  People on zero-hour contracts and the self-employed will tend to work through being ill, not only to avoid losing income, but to avoid losing their jobs.

Sweden's chief epidemiologist, Anders Tegnell, is against masks on balance for a number of reasons, one of which is that people might think it gives them a licence to go out and about despite symptoms.  This is a false concern:

• Anyone coughing or sneezing is immediately showing they are symptomatic.  The last concert I attended before lockdown was amazingly quiet.  Nobody dared cough like normal.  But if you've got COVID-19, you may not be able to help it.
• If someone has a temperature or just lost their sense of taste or smell, isn't it better that someone out and about should be wearing a mask to minimise the chance of infecting other people?        

SUPPORT ARRANGEMENTS

Asking people to self-isolate is a big ask, especially if they could lose income or even lose their job.  If they have young kids, how will they get them to school?  Will people take the risk?  Bet they would!


Scotland realised this all early on, and so their 'Test and Trace' was originally called "Test, Trace,  Isolate, Support", now known as "Test and Protect".  It includes "we will make sure that support is available to enable people to isolate effectively" meaning:

• "For some people, somewhere to isolate away from the rest of their household."  Studies have shown the obvious, that most infections are contracted from family and housemates at home.  Especially for the over-crowded houses often found for immigrants who are staffing our food factories, where there has been major breakouts.
• "Practical support with food and medicine"
• "Ensuring their physical and mental health needs are met. 
• "Any necessary financial support." subject to fudns from UK government.  These do not appear to have been forthcoming

In terms of food factories "The virologist said the virus remains on surfaces longer in the cold, it can be difficult to socially distance in factories and many of the workers may live together or not be keen to report symptoms as they need the work."  Just as I said.


England has just started a trial in parts of the north-west, where infection rates are high,to give extra money for "those those who claim Universal Credit or Working Tax Credit".But at only £13 a day, that's only £130 for a 10-day isolation or £182 for 14 days.  Better than nothing, but enough to make a difference whether people ignore restrictions?  Unlikely.


THE BASIC TEST PROCESS

Getting back to the basic test process, I was pleased that the result came through first thing this morning.  Yesterday would have been better.  But that would require a change of testing technology, albeit still likely to be based on swabbing.

As someone who has designed complex inter-departmental business processes, it takes real skill for Serco to screw up such a simple process.

Each person tested needs to be provided with just three pieces of information for them to complete their registration for their results on the internet:

• Test reference number
• Web site URL address
• Postcode of test centre, the first question the website asks

The test reference and the URL were on two different cards.  The postcode wasn't provided.  Postcode for a car park?  I typed in the first "outward" portion of the area.  No, wouldn't work.

Found a possible postcode, and all the sites were listed within about 10 miles.  Isn't the outward portion enough to list at least some of them?  It is on other websites.

Got there in the end.  But doesn't reflect well on the overall organisation of Serco's side of Test and Trace.


COST-EFFECTIVENESS

Each swab test costs around £100.  Presumably including lab time and personnel.  The total cost of testing must be enormous.  I would expect far better for this sort of money.

Clearly this level of expense is not sustainable.  There are cheaper tests in development.  But the only way of getting the need for testing down is to get the level of infections down.  Another reason to go 'COVID Zero' or #NearZero .



NUMBERS OF PEOPLE

Yesterday I was told "hundreds" over the 2 days.  Today I was told over 400 over the three days.  Not sure how many of these were actually symptomatic, given my own invitation.  But indicative of a major problem here nonetheless.

As discussed yesterday the estimate is that some 180 people are out and about infectious without realising it in this City, which is now on Amber Alert.

That's a mile away from #NearZero


IMPACT ON NHS STATISTICS

One question on the online registration is what is the postcode for the person tested, suggested to be where registered for a doctor.  It raises the question whether the NHS statistics for "new confirmed cases" are for the test location or this answer.  There's also whether cases identified first in hospital are recorded in the area of the hospital or the address of the patient.  I shall try to find out.

Increased testing also has two other impacts:

• Is any increase in cases, at national or local level, simply due to increased testing?  Clearly this will happen at local level when these mobile units are wheeled in.  But at national level, testing levels have remained pretty consistent during August.  But something to look out for.

• The total number of new cases has been estimated nationally at five times the reported "New Confirmed Cases".  This is mainly due to routinely only testing some of the people symptomatic, and completely missing asymptomatics who can still be carriers and infectious.  Identifying a higher proportion of these people means that the local figure at extra-test areas should be reduced to maybe 3 or 4.  But it may mean other areas need to be 6 or 7 to keep the national average.  That higher level is what would be expected if only symptomatic people are tested.

ON THE WAY HOME 

I've also been critical of the government's publicity campaign.  So it was refreshing to see posters up at the end of my road, looking like this:

Been there a while, by the looks of it, as it mentions Eid that was at the end of July.


IN CONCLUSION

Being tested is straightforward, but getting it right is difficult.  A spare swab to practice would be useful, plus clearer instructions. 

That would help to reduce false negatives arising from poor swabbing.  Whilst that isn't as much risk to people being incorrectly released into the community as I feared, that depends on whether people actually follow instructions to self-isolate when they should.  But false negatives would be a waste of £100, and understate "Confirmed Daily Cases".

The administrative process was not impressive, even when having been set up quickly.  Indicative of what goes on behind the scenes?

This isn't a process that could be scaled up to national level.  Reagents availability and testing cost would be prohibitive, if nothing else.  Wheeling in extra testing capacity like this would only work with far lower infection rates.  That's one of many reasons why we should aim for #NearZero .