Using a Covid-19 lateral flow self testing swab

Thank you to everyone who has been involved in our first 12-week lateral flow testing kit programme. To date we have received over 50,000 test results and identified 646 asymptomatic cases of Covid-19. This team effort has helped to keep us all safe and we are seeing almost no staff-to-staff transmission.

Even with case numbers decreasing and the number of people being vaccinated increasing, it is important we continue to test ourselves regularly. Infections (especially asymptomatic infections) are still possible, and testing can help reduce the risk of transmitting the virus to your colleagues.

Please remember you still need to follow PPE guidelines at work and during your travel to and from work if your lateral flow test is negative or invalid. The lateral flow test has a lower sensitivity compared to PCR and means some positive cases will be missed with this test. It is therefore vitally important that staff still follow all the trust PPE guidelines.

Introduction to the test

Why are we testing staff without Covid-19 symptoms? 

We know that some people have Covid-19 but do not display any symptoms. Although they remain well, they can still transmit the virus to others, including colleagues and patients. While excellent use of PPE should reduce this transmission, there is a still a risk. Staff who have Covid-19 should not be in the workplace and should self-isolate according to government guidelines to minimise the spread of infection. 

The key objectives of testing asymptomatic NHS staff for SARS CoV-2 are to:

  • Help reduce transmission of SARS CoV-2 in hospitals and onward transmission back to the community
  • Reduce episodes of staff absenteeism particularly in relation to quarantine following contact with a COVID-positive colleague or patient
  • Support the NHS in its infection control risk reduction strategies to protect patients and staff.

Why are we using the home LFD kits and not testing by PCR? 

The current gold standard in testing for SARS CoV-2 infection is the PCR test. NHS capacity for PCR testing is limited and mostly reserved for patient testing and testing of staff with COVID-19 symptoms. 

There is a national drive for regular mass testing of asymptomatic, patient-facing NHS staff for reasons outlined in the objectives above.  At this time however there is not enough availability of the PCR tests to allow it to be used for this mass staff testing. Therefore, alternative technologies and strategies are needed. The Innova SARS CoV-2 Antigen Rapid Qualitative Test is an immunochromatographic test (immunologic test where the results are shown by a change in colour of test lines) that detects antigens from SARS CoV-2 in human nasal swabs. It is the first LFD to successfully pass through all stages of Public Health England (PHE) evaluations, and has been evaluated in a number of settings including secondary healthcare settings, PHE Porton Down, military establishments, schools and universities  Most recently it was evaluated for mass community asymptomatic testing at regional Covid-19 centres in Liverpool. 

Will this LFD test find all staff with asymptomatic Covid-19?

The test has an overall sensitivity of 76.8% for all PCR positive individuals but detects over 95% of individuals with high viral loads. The lower sensitivity of this test compared to PCR means some positive staff will be missed with this test and it is therefore vitally important that staff still follow all the Trust Infection control and PPE guidelines. 

It has been suggested that the twice weekly testing, the ease of testing and the speed of the result may compensate for the lower sensitivity.

Although the false positive rate is very low, anyone who has a positive result on the LFD will be asked to undergo a PCR test for confirmation.

Why is the test insert that was in the box different to the instructions given to me by the trust and NHS?

The box contains a technical document from the manufacturers. Feel free to read this but it contains lots of information that may not be very helpful. The instructions in this ‘test insert’ may also differ slightly from the instructions we have given on how to perform the test. 

It is very important you follow the instructions we have given you.

Taking part in the self testing programme

Which staff will be part of the LFD testing programme?

The aim of this national programme is to test all patient facing staff twice weekly for SARS CoV-2.

We have received a further 12,000 kits and will roll these out to staff who have finished their first kit or are coming to the end of their first kit, and for any other member of staff who wishes to participate in the lateral flow testing programme. 

Staff must remember the best way of protecting themselves is always to practice good infection prevention and control, keep physical distance, wash hands, and wear appropriate PPE. The testing regime and test results do not mean staff can change practice when it comes to PPE.

If you were not able to receive a lateral flow test kit previously due to this and would like to receive one, please come to one of the hubs to collect a kit.

Is it compulsory to participate in the LFD testing programme?

No. Participation in this testing process is not compulsory but we would encourage all eligible staff to participate. Once you do sign up we however will expect you to participate for the full 12 weeks.

Getting your free lateral flow testing kit

How and where do I collect my LFD test kit?

At the end of June, the DHSC announced that with effect from the 5th July 2021, NHS Trusts would no longer be supplied with Lateral Flow test kits for staff.

Staff will now need to obtain their lateral flow test kits at no cost online or from their local pharmacy. Test kits from the local pharmacy or online contain 7 tests per box and a maximum of two boxes can be collected at a time.

Staff applying online for their lateral flow test kits can do so using the following link: https://www.gov.uk/order-coronavirus-rapid-lateral-flow-tests

For any questions about the new process please contact your site lead:

If you work for Serco or Linet you can receive a testing kit online via the same process outlined above. 

What do I do if my LFD kit is damaged, broken or has anything missing?

Report any damaged or broken kits to your site lead who will advise the best next steps to be taken.

What do I do if I lose my LFD kit?

Report any lost kits to your site lead who will advise the best next steps to be taken.

Unfortunately, we do not have sufficient kits to replace them if they are lost. Please take care to get your kit home safely and store it somewhere safe, away from children or pets.

Using the Infinity Health system

The trust has moved to the Infinity Health system for registering and uploading lateral flow test results, which staff should find simpler to use.

The system works by inviting staff via email to register on the Infinity Health system and once registered they will receive email reminders to upload their test results. 

When registering with Infinity Health, staff can choose to use a personal email address if they so wish. 

Having problems registering? Read our registration guidance: Infinity registration guide for staff.pdf 247KB

Follow these instructions to log on and register with the new Infinity system.

  1. You will receive a welcome email from noreply@infinity.health (please ensure to check your junk mail) to log on and register.
  2. Then consent to receiving automated email notification reminders to log in and submit lateral flow testing results on the days of the week you select.
  3. Please ensure that you fully register, including identifying the main site you work at, before collecting your latest test kit.

Not receiving any emails from infinity after registering - check your junk!

Testing of the Infinity Health system showed that emails to staff’s personal email addresses go into the staff members’ inbox folder, whereas they go into the junk mail folder in staff members’ nhs.net email accounts.

For staff who choose to use their nhs.net email address and find that the emails from Infinity Health go into your nhs.net junk mail, then this can be remedied by doing the following:

Outlook webmail:

  1. In your webmail Outlook, click on the settings icon (cog) on the tool bar at the top of the screen.
  2. In the drop down list in settings, click on ‘View all Outlook settings’ at the bottom of the dropdown box.
  3. On the left pane, choose Junk email, then Safe senders and domains.
  4. In the box, enter the email address (noreply@infinity.health) and select the Add button.
  5. Then click Save.

Outlook application: 

  1. Open the Junk Mail mailbox
  2. Select the email and right click
  3. From the dropdown list go to ‘Junk’
  4. From the dropdown list in ‘Junk’, click ‘Not Junk’
  5. A box appears ‘Mark. As Not Junk’, with a message (with ticked box): ‘Always trust email from nonreply@infinity.health.
  6. Click OK.

To note: 

For any system queries please contact:

Preparation for using the self testing kit

What training do I need to perform these tests?

Follow the instructions in the Lateral flow device guide[pdf] 541KB

This has been developed nationally by NHS - it includes instructions on how to undertake the test, how to interpret the results, disposal of waste, and storage.

It is important to read through these carefully before you attempt to perform any test.

The instruction video should be watched before you attempt to perform any test.

The manufacturer’s instructions are included in the test kit boxes and are detailed and very technical. These instructions should NOT be followed as NHS staff will use the test in a slightly different way. Once you’ve read the documents and watched the video you should be ready and able to perform the test.

Direct observation of staff as a part of training is not required but will be available if needed. Please contact the site leads if any assistance is required.

For staff who have dexterity or other issues they are concerned about, then support with swabbing on site at work can be provided on request. Please discuss this with your line manager if required.

How often should I test myself? 

You should test yourself twice weekly every three to four days to fit with shift patterns and leave requirements; for example, Wednesday and Sunday, or Monday and Thursday. 

The optimal time is in the few hours before attending work. 

You do not need to take the test when on leave, on non-work days or when working from home, but do perform the test on the first day you return to work, before you come into work. 

One test box contains 25 cartridges, which enables testing for a period of 12 weeks. 

What time of day should I be doing the test?

This depends on the shift you are working. The optimal time to perform the test is within a few hours before you come into work to maximise the chances of detecting a recently acquired infection before arriving at work. However, if testing in the morning is not possible it is acceptable to test the night before your shift starts.

The hands-on time of the LFD test is a few minutes only. If you give yourself an extra ten minutes pre-work preparation time than usual, you should be able to complete, read and report the test before you leave home.

From a hospital infection prevention control perspective, this will minimise the risk of you starting your shift when infectious, hence testing a few hours before a shift is best from a hospital infection prevention control perspective.

Am I allowed to test myself the night before my shift instead of in the morning?

Testing yourself in the morning or just before your shift is preferred to maximise the chances of detecting a recently acquired infection before arriving at work. However, if testing in the morning is not possible it is acceptable to test the night before your shift starts.

Should I use the test if I have any symptoms of Covid-19?

No. You should not use this test if you have developed Covid-19 suspect symptoms, since the LFD may give a false-negative result and hence provide a false re-assurance. 

The test is intended for asymptomatic patient-facing staff only. 

If you have any Covid-19 suspect symptoms, report to your line manager and the employee wellbeing service (OH) to request a PCR or email the team if you don't have access to this intranet page.

Why is the test insert that was in the box different to the instructions given to me by the trust and NHS?

The box contains a technical document from the manufacturers. Feel free to read this, but it contains lots of information that may not be very helpful. The instructions in this ‘test insert’ may also differ slightly from the instructions we have given on how to perform the test. 

It is very important you follow the Lateral flow device guide[pdf] 541KB.

What should be in the box when I open it?

Each box/testing kit will contain the following:

  • 25 foil pouches containing the test strip (and a desiccant)
  • 2 vials of 6mls buffer solution
  • 25 extraction tubes and 25 tube caps
  • 25 sterilised swabs for nasal sample collection

Other items not included in the box that you will need to have with you when you do your test: 

  • A small container (for example a small cup) in which to place the extraction tube so it doesn’t fall or get knocked over and spill the contents
  • A timing device (for example your phone stop watch or kitchen timer) to make sure the test runs for its 30 minutes and no more

Performing the Covid-19 self swabbing test

What should be in the box when I open it?

Each box/testing kit will contain the following:

  • 25 foil pouches containing the test strip (and a desiccant)
  • 2 vials of 6mls buffer solution
  • 25 extraction tubes and 25 tube caps
  • 25 sterilised swabs for nasal sample collection

Other items not included in the box that you will need to have with you when you do your test: 

  • A small container (for example a small cup) in which to place the extraction tube so it doesn’t fall or get knocked over and spill the contents
  • A timing device (for example your phone stop watch or kitchen timer) to make sure the test runs for its 30 minutes and no more

How do I perform the LFD test?

You need to swab the inside of both nostrils, but not the throat. 

Please ensure that you roll the swab ten times along the inside of each nostril, to ensure a good quality sample as described in the Lateral flow device guide[pdf] 541KB

Before performing the test for the first time, carefully read the Lateral flow device guide[pdf] 541KB, since it contains useful tips, such as using an egg cup to keep the extraction tube upright. 

It is really important that you follow all the steps in the correct order as described in the guides.

It is also important that you read the result at 30 minutes after start of the incubation (use a timer or stopwatch). 

Once you have performed the test a few times, you will find that it only takes a few minutes of hands-on time to perform the test, and that it is not difficult to do.

What happens if I read the test result too early or too late?

It is important that you read the result at 30 minutes after start of the incubation.

If you read the result too soon – before 30 minutes are up, this may give a false negative result. 

If you read the result after 30 minutes, a positive signal that has appeared cannot be trusted as it may be a false positive. If it’s only a few minutes this shouldn’t make a difference, but if you’ve left it a long time then you should therefore repeat the test with a new swab and test cartridge, following all the steps in the correct order as described in the Lateral flow device guide[pdf] 541KB, and ensuring that you read the result at 30 minutes. 

What to do with your results

Upload your results - whatever the outcome

Most staff are now registered on the Infinity Health website and are able to upload their test results to the website. Staff can still upload their test results onto the Infinity Health website when using lateral flow test kits sourced from either the gov.uk website or their local pharmacy, and we would ask that staff continue to do so.

Any member of staff not yet registered on the Infinity Health website can be registered by contacting Arthur Jones at arthur.jones@nhs.net.

In order to upload your results you need to use the ‘Submit test result’ and ‘manage settings’ links you've received in your email reminders. 

The links are valid for 72 hours and can only be used by the recipient to update details associated with the email address it was sent to. 

You will be required to enter:

  • the test strip number 
  • the date of the test 
  • the test result 

What do I do if I have a positive result on the LFD test? 

Do not panic. 

Finding a positive result is not uncommon during a wave of Covid-19 in the community, and is the reason that you perform the test. 

  • If you see a line in both the “C” (control) and the “T” (test) area of the LFD, then the test is positive. This is the case even if the line on the “T” (test) area of the LFD is quite faint, so long as you read the test result at 30 minutes and don’t leave it longer before reading.
  • Report the result to your line manager.
  • Record and upload your positive result on the self-testing screen.
  • You, and your household, will need to begin self-isolation as per PHE guidelines.
  • Contact the employee wellbeing service to arrange a confirmation PCR test or email the team if you do not have access to the intranet. EWS will arrange with you how best to get a PCR swab done to confirm the positive result – this may be using a drive through service in the trust, or we may be able to have a swab couriered out to you.
  • If the positive LFD result is confirmed with a positive PCR test, you and your household should complete self-isolation as per PHE guidelines.
  • If the PCR result is negative, and you (and your household members) are asymptomatic you (and your household) may stop self-isolation and return to work as normal after informing your line manager.
  • If you test positive with a PCR test you should not undergo any further lateral flow device testing for a period of 90 days. Please see the question below to find out what you should do with your kit.

What do I do if I get a positive lateral flow test[docx] 215KB

What should I do with my lateral flow test kit if I test positive for Covid-19? 

If you get a positive lateral flow test which is confirmed by a positive PCR test you should keep your kit (not dispose of it) for later use. You may then restart regular testing using the same kit provided the expiry date on the box has not been reached and they have been stored correctly.

Kits should not be given away or used on friends/family and they should be stored out of direct sunlight and sources of heat.

What do I do if I am unsure if I have a positive result on an LFD? 

If you see a clear line in the “C” (control) area and a faint line at the “T” (test) area, and you have read it well after the 30 minutes are up, then this may indicate a false positive result.

You should then repeat the test with a new swab and a new cartridge, following all the steps in the correct order as described in the lateral flow device guide [pdf] 541KB, and ensure that you read the result at exactly 30 minutes. 

If the repeat test is negative (= a line in the “C” (control) area only), then record the result as negative. 

If the repeat test is displaying a clear line in the “C” (control) area and again a faint line at the “T” (test) area at 30 minutes, then record the result as positive and follow steps above as per question 19.

If I get a positive result on an LFD, do I need to self-isolate?

Yes, you need to start self-isolation immediately as per government guidelines

If I get a positive result on an LFD what about the rest of my household?

If you get a positive result on an LFD your entire household will also need to start self-isolation as per government guidelines.

What happens if my PCR swab result comes back negative after a positive LFD test?

This is very unlikely, almost all positive LFD results are confirmed on PCR, a very small minority do not confirm. If you do get a negative result on PCR however, you and your entire household can stop self-isolating immediately, provided no one is symptomatic

You may also return to work immediately. 

What do I do if my LFD test result is negative?

Upload your negative result as outlined above.

So long as you are asymptomatic, continue as normal.

Please remember you still need to follow PPE guidelines at work and during your travel to and from work if your lateral flow test is negative or invalid. The lateral flow test has a lower sensitivity compared to PCR and means some positive cases will be missed with this test. It is therefore vitally important that staff still follow all the trust PPE guidelines.

What do I do if my LFD test result is negative, but I have coronavirus symptoms?

You should not use this LFD test if you have developed Covid-19 suspect symptoms, since the LFD may give a false-negative result and hence provide a false re-assurance. The test is intended for asymptomatic staff only. If you have symptoms of Covid-19 please contact EWS for a PCR test.

If you have performed an LFD test with symptoms please upload the result anyway.

If you have coronavirus symptoms, please self-isolate and contact the employee wellbeing service to arrange the more sensitive and specific SARS-Cov-2 PCR test on a virus nose-throat swab. If you do not have access to the Barts Health intranet, email the team.

You must then inform your line manager. 

What do I do if my LFD test result is invalid?

  • If you do not see a line in the “C” (control) areas then the test is invalid. This is irrespective of whether there is a line or not in the “T” (test) area of the LFD. If the control has not worked then the test result is not valid.
  • Record and upload your invalid result on the self-testing screen as outlined above.
  • Repeat the test with a new test cartridge from the same kit. If you do not have enough time to do a repeat test before work, delay the repeat test until the following work day.
  • Before repeating the test, read the lateral flow device guide [pdf] 541KB  carefully and watch the instruction video again to ensure you are following the correct procedure.
  • You should report the invalid results to your line manager who will be aware you haven’t had a negative test that day.
  • If you are asymptomatic then attend work as normal. If you are symptomatic, follow trust guidelines for symptomatic reporting and testing.
  • Your line manager should consider observing you performing the test to check correct technique.

Please remember you still need to follow PPE guidelines at work and during your travel to and from work if your lateral flow test is negative or invalid. The lateral flow test has a lower sensitivity compared to PCR and means some positive cases will be missed with this test. It is therefore vitally important that staff still follow all the trust PPE guidelines.

When you shouldn't use the lateral flow test

Should I use the test if I have any symptoms of Covid-19?

No. You should not use this test if you have developed Covid-19 suspect symptoms, since the LFD may give a false-negative result and hence provide a false re-assurance. 

The test is intended for asymptomatic patient-facing staff only. 

If you have any Covid-19 suspect symptoms, report to your line manager and the employee wellbeing service to request a PCR or email the team if you do not have access to the Barts Health intranet.

What do I do if my LFD test result is negative, but I have coronavirus symptoms?

You should not use this LFD test if you have developed Covid-19 suspect symptoms, since the LFD may give a false-negative result and hence provide a false re-assurance. The test is intended for asymptomatic staff only. 

As you have done the test, record your negative result as outlined above.

The LFD test may be false negative, as we know it is not as sensitive as the PCR. 

If you have coronavirus symptoms, please self-isolate and contact the employee wellbeing service to arrange the more sensitive and specific SARS-Cov-2 PCR test on a virus nose-throat swab. If you do not have access to the Barts Health intranet, email the team.

You must then inform your line manager. 

Can I use the LFD test to test my family members or friends? 

No. Under no circumstances should you use the LFDs to test family members or friends. These kits are provided by the NHS for testing of trust staff only. You are only provided with one testing kit and this needs to last you for the 3 month period. 

Staff and family members who have symptoms such as high fever, persistent cough or loss of smell/taste, should access the more sensitive and specific virus nose-throat swab PCR test in the normal way. If anyone in your household does receive a positive PCR or LFD test then you must begin self-isolation, and inform your line manager and EWS.

Should I perform this test if I have had a positive COVID-19 PCR result in the last 3 months? 

No. You should not do the LFD test if you have had a positive Covid-19 PCR in the last 90 days. The LFD may give a false positive result if you have recently had Covid-19.

If however you tested PCR positive for COVID-19 more than 90 days ago, then you are encouraged to be involved in the testing, since re-infection after 3 months has been described, although sporadically.

When should I NOT perform the LFD test?

  • You should not perform the test on non-work days, when on leave or if working from home.
  • If you have had a positive Covid-19 PCR in the previous 90 days, you should not perform the LFD as it may give false positive result. 
  • You should not use testing kits on anyone else including friends and family
  • If you have any Covid-19 symptoms, you should NOT perform the LFD test.

All other questions

What happens if I miss a test?

Don’t worry, you can perform your next test before your next work shift. Report your missed test to your line manager. 

What happens if I don’t want to keep testing myself regularly?

Testing is not mandatory, but as a patient-facing staff member you are encouraged to be involved in the testing during a period of increased incidence of Covid-19, to benefit your colleagues and patients. 

If you want to discontinue regular testing please discuss this with your line manager so we can understand the reasons why you no longer want to undergo regular testing. 

Are there any safety concerns in doing the LFD test? 

There are no safety concerns if the test is performed according to Flow chart for using the lateral flow test[docx] 62KB. The extraction fluid may be harmful if swallowed. If you happen to swallow it accidentally, seek medical assistance. Always keep the box out of reach of children or pets.

Should I perform this test if I have had a positive Covid-19 antibody result in the last 12 months? 

At the time of writing this question it was not known if a positive Covid-19 antibody test result represents immunity to infection, and if so for how long. Therefore you are still encouraged to be involved in the LFD testing progamme.

Should I continue to do the LFD test if I have had a Covid-19 vaccine? 

If you have received either your first or both doses of the Covid-19 vaccine you are encouraged to be involved in regular asymptomatic testing. Although vaccination reduces risk of infection and reduces transmission, it does not eliminate either. Infections are still seen, especially asymptomatic infection. It is also unclear how long the vaccine provides protection for and so regular screening remains an important part of keeping yourself, your patients, and your colleagues safe.

When will NHS Test and Trace be informed of my result? 

NHS Test and Trace are only informed of positive results at the point the confirmatory SARS-CoV-2 PCR test result is known, and only if this result is positive. The positive PCR test result will, as normal, be referred by the laboratory systems to NHS Test and Trace.

Do I still need to follow PPE guidelines at work and during my travel to and from work if I test negative?

YES.

The test has an overall sensitivity of 76.8% for all PCR positive individuals. This means some positive cases will be missed with this test and it is therefore vitally important that staff still follow all the infection control and PPE guidelines.