Guidance

SARS-CoV-2 and influenza A+B antigen combo rapid tests for COVID-19 and 2 types of flu during an outbreak of acute respiratory infection in adult social care homes in South East England

Published 4 September 2025

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This publication is available at https://www.gov.uk/government/publications/combined-covid-19-and-flu-tests-use-in-ari-outbreaks-in-adult-social-care-homes-in-south-east-england/sars-cov-2-and-influenza-ab-antigen-combo-rapid-tests-for-covid-19-and-2-types-of-flu-during-an-outbreak-of-acute-respiratory-infection-in-adult-soci

These tests are only available to care homes in the South East Region of England. Care homes in other regions should follow their usual outbreak reporting procedures.

If you are a care home in the South East Region and one or more residents has tested positive for flu, telephone the South East Health Protection Team on 0344 225 3861.

If you are a care home in the South East Region and you think there is a respiratory outbreak but do not have any combo rapid tests, telephone the South East Health Protection Team on 0344 225 3861.

Who this guidance is for

This guidance is only for staff working in adult social care homes in South East England. It explains how to test residents with respiratory symptoms using combo rapid tests in the event of a suspected outbreak. Care homes in other regions should follow their usual outbreak reporting procedures.

Purpose of using combo rapid tests

We know that if actions are taken to control outbreaks quickly, the size and length of the outbreak is reduced. A quicker result will also benefit residents as they can be put on the right treatment pathway straight away. If the outbreak is caused by flu, antivirals can be prescribed quickly when they are more effective.  

Care homes that are using the tests

Combo rapid tests are only being sent to adult social care homes registered by the Care Quality Commission (CQC) across the South East Region of England as part of a service evaluation. Your care home should have received a supply of 5 tests. 

You will already be familiar with NHS COVID-19 lateral flow device (LFD) tests which are used to test symptomatic residents who are eligible for COVID-19 treatments. Combo rapid tests should only be used to test for COVID-19 and flu A and B when an outbreak of acute respiratory infection (ARI) is likely in the care home. 

Table 1. The difference between the 2 types of tests and when these tests should be used

NHS COVID-19 LFD tests SARS-CoV-2 and influenza A+B antigen combo rapid tests
Respiratory infections that are included in the test COVID-19 COVID-19
Flu A
Flu B
When to use the test When residents who are eligible for COVID-19 treatments are showing symptoms of an ARI. If the resident tests positive, arrange an assessment for COVID-19 treatments. This test should only be used when an ARI outbreak is suspected among adult residents in your care home, that is when 2 or more linked residents develop symptoms of a respiratory infection within 5 days of each other. Do not use the tests beyond the expiry date.

What is an acute respiratory infection (ARI)

The UKHSA ARI case definition for use in care homes is acute onset of one or more of the respiratory symptoms listed and a clinician’s judgement that the illness is due to an ARI.

We are particularly concerned with flu and ensuring that residents have fast access to antiviral medication.

Symptoms of influenza-like illness

1. Oral or tympanic (ear) temperature of at least 37.8°C and acute onset of at least one of the following respiratory symptoms:

  • cough (with or without sputum)
  • sore throat
  • coryza (nasal discharge or congestion)
  • dyspnoea (shortness of breath)
  • hoarseness
  • sneezing
  • wheezing

or:

2. an acute deterioration in physical or mental ability without other known cause.

How to identify an ARI outbreak 

An ARI outbreak is when there are 2 or more linked cases of ARI within the same care home within a 5-day period. This means the cases have been in contact with each other and the infection may have spread within the care home.

If 2 or more linked care home residents develop symptoms of a respiratory infection within 5 days of each other, the care home should undertake a risk assessment as soon as possible.

The risk assessment should find out whether the cases are likely to have picked up the infection within the care home and if cases are therefore linked. To find out if the cases are linked, the risk assessment should look at whether:

  • there is a known source of infection
  • there was contact between residents while one or more individuals had suspected or confirmed ARI
  • there is a staff member in common for the resident cases
  • the cases all live in the same area of the home (for example floor or unit) or if they are in separate areas and do not have other links
  • the first identified case started in the care home, for example if the resident was in the care home up to 5 days prior to symptoms or a positive test

Cases would be less likely to be considered linked if:

  • symptoms started more than 5 days apart
  • the residents had no contact with each other in the last 5 days

The combo rapid tests should only be used if this risk assessment shows there is likely to be an outbreak. If they are used for other purposes, or are used by staff, UKHSA will not be able to continue to supply them because combo rapid test stock is limited.

How to be prepared for ARIs

The best way to reduce the spread and harm of ARIs is to combine standard infection prevention and control precautions with flu vaccination for both residents and staff, COVID-19 vaccination for everyone who can have it, and RSV vaccination for those eligible (Your guide to the RSV vaccine for older adults) along with available medical treatments and appropriate outbreak management (see guidance Infection prevention and control (IPC) in adult social care: acute respiratory infection (ARI)).

NHS COVID-19 LFD tests

About NHS COVID-19 LFD tests

NHS COVID-19 LFD tests should be used when residents who are eligible for COVID-19 treatments are showing symptoms of ARI. The test should be taken as soon as possible after they develop symptoms.

There is information available on getting NHS COVID-19 LFD tests in the infection prevention and control guidance for managing acute respiratory infections in adult social care, section How to access tests for people eligible for COVID-19 treatments in a residential care setting. Tests for this purpose are supplied by the NHS and should be accessed from a participating local pharmacy. If you have difficulty getting test kits, contact your local integrated care board (ICB). Providers should ensure there are at least 3 tests available for each resident who is eligible for COVID-19 treatments so they can be tested for 3 days in a row if they develop symptoms of ARI.

A list of those who are eligible for COVID-19 treatments can be found on the NHS page for COVID-19 treatments and in the NICE guidance on COVID-19 treatments. Seek medical advice if necessary.

If a resident who is eligible for COVID-19 treatments gets a positive test result on the NHS COVID-19 LFD test, you should organise an assessment for COVID-19 treatments for them. If in doubt, contact your local integrated care board who can help you with this. See NHS guidance on COVID-19 treatments for more information.

SARS-CoV-2 and influenza A+B antigen combo rapid tests

About combo rapid tests

Combo rapid tests look for COVID-19, flu A and flu B in one test. These tests should only be used to test adult residents for COVID-19, flu A and flu B when an ARI outbreak is suspected among care home residents, that is when 2 or more linked care home residents develop symptoms of an ARI within 5 days of each other. 

Combo rapid tests should have been sent to your care home. If you have not received your test kits and have an active outbreak, telephone the South East Health Protection Team on 0344 225 3861.

Stock of combo rapid tests is limited for the duration of this service evaluation and therefore must only be used to test residents if an outbreak is suspected. If these tests are used for other purposes, there will not be enough tests for suspected outbreaks and the service evaluation will finish early. Care homes have been given 5 combo rapid tests to use when there is an outbreak. Do not use the tests beyond the expiry date.

Testing residents during a suspected outbreak of ARI

To use the test, follow the information provided on the back of the box as well as the instructions inside the test kit. The test is taken in the same way as the NHS COVID-19 LFD tests and involves a nasal swab. If you have a suspected outbreak of ARI, test up to 5 of your residents who most recently developed symptoms using a combo rapid test. There is no need to test further residents as the first 5 results will tell you if COVID-19 or flu are causing the outbreak. There are other causes of respiratory symptoms that are not tested for.

Testing residents who are eligible for  COVID-19 treatments  

If you have an ARI outbreak that involves residents who are eligible for COVID-19 treatments as well as those who aren’t, you should use the combo rapid tests to test up to 5 residents who most recently developed symptoms. After you have used the 5 combo rapid tests, any residents who go on to develop respiratory symptoms and who are eligible for COVID-19 treatments should be tested using NHS COVID-19 LFD tests.

What to do with combo rapid test results

Suspected outbreak with all negative combo rapid test results

If all residents who have been tested with a combo rapid test have tested negative for COVID-19, flu A and flu B, you should:

Outbreak where one or more residents test positive for COVID-19 on combo rapid test

If one or more of the residents tested using the combo rapid tests gets a positive result for COVID-19, you should:

Outbreak where one or more residents test positive for flu A or flu B on combo rapid test

If one or more of the residents tested using the combo rapid tests gets a positive result for flu A or flu B, you should:

  • contact the South East Health Protection Team by telephone on 0344 225 3861 to discuss antiviral medication for flu – antiviral medication for treatment and prevention of flu works best when people start them within 2 days of becoming unwell or being in close contact with a person with flu
  • follow the If a service user tests positive for acute respiratory infection guidance and implement outbreak control measures
  • support staff with symptoms to stay away from work until they no longer have a fever (if they had one) and feel well enough to work in line with Support symptomatic staff to stay away from work guidance
  • check residents for flu symptoms (for example fever, cough) – if 2 or more residents have tested positive for flu A or flu B, this confirms a flu outbreak (any further residents who develop symptoms should be assessed by their healthcare provider to see if they need treatment-dose antiviral medication – do not use further rapid combo tests, as the cause of the outbreak has already been confirmed)
  • report your combo rapid results at the same time even if the test results are negative or void – once you have reported your test results, your care home will automatically receive another 5 tests in about one week

Outbreak where residents have tested positive for both COVID-19 and flu on combo rapid tests

If one or more residents have tested positive for COVID-19 and one or more residents have tested positive for flu A or flu B, or one resident has tested positive for both COVID-19 and flu A or flu B, you should:

  • contact the South East Health Protection Team by telephone on 0344 225 3861 to discuss antiviral medication for flu – antiviral medication for treatment and prevention of flu works best when people start them within 2 days of becoming unwell or being in close contact with a person with flu
  • follow the If a service user tests positive for acute respiratory infection guidance and implement outbreak control measures
  • support staff with symptoms to stay away from work until they no longer have a fever (if they had one) and feel well enough to work in line with Support symptomatic staff to stay away from work guidance
  • check other residents for flu symptoms and COVID-19 symptoms (for example fever and cough) – residents can be changed to treatment dose flu antivirals and/or started on COVID medications if eligible (if eligible for COVID-19 treatments, they should be tested using an NHS COVID LFD test – treatment for flu and COVID should be discussed with the healthcare provider for each resident)
  • report your combo rapid test results at the same time even if the test results are negative or void – once you have reported your test results, your care home will automatically receive another 5 tests in about one week

Preventative treatment for flu during an outbreak

If you have a confirmed flu outbreak, UKHSA recommends prompt use of antiviral medication for treatment of residents with flu and preventative treatment for residents who may have been exposed or be at risk of being exposed to flu. 

If a resident with flu has been in a shared area while they had symptoms, then a distance of 2 metres from that individual for 15 minutes or more can be used as a guide to identify exposed people for a risk assessment for antiviral preventative treatment.

Antiviral preventative treatment is most effective if it is started within 48 hours of being in most recent contact with a resident with flu but may be considered after this time following a risk assessment by the health protection team.

When combo rapid tests can be used again

Outbreak measures can stop 5 days after symptoms started in the resident who became unwell most recently. If more of your residents become unwell with respiratory symptoms after this time, and you think there is another outbreak because the residents with symptoms are linked, you can use the combo rapid tests to test again.

You may have had an outbreak on one unit or separate area of your care home. If you now think you have an outbreak in another area of your home, you can use your next set of combo rapid tests if the residents and staff across these two areas do not mix with each other and the infection is not likely to have spread from one area of your home to the other area.    

Resources

GOV.UK website

NHS

National Institute for Health and Care Excellent (NICE)

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