We use some essential cookies to make this website work.
We’d like to set additional cookies to understand how you use GOV.UK, remember your settings and improve government services.
We also use cookies set by other sites to help us deliver content from their services.
You can change your cookie settings at any time.
Departments, agencies and public bodies
News stories, speeches, letters and notices
Detailed guidance, regulations and rules
Reports, analysis and official statistics
Data, Freedom of Information releases and corporate reports
This publication is licensed under the terms of the Open Government Licence v3.0 except where otherwise stated. To view this licence, visit nationalarchives.gov.uk/doc/open-government-licence/version/3 or write to the Information Policy Team, The National Archives, Kew, London TW9 4DU, or email: psi@nationalarchives.gov.uk.
Where we have identified any third party copyright information you will need to obtain permission from the copyright holders concerned.
This publication is available at https://www.gov.uk/government/publications/influenza-like-illness-ili-managing-outbreaks-in-schools/investigation-and-management-of-outbreaks-of-suspected-acute-viral-respiratory-infection-in-schools-guidance-for-health-protection-teams
‘Pupil’ should be read as pupil, student, or child depending on the context.
‘School’ is also used to mean college and nursery.
This document provides guidance for local health protection teams (HPTs) about assessing and managing outbreaks of suspected acute viral respiratory infection (ARI) in schools and colleges including special educational needs. Approaches to response, including recommendations on testing, may have applicability in related settings such as early years/nurseries and school holiday clubs.
Every autumn and winter, seasonal influenza viruses and other respiratory viruses like rhinovirus and respiratory syncytial virus (RSV) cause school outbreaks. Since early 2020, SARS-CoV-2, the novel coronavirus that causes coronavirus disease (COVID-19), has been in circulation within the UK, and has led to cases and outbreaks linked to schools. All these viruses can present with similar symptoms and so it is essential that suspected ARI outbreaks in schools are investigated and managed appropriately.
Central to the approach to this setting, is the communication of key preparedness messages to schools, including awareness of arrangements for reporting of outbreaks to local HPTs, exclusion advice for unwell children (which will vary depending on the respiratory diagnosis), as well as the national childhood immunisation programmes such as that for influenza.
Schools are experienced in management of cases of childhood respiratory viruses. Schools may escalate concerns to HPTs if they have concerns related to:
Epidemiological definitions of cases and outbreaks are primarily used for surveillance purposes and should not be taken as indicating thresholds for HPT referral or public health action.
A key intervention to limit the transmission of flu in schools is to ensure successful delivery of the childhood influenza immunisation programme in eligible year groups. In influenza outbreak situations, antivirals may also be considered for unvaccinated exposed children in clinical risk groups, in line with national guidance, such as that published by the National Institute for Health and Care Excellence (NICE) and the UK Health Security Agency (UKHSA).
The main guidance relating to specific situations which should be read in parallel with this guidance includes UKHSA guidance on health protection in schools and other childcare facilities (for example, for exclusion advice).
Separate considerations will apply for residential educational settings and special schools (see Appendix 1 and Appendix 2).
Seasonal influenza, COVID-19 and other acute respiratory infections may transmit rapidly between children of school age, prompting the occurrence of localised outbreaks within schools. It is important to note that localised influenza outbreaks in school settings may precede circulation of seasonal influenza in the wider population. Co-circulation of multiple viruses is possible in a school or community. Other common viruses causing acute respiratory infection in children include RSV, rhinovirus and parainfluenza.
Symptoms of acute viral respiratory infections (see Definitions) in children are difficult to distinguish between causative agents. Public health virological testing is not routinely undertaken for school outbreaks but may be considered by the consultant in health protection or other senior health protection staff if circumstances suggest utility. For a subset of more complex ARI outbreaks, such as: i) those involving children in clinical risk groups in special schools, or ii) when there is a high attack rate, iii) multiple cohorts are affected, iv) there are reports of hospitalisations or deaths; HPTs should pursue rapid multiplex testing for a range of respiratory viruses (for example, SARS-CoV-2, influenza A, influenza B, and RSV). This will provide useful information for the management of these outbreaks but will also provide important intelligence for surveillance purposes.
Influenza and COVID-19 vaccines are offered to many children by the NHS. Schools may have a direct role in facilitating delivery, including promotion, of influenza vaccination for their pupils. The national flu immunisation programme letter includes detailed information on plans for the forthcoming season. The childhood influenza vaccination programme which has undergone a phased introduction since 2013, is now an integral part of the national seasonal influenza vaccination programme.
As in previous influenza seasons, seasonal influenza vaccination is also available for individuals aged 6 months and older in clinical risk groups, as specified in the Green Book and the national flu immunisation programme letter. National recommendations on childhood COVID-19 vaccination are summarised in the Green Book.
HPTs should be aware that when they receive a report of acute respiratory infection in school-age children during the influenza season, some of those in the affected school may have already received seasonal influenza vaccination.
Achieving high uptake of the seasonal childhood influenza vaccination programme in schools is a key component of influenza preparedness. The aim is to reduce the public health impact of flu by:
Research by the UK Health Security Agency (UKHSA) suggests that co-infection of both flu and COVID-19 is associated with a greater risk of more severe illness and death in adults (1). Therefore, during the winter season, influenza vaccination will be even more important in reducing related morbidity and mortality.
Many schools have existing arrangements to identify acute respiratory infection among pupils, such as monitoring of related absences. Schools should be aware of the most up to date information on local mechanisms for seeking advice in relation to observed increases of acute respiratory infection, including risk assessment of potential outbreak situations. Response arrangements will continue to be reviewed during the COVID-19 pandemic. However, in most localities this will involve the local health protection team (HPT).
Schools may also be aware of individual pupils who are in clinical risk groups (as part of the schools’ health and welfare arrangements), and this information will be important for the rapid provision of information to families of these children during an outbreak.
It is useful for schools to be signposted to guidance on health protection in schools and other childcare facilities, including exclusion advice, prior to the beginning of the influenza season.
The term acute respiratory infection (ARI) includes presentations both of influenza-like illness (ILI) and other acute viral respiratory infections (AVRI). Other causal pathogens can include SARS-CoV-2, RSV, adenovirus, rhinovirus, parainfluenza and human metapneumovirus (hMPV).
See Appendix 1 and Appendix 2 for additional considerations in residential educational settings and special schools.
Epidemiological definitions of cases and outbreaks are primarily used for surveillance purposes and should not be taken as indicating thresholds for HPT referral or public health action.
Symptoms of influenza, COVID-19 and other common respiratory infections can include:
Influenza-like illness (ILI) is defined in an education or early years setting as:
It is acknowledged that influenza may vary in presentation in children, such as without fever or with diarrhoea, among others. These would not meet the ILI definition above, therefore if there is a suspicion of influenza in such children with these other clinical presentations, they would only be regarded as a case with a positive laboratory testing result for influenza.
Other symptoms associated with influenza can include malaise (tiredness), headache, myalgia (muscle pain), diarrhoea, nausea/vomiting, sore throat and shortness of breath.
A confirmed case of influenza is an individual with laboratory detection of influenza virus from a respiratory sample (usually a nose or throat swab).
Sudden onset of symptoms and at least one of the following 4 respiratory symptoms:
With no non-infectious cause suspected.
A suspected ARI outbreak in a non-residential school or educational setting is defined as:
Epidemiological evidence of transmission within the school includes both cases having attended the school on at least one of the 7 days before onset in the absence of a known, alternative source of infection (for example, a household member reported to have influenza-like illness).
The epidemiological likelihood of a respiratory outbreak being due to influenza is increased if influenza has been declared to be circulating in the general community and particularly if there is evidence of local influenza transmission. Cases coming to the attention of school authorities and HPTs may not represent all cases as there may be unobserved transmission within school settings.
Epidemiological definitions of cases and outbreaks are primarily used for surveillance purposes and should not be taken as indicating thresholds for HPT referral or public health action.
For residential settings, assement should take into account residential geographies and other mixing patterns.
Two or more laboratory confirmed cases of influenza among individuals (students or staff) with an epidemiological link to the educational setting, arising within a single 7-day period.
Two or more laboratory confirmed cases of the same AVRI pathogen (including any typing or sequencing, if done) among individuals (students or staff) with an epidemiological link to the educational setting, arising within a single 14-day period.
The end of a test-confirmed influenza outbreak is defined as a single 7-day period following symptom onset of the last outbreak case, during which there are no new cases of ILI or confirmed influenza cases within the same school group.
The end of an ARI outbreak where influenza has not been confirmed by laboratory testing is defined as a single 14-day period following symptom onset of the last outbreak case, during which there are no new cases of ARI within the same school group.
Incubation period: The median incubation period of influenza is 2 days (range 1 to 4 days).
Infectious period: For influenza the period of infectiousness (that is communicability) starts with the onset of ILI symptoms and lasts for the duration of symptoms.
Incubation period: The median incubation period of COVID-19 is 5 days (range 1 to 14 days).
Infectious period: The infectious period is from 2 days prior to symptom onset (or 2 days prior to positive test if asymptomatic) and extend for up to 10 days post onset of symptoms (or positive test date if asymptomatic).
All may have similar symptoms to other ARI.
Incubation periods vary between respiratory viruses, but are usually between 12 hours and 5 days, extending up to 8 days for RSV and parainfluenza.
When an ARI outbreak is initially notified to an HPT, the information listed in section 6.1.1 below will be useful to inform a risk assessment. This will help the HPT conduct an assessment of the likelihood of influenza and COVID-19, the severity and extent of the outbreak, and guide control measures. Equivalent local checklists may be deployed. This information should be captured on the HPT’s outbreak or situation record. It is appreciated that schools commonly experience periods when respiratory viruses readily circulate amongst their children and staff, and respond to these within their usual practices. School management are most likely to contact HPTs when they have specific concerns such as high absence rates, severe cases, or setting specific concerns such as as residential or special need.
6.1.1.1 Information about the school or educational setting:
Any sampling that is undertaken to identify the causative organism for an ARI outbreak in a school (other than COVID-19) should be informed by national and local surveillance data.
Routine virological investigation of school ARI outbreaks is not essential for every outbreak but should be considered in:
Laboratory confirmation of influenza in particular is most useful in the inter-seasonal period and early in the influenza season, when national surveillance schemes have not yet confirmed that influenza is circulating widely in the community. During these time periods, other respiratory viruses may be as likely as seasonal influenza to cause ILI presentations and so there is a role for laboratory confirmation to inform the risk assessment and subsequent public health advice for individuals in risk groups who may benefit from antivirals.
When complex ARI school outbreaks arise, the HPT should consider testing symptomatic individuals for a broad range of respiratory viruses including influenza A, influenza B, SARS-CoV-2 and RSV.
When swabbing is indicated HPTs should work with local system partners to arrange multiplex testing through local swabbing arrangements, including NHS and UKHSA laboratories as appropriate to their local context. This will provide useful information for the management of these outbreaks but will also provide important intelligence for surveillance purposes.
Sampling should be undertaken as close as possible to illness onset (and no more than 7 days after onset). Those aged 11 years or less should be swabbed by a parent or guardian, while self-swabbing can be considered for children and young people 12 years and older. When considering multiplex testing, it is particularly useful if swabs can be returned via a central point to the diagnostic laboratory (as per local arrangements) so that transport of samples can be co-ordinated and the timeline for reporting of the overall results can be estimated.
Further advice on testing during outbreaks can be sought from the local public health laboratory in the first instance. Local arrangements should be made with the regional laboratory for rapid turnaround of testing in response to outbreak investigation.
Expert epidemiological advice can be sought from the national flu team, for example, if wider testing is being considered to better understand the epidemiology of the outbreak.
During the winter, there may be simultaneous circulation of multiple pathogens within a single ARI outbreak.
Local HPT risk assessment as above will inform a decision as to whether the situation meets the definition of an outbreak (see section 4. Definitions).
Once an outbreak has been declared, local stakeholders (for example, directors of public health and local authority public health teams) should be informed as per local protocols, and in line with the overall public health risk assessment. Where necessary (for example, complex situations, with large numbers of cases) an outbreak control team (OCT) should be considered.
Consider the need for an OCT if:
Infection prevention and control (IPC) measures (where appropriate) should be implemented according to Health protection in schools and childcare.
Cases with mild symptoms such as a runny nose, sore throat, or slight cough, who are otherwise well, can continue to attend their education setting unless directed otherwise by the HPT. There may be lower thresholds for self-isolation in an ARI outbreak.
Cases who are unwell and have a high temperature should stay at home and avoid contact with other people, where they can. They can go back to school, college or childcare when they no longer have a high temperature and they are well enough to attend.
Symptoms such as cough and anosmia can persist for weeks after the acute infectious episode and should not prevent return to school.
Those testing positive for COVID-19 should follow national guidance on preventing spread to others.
If applicable, the school should ensure effective communication to:
Influenza antiviral treatment may be recommended for certain children during confirmed influenza outbreaks. Any decision to recommend influenza antiviral treatment:
Where influenza antiviral treatment is recommended, the local HPT may advise that:
When the number of children in clinical risk groups is thought to form a relatively small proportion of the school’s pupils and the CMO has not advised that antivirals may be prescribed in primary care, it may be possible for these to be prescribed by a hospital health professional such as a paediatrician. Consider writing a letter to parents or guardians to explain the situation. An alternative would be to telephone the parents directly, if this would expedite access to antivirals within the recommended time periods for starting prophylaxis (36 to 48 hours depending on the individual medicine).
Parents or guardians with an exposed child in a clinical risk group should then contact their specialist clinician looking after their child or be referred to paediatric Accident and Emergency (A&E) department to be considered for antivirals; the local HPT may need to facilitate this according to local processes. This is the preferable approach, as these health professionals will have the relevant medical history for these children.
If antivirals are indicated, the local HPT should discuss procurement with the local NHS commissioner as soon as possible.
The need for antivirals among staff in clinical risk groups should be addressed in a similar way to that outlined for children above.
In a confirmed influenza outbreak, consideration should be given to wider influenza vaccination throughout the educational setting, especially in settings with low uptake of influenza vaccination to date.
The vaccination does not provide post-exposure prophylaxis. Two weeks are required for the immune response to vaccination to develop, and so this is unlikely to prevent secondary and tertiary cases. However, if an influenza outbreak is occurring in a school where flu vaccination has yet to be delivered, consideration may be given as to whether the vaccination session can be brought forward; this may help to prevent further transmission and shorten the duration of the outbreak. Local NHS services may also have catch up clinics that parents could be signposted to if the school vaccination session has been done and their child is not yet vaccinated.
Follow-up of individual outbreaks in schools should be undertaken according to local HPT processes.
Schools should be advised when to call the HPT, especially if there are any features of concern (such as those outlined for calling an OCT, see 6.3 Declaration of outbreak).
It is anticipated that temporary closure of a school for public health reasons is likely to be an infrequent measure for ARI outbreaks. Any enquiry about potential closures on public health grounds should be discussed by the school management team directly with the local UKHSA HPT in the first instance, and school closure on public health grounds should be an OCT decision. Any decision to temporarily close for business continuity reasons, such as staff shortages, is a decision for the school management and local education authority, where applicable. However, it should be made clear to parents, guardians and staff that this decision has not been made on public health grounds.
Outbreak reporting forms are not required for routine surveillance. Probable and confirmed outbreak surveillance data is obtained from HPZone. Information about acute viral ARI outbreaks in schools where the causative agent is identified should, in the first instance, be recorded on HPZone as per routine practice and data captured in the HPZone metrics when possible rather than as free text (see section 6.1.1). These data will then be extracted by the national surveillance team and reported on in the weekly surveillance reports.
1. Stowe and others. ‘Interactions between SARS-CoV-2 and influenza, and the impact of coinfection on disease severity: a test-negative design.’ International Journal of Epidemiology 2021: volume 50, issue 4, pages 1,124 to 1,133
2. Johnson and others. ‘Seroepidemiologic study of pandemic (H1N1) 2009 during outbreak in boarding school, England.’ Emerging Infectious Diseases 2011: volume 17, number 9
3. Chaves and others. ‘Patients hospitalized with laboratory confirmed influenza during the 2010-11 influenza season: exploring disease severity by virus type and subtype.’ The Journal of Infectious Diseases 2013: volume 208, pages 1,305 to 1,314
4. Keren and others. ‘Neurological and neuromuscular disease as a risk factor for respiratory failure in children hospitalized with influenza infection.’ Journal of the American Medical Association 2005: volume 294, number 17
Transmission of respiratory viruses can be rapid in boarding schools and other residential educational settings, with high attack rates (2).
As a closed setting, for these settings:
Special educational needs and disabilities (SEND) include 4 different areas of need, including communicating and interacting; cognition and learning; social, emotional and mental health difficulties and sensory or physical needs.
Many children and young people with special educational needs and disabilities have one or more conditions which place them at increased risk of severe influenza infection, and as such are likely to be members of clinical risk groups. Examples of relevant conditions include, but are not limited to, cerebral palsy, hydrocephalus, neuromuscular diseases (for example, spinal muscular atrophy, Duchenne muscular dystrophy) (3, 4).
Therefore, an influenza outbreak in a special school setting, where a significant proportion of the learners are members of clinical risk groups, has the potential for serious clinical illness.
Rapid public health intervention following a thorough risk assessment, is therefore justified in relation to outbreaks in such settings. Confirmation of the causative organism by rapidly testing recent symptomatic cases for COVID-19, influenza and other respiratory viruses can be useful to inform management. Advice on consideration of antivirals where influenza is strongly suspected or laboratory confirmed can be obtained from the UKHSA Clinical and Public Health Group, as required.
In order to support rapid public health action, when the CMO has advised that seasonal influenza is circulating in the community, local NHS commissioners should determine if central distribution of antiviral treatment or prophylaxis in confirmed influenza outbreaks would be more practicable than individual children’s families contacting their specialist health professionals and paediatric A&E. When flu is not circulating, the local HPT will need to work with NHS commissioners to identify alternative mechanisms for accessing and prescribing antivirals for treatment or prophylaxis in a timely way.
Individual children with special needs, attending other settings (for example, mainstream schools), should receive information as outlined in the control measures section. Centralised prescribing and distribution may not be required, as there may be a smaller number of children in clinical risk groups in these settings.
Version 3.0 was reviewed and updated in 2022 by Conall Watson in consultation with health protection and child public health specialists and the UKHSA Immunisation and Vaccine-preventable Diseases Division Influenza Scientific Advisory Forum.
Fernando Capelastegui provided scientific secretariat support.
Don’t include personal or financial information like your National Insurance number or credit card details.
To help us improve GOV.UK, we’d like to know more about your visit today. We’ll send you a link to a feedback form. It will take only 2 minutes to fill in. Don’t worry we won’t send you spam or share your email address with anyone.