Guidance

High consequence infectious diseases (HCID)

Guidance and information about high consequence infectious diseases and their management in England.

From:
UK Health Security Agency
Published
22 October 2018
Last updated
15 January 2026 — See all updates

Definition ofHCID

In the UK, a high consequence infectious disease (HCID) is defined according to the following criteria:

Classification ofHCIDs

HCIDs are further divided into contact and airborne groups:

List of high consequence infectious diseases

A list of HCIDs has been agreed by the UK 4 nations public health agencies, with advisory committee input as required.

ContactHCIDs

AirborneHCIDs

Note 1: Human-to-human transmission has not been described to date for avian influenza A(H5N6). Human to human transmission has been described for avian influenza A(H5N1), although this was not apparent until more than 30 human cases had been reported. Both A(H5N6) and A(H5N1) often cause severe illness and fatalities. Therefore, A(H5N6) has been included in the airborne HCID list despite not meeting all of the HCID criteria.

Note 2: No cases reported since 2004, but SARS remains a notifiable disease under the International Health Regulations (2005), hence its inclusion here.

The list of HCIDs will be kept under review and updated by the UK 4 nations public health agencies, with advisory committee input as required, if new HCIDs emerge that are of relevance to the UK.

Status of COVID-19

As of 19 March 2020, COVID-19 is no longer considered to be anHCID in the UK. There are many diseases which can cause serious illness which are not classified asHCIDs.

The 4 nations public healthHCID group made an interim recommendation in January 2020 to classify COVID-19 as anHCID. This was based on consideration of the UKHCID criteria about the virus and the disease with information available during the early stages of the outbreak. Now that more is known about COVID-19, the public health bodies in the UK have reviewed the most up to date information about COVID-19 against the UKHCID criteria. They have determined that several features have now changed; in particular, more information is available about mortality rates (low overall), and there is now greater clinical awareness and a specific and sensitive laboratory test, the availability of which continues to increase.

The Advisory Committee on Dangerous Pathogens (ACDP) is also of the opinion that COVID-19 should no longer be classified as anHCID.

The World Health Organization (WHO) continues to consider COVID-19 as a Public Health Emergency of International Concern (PHEIC), therefore the need to have a national, coordinated response remains and this is being met by thegovernment’s COVID-19 response.

Cases of COVID-19 are no longer managed byHCID treatment centres only. Healthcare workers managing possible and confirmed cases should follow theNational infection prevention and control manual for England (or the equivalent devolved administration infection prevention and control manuals), which includes instructions about different personal protective equipment (PPE) ensembles that are appropriate for different clinical scenarios.

Status of mpox

The virus that causes mpox (MPXV) is currently divided into 2 main genetic groups (clades I and II), which subdivide into multiple lineages.

In June 2022, theACDP recommended that the strain of the virus implicated in community transmission within the UK since mid-2022 (clade IIb, B.1 lineage) should no longer be classified as anHCID. In January 2023, theACDP made an additional recommendation that all of clade II MPXV should no longer be classified as anHCID. At this time,ACDP recommended that clade I MPXV (formerly known as Central African or Congo basin clade) should remain anHCID. The 4 nations public health agencies reviewed this advice and agreed with the view ofACDP.

In February 2025, the evidence base for clade I MPXV was reviewed in the context of theHCID criteria, following sustained community transmission of the virus in several African Region countries, and travel-associated cases reported globally, including in the UK. The evidence was discussed by an External Assessment Group (comprising representatives from the 4 nations public health agencies andHCID network) and presented to theACDP. In February 2025, theACDP recommended derogation of all clade I MPXV, which was accepted by the 4 nations Chief Medical Officers, meaning that mpox is no longer anHCID.

HCIDs in the UK

HCIDs are rare in the UK. When cases do occur, they tend to be sporadic and are typically associated with recent travel to an area where the infection is known to be endemic or where an outbreak is occurring. None of theHCIDs listed above are endemic in the UK, and the known animal reservoirs are not found in the UK.

The UK has experience of managing confirmed cases of Lassa fever,EBOD,CCHF,MERS and avian influenza A(H5N1). The majority of these patients acquired their infections overseas, but secondary transmission ofMERS has occurred in the UK.

Avian influenza A(H5N1) has caused outbreaks in wild birds and captive birds in the UK. In January 2022, the UK Health Security Agency (UKHSA) reportedthe first human case of avian influenza A(H5N1) in the UK. Animal-to-human transmission of avian influenza is very rare and the risk to human health is kept under frequent review. The epidemiology and genomics of A(H5N1) virus and human health risk is actively monitored byUKHSA, in collaboration with international partners.

HCID risks by country

For health professionals wishing to determine theHCID risk in any particular country, an A to Z list of countries and their respectiveHCID risk is available.

SeeHCID country risks.

Global HCID events under monitoring

UKHSA’s epidemic intelligence activities monitor potential emerging infectious disease threats, including global HCID events. Summaries of selected events can be seen onoutbreaks under monitoring.

Infection prevention and control in healthcare settings

Specific infection prevention and control (IPC) measures are required for suspected and confirmedHCID cases, in all healthcare settings (specialist and non-specialist).

IPC guidance appropriate for suspected and confirmed cases of Lassa fever, EBOD, CCHF, MARD, Lujo virus disease, Argentinian haemorrhagic fever caused by Junin virus, Machupo virus infection, Chapare virus infection, andSFTS, is available in the ACDP guidance.

IPC guidance, includingPPE, forHCIDs can be found in theNational infection prevention and control manual (NIPCM).

Specialist advice for healthcare professionals

TheImported Fever Service (IFS) provides 24-hour, 7-days a week telephone access to expert clinical and microbiological advice. Hospital doctors across the UK can contact theIFS after discussion with the local microbiology, virology or infectious disease consultant.

Hospital management of confirmedHCID cases

Once anHCID has been confirmed by appropriate laboratory testing, cases in England should be offered admission and transfer to a designatedHCID Treatment Centre. Occasionally, highly probable cases may be moved to anHCID Treatment Centre before laboratory results are available.

ContactHCIDs

There are 2 principal ContactHCID Treatment Centres for adults in England, serving the whole of the UK:

Further support for managing additional confirmed adult contactHCID cases can be provided by the University Hospitals of Liverpool Group (Royal Site) Royal Liverpool Hospital and the Royal Hallamshire Hospital, Sheffield, if necessary.

There are 2 ContactHCID Treatment Centres for children in England:

AirborneHCIDs

There are 7 adult and 5 paediatric AirborneHCID Treatment Centres in England:

During larger airborneHCID outbreaks, confirmed adult cases may also receive care in specialist regional infectious disease centres, if this has been agreed at a national level.

Travel health advice forHCIDs

The National Travel Health Network and Centre (NaTHNaC) provides travel health information about a number ofHCIDs, for healthcare professionals and travellers. Advice can be accessed via theTravel Health Pro website

Updates to this page

Published 22 October 2018
Last updated 15 January 2026show all updates

  1. Chapare virus added.

  2. Case transfer arrangements information removed.

  3. Updated the reports section. The high consequence infectious diseases monthly summaries were discontinued in March 2025 and have been replaced with the outbreaks under monitoring page.

  4. Reorder in alphabetical order for the guidance list.Added in Argentine haemorrhagic fever and Lujo virus guidance pages. Updated abbreivations for Ebola virus disease (EVD) and Marburg virus disease (MARD).

  5. Updated the "Hospital management of confirmed HCID cases" section.

  6. Updated to reflect HCID derogation of clade I mpox.

  7. Updated in line with the HCID derogation of Clade II mpox (monkeypox). Added information about the first human case of avian influenza A(H5N1) reported in the UK.

  8. Updated to reflect changes to the HCID status of monkeypox.

  9. Updated to reflect the change in monkeypox clade nomenclature.

  10. Updated to reflect clade of monkeypox virus involved in community transmission in the UK being declassified as an HCID.

  11. Added link to Andes hantavirus guidance.

  12. Added link to page on severe fever with thrombocytopaenia syndrome (SFTS).

  13. Updated 'Status of COVID-19' section.

  14. Added Sheffield Teaching Hospitals NHS Foundation Trust to the list of airborne HCID treatment centres in England.

  15. Added explanation of the removal of COVID-19 from the list of HCIDs in the UK.

  16. Added Wuhan novel coronavirus

  17. Amended the definitions for HCID.

  18. Added explanation for inclusion of avian influenza H5N6 as an HCID.

  19. Added link to information on HCID risks by country.

  20. First published.

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