LAMP test for SARS-CoV-2 being Piloted in UK Hospitals and students to reduce asymptomatic transmission.

[Jm954]

"A technical and clinical evaluation has confirmed OptiGene RT-LAMP tests to be accurate and sensitive enough to be used for COVID-19 testing, including for those without symptoms."

Loop-mediated isothermal amplification (LAMP) is a single-tube technique for the amplification of DNA and a low-cost, rapid alternative to RT-qPCR, the usual method of testing for covid. Reverse Transcription loop-mediated isothermal amplification (RT-LAMP) combines LAMP with a reverse transcription step to allow the detection of covid RNA. The target sequence is amplified at a constant temperature, unlike the usual RT-qPCR method. Typically, 4 different primers are used to amplify 6 distinct regions on the target gene, which increases specificity. Additional pairs of “loop primers” can further accelerate the reaction and the amount of amplified product produced in LAMP is considerably higher than PCR-based amplification.

The test was found to have a sensitivity of 79% and specificity of 100%, meaning the test is effective in identifying the cases who are infectious and are most likely to transmit the disease. In samples with a higher viral load, the sensitivity of the test increased to 94% for saliva and 100% for swabs.

Professor Keith Godfrey, of the University of Southampton MRC Lifecourse Epidemiology Unit, who led the first phase of the Southampton saliva testing pilot said: "The saliva LAMP project in Southampton has proved to be very easy for students to use, and is extremely popular with parents and staff. Participation among University of Southampton students has been very encouraging, with 80% of students in halls of residence and over two thirds of those in private accommodation registered for regular saliva LAMP testing.

Targeted educational materials and effective continued engagement with the students and school staff have been an essential part of the programme’s success, supported by well-developed laboratory, IT, enquiries and case contacting systems. During the pilot, with regular testing and participation rates exceeding 80% among the school staff and students, there has been no evidence of any transmission of infection within the schools involved. Feedback from students, staff and parents has been amazingly positive."

There is no information about if this testing method will be made more widely available to the public in the same way as the lateral flow tests.

The Department of Health and Social Care report (Dec 2020) is here:

gov.uk/government/news/clin...

The technical report is here: gov.uk/government/publicati...

Jackie

[Psmithuk]

Sounds more accurate than LFT 🤞

Thanks Cx

[Qwerty77 in reply to Psmithuk]

Actually, the LFTs have shown to be significantly more accurate than the media was trying to portray - and hence make it headline grabbing......They are designed to be used on people with no symptoms and are doing what they were designed to very well

[Psmithuk in reply to Qwerty77]

That's interesting, thank you.Cx

[bennevisplace in reply to Qwerty77]

One of the more critical reports on LFTs came not from the media but from the BMJ after scientists at the University of Liverpool found LFTs in the real world missed half positive cases (PCR controls). bmj.com/content/371/bmj.m4848 What's the evidence they perform better now?

[Qwerty77 in reply to bennevisplace]

This is from the end of 2020. More data/studies are available now.

ox.ac.uk/news/2021-07-14-la...

There’s a few studies - I’d have to try to find them - but we were discussing it recently at work within the CCG and the general consensus is that they are actually a really useful tool; especially for people who have no symptoms inadvertently being positive and spreading COVID. The regularity of their use is fantastic - something that could not be managed by twice weekly PCR tests for the millions of people in the UK.

They obviously pick up symptomatic patients; and could effectively be used for that - however, PCR’s need to be done so that we can document and record formally the positive results and do the genome sequencing - which can’t be done via LFT’s

If anything a lateral flow might show a false positive - which whilst not ideal; I’d rather it be this way around as the person could follow this up with a PCR

[bennevisplace in reply to Qwerty77]

Thanks, I hadn't seen the Oxford study. It shows that LFTs can be effective if used intelligently, and they are cheap /free, fast and available (I say cheap, but uk gov has spent upwards of £2 billion on them). One intelligent application is repeat testing - say 3 times a week - to screen people before going to work. Having said that. the test period in the Oxford study was pre-Delta and more importantly was confined to symptomatic subjects. The Liverpool study which I cited was population-wide, including asymptomatic positives, arguably more representative of performance in screening people coming and going (workforce, planeload etc) and the problem there was a circa 50 % incidence of false negatives - dangerous in the absence of other control measures. Also the Liverpool study tested only one make of LFT, Innova. That is still the one most commonly used in the UK I believe.

If we in the UK had not already achieved + 90 percent seropositivity in the adult population I would be extremely concerned at relying on a one-off LFT to screen allegedly-vaccinated travellers arriving from under-vaccinated countries, which is what will happen in 2 weeks' time gov.uk/government/news/new-... I wonder if this change is guided more by economic pressures than science. Fingers crossed we don't import another turbo-charged variant.

[Qwerty77 in reply to bennevisplace]

I really support the use of lateral flows....both at work and children’s schools - they’ve picked up asymptomatic people in pretty scary numbers.....anecdotally colleagues and friends have said when it turns positive there’s no mistaking it! I also think that the lay person will become more adept at doing the swans with practice.

I agree though with travel.....I think PCR is needed (as even vaccinated people are catching COVID and spreading it....I’ve heard of 3 today alone!)...my personal opinion is that NHS facilities should be used and a charge should be made accordingly....keeps all the data in one place! Take the charge off people before they board their flight home, otherwise no boarding.....

Other countries are not giving lateral flows out for free and I think they’re missing a trick......there’s personal responsibility....and free lateral flows are a way of encouraging this.

Even in Cape Verde - currently a RED country, which is crazy given some of the countries listed in the ‘OK to fly’ list has insisted on lateral flows when travelling between the islands of the archipelago (and have done since they opened their borders in Oct 20) charging €12 each - even in Africa - where the average wage is less than €300/month. There vaccination levels are pretty impressive as well!

[Qwerty77 in reply to bennevisplace]

One thing that is certain is there will definitely be more variants......not enough adults in the UK are being vaccinated....hence the need to try to jab 12-15 year olds....It’s irrelevant if we vaccinate 100% of the population - this will have no effect on preventing variants if other countries around the world have not managed to vaccinate their populations as well - so really, rather than giving healthy kids vaccines we should be supporting vaccine programmes around the world!

[bennevisplace in reply to Qwerty77]

Agreed, but we have enough vaccine to do both: vaccinate 12-15 yo's and make good NOW on our pledges to other countries.

[Qwerty77 in reply to bennevisplace]

The rest of the world needs many more vaccines than what has been pledged; unfortunately😢.....and they need the support, staff, infrastructure to administer them yesterday.....My daughter is 12 and she won’t be receiving the vaccine.....not yet anyway.

Vaccinating 12-15 year olds is not enough....to stop COVID spreading.....it’s likely enough to stop people becoming very unwell....which is my reason (as an adult for getting it) - but so far, young people are not badly affected (most seem to be getting a headache/stuffy nose for less than a day)

If giving a 12 year old would stop them catching and/or spreading COVID that would be different.

I wish I’d had AZ.....we’re seeing significantly less people catching COVID having had this jab; and those that are catching it seem to be getting over it relatively easily (old/younger/immunosuppressed included)

[LeoPa]

The inventor (and CEO of MultiplexDX) Mr. Čekan is from no other place than Slovakia

He's been decorated by our lady president this spring for the achievement. One of our brightest scientists!

multiplexdx.com/news

[bennevisplace]

Promising, though 79% sensitivity is still not great. Is this a realistic alternative to LFTs?

[Jm954 Administrator in reply to bennevisplace]

My former colleagues in the NHS who are using it think it’s much better than the LFT. As I said in the article, there doesn’t seem to be any plan to extend its use to the public. I think that’s a pity as the LFTs are made in China and that really irks me!!!

Jackie

[Justasheet1 in reply to Jm954]

Careful Jackie, you can’t be angry with countries or states or you might get in trouble 🤪

Seriously, why won’t they release it to public use; cost? The LFT test I buy here in the states is 2 for $15 which is cheap but is sometimes difficult to get.

Jeff

[Jm954 Administrator in reply to Justasheet1]

Hi Jeff

In the UK all the LFTs are freely handed out or available to order for nothing but you should report the results on line.