Update on High Consequence Infectious Disease (HCID) Status of mpox

Classification: Official
Publication reference: PRN00070_i


  • Integrated care board (ICB) chief executives
  • ICB medical directors
  • All trust chief executives
  • All trust medical directors


  • All Local Government Chief Executives
  • NHS England Regional Directors
  • NHS England Regional Director of Commissioning
  • NHS England Regional Heads of EPRR
  • Local Authority Directors of Public Health

Update on High Consequence Infectious Disease (HCID) Status of mpox

Dear colleague,

The World Health Organisation has announced that monkeypox is to be renamed mpox to help tackle discrimination and stigma.

In July 2022, the public health agencies of the four nations of the UK agreed that the specific outbreak clade of mpox in the UK (clade IIb with lineage B.1) would no longer be designated as a High Consequence Infectious Disease (HCID). This followed advice from the Advisory Committee on Dangerous Pathogens (ACDP) who noted that the vast majority of UK cases had not been severe, and that a safe and effective vaccine was available and being deployed. At the time, the ACDP recommended that all cases outside of the specific outbreak clade should continue to be managed as HCIDs.

Following the receipt of further advice, the ACDP has now decided that all cases in clade II (including those with non-B.1 lineage and which are associated with travel to West Africa) no longer need to be managed as HCIDs. The is because of the relatively benign clinical phenotype of the currently circulating lineage B.1 within clade IIb, along with firm evidence of effectiveness of available vaccines, access to rapid diagnostic testing, heightened clinical awareness of this infection, and access to safe therapies with experimental evidence of efficacy. Any cases associated with clade I (previously known as the Central Africa clade) MUST still be managed as HCIDs. There have been no confirmed cases in this clade in the UK.

More information about the derogation can be found here: High consequence infectious diseases (HCID) – GOV.UK (www.gov.uk). Details of the HCID status of mpox can be found here: HCID status of mpox (monkeypox) – GOV.UK (www.gov.uk)

Infection prevention and control (IPC) Recommendations are outlined in the Four Nations Principles document and they have made no changes to PPE (Principles for monkeypox control in the UK: 4 nations consensus statement – GOV.UK (www.gov.uk)) or relevant national IPC guidance (NHS England » National infection prevention and control).

Transport of waste from mpox virus

Earlier in 2022, the UK Government countersigned a multilateral agreement, initiated by Germany so that only the cultures form of mpox is classified as Category A (dangerous goods), and that patient samples, infected material etc, will be classified as Category B (as per Clinical Waste and Covid-19 for example). This change came into effect on 5 July 2022.

Classification of mpox virus (Germany) | UNECE

Management of confirmed cases

Whilst the current outbreak (clade IIb with B.1 lineage AND those cases with clade II non-B.1 lineage, i.e. those associated with travel to West Africa), are no longer designated as HCIDs – and there is no requirement for an automatic admission to an HCID Centre – there are a small number of individuals who are significantly impacted by the infection, for example, those with complications such as secondary bacterial infection, sepsis, etc or corneal involvement. Therefore, admitted individuals who require expert care should be managed in either an HCID Centre or a Specialist Regional Infectious Disease Centre (SRIDC).

Other affected individuals, for example those who have severe, refractory pain from lesions or whose lesions are associated with constipation, urinary retention, or an inability to swallow can be treated in an SRIDC or in a local ID unit or in a non-specialised, negative pressure room with 24/7 support from the local SRIDC or an HCID Centre. These facilities should also be used for individuals who present an exposure risk to others in their household.

The following groups of individuals have underlying risk factors for severe disease and may require hospitalisation. Cases involving the below MUST be discussed with your SRIDC, and can be discussed with one of the HCID Centres:

  • Pregnant patients
  • Immunocompromised individuals
  • Children (16 years or under)

There are no longer regular activation calls to discuss patients with underlying risk factors and/or who are significantly impacted. NHS providers should manage cases themselves with advice from an expert centre or otherwise transfer the patient to an SRIDC. An MDT with an HCID Centre can be arranged.

Mpox cases in clade I (previously known as the Central Africa clade)

Future confirmed mpox cases with disease caused by clade I virus MUST continue to be managed as HCIDs as the clinical outcomes may not necessarily be benign.

Suspected/probable clade I cases (recent travel to Central Africa or known contact with a clade I case) must also be managed as a suspected HCID case until either mpox has been excluded, or clade I infection has been excluded, as the cause of mpox by typing the virus.

Yours sincerely,

Stephen Groves, Director of Emergency Preparedness, Resilience and Response, NHS England.