Guidance

Operational mpox HCID (Clade I) case definition

This guidance is for healthcare workers and describes the operational case definitions to determine a suspected or confirmed case of HCID (clade I) mpox.

From:
UK Health Security Agency
Published
14 August 2024
Last updated
26 September 2024 — See all updates

This guidance was withdrawn on

The HCID case definition of mpox is available in the guidance on when to suspect a case of mpox. The list of countries affected by mpox is now available.

Operational case definition

All laboratory confirmed mpox clade I cases should be managed as a high consequence infectious disease (HCID).

Operational management as HCID

Patients with confirmed or clinically suspected mpox but clade not yet known should be managed as a HCID mpox case whilst further information is pending, if either (or both):

  • there is a travel history to the Democratic Republic of the Congo (DRC) or specified countries where there may be a risk of clade I exposure, or a link to a suspected case from those countries (listed below), within 21 days of symptom onset

Or:

  • there is an epidemiological link to a case of clade I mpox within 21 days of symptom onset

Cases when mpox is not considered an HCID

Mpox is not considered an HCID in the following circumstances:

  • a case has a laboratory confirmed clade II MPXV infection

Or:

  • a confirmed or clinically suspected mpox case of an unknown clade and none of the epidemiological characteristics listed above in Operational management as HCID apply

Countries where there may be a risk of clade I exposure

Given the rapid spread of clade I in the African Region, please check the UKHSA mpox pages regularly for any updates to the countries included.

The countries reporting laboratory-confirmed clade I mpox (historic or current) include:

  • DRC
  • Republic of the Congo
  • Central African Republic
  • Burundi
  • Rwanda
  • Uganda
  • Kenya
  • Cameroon
  • Gabon

The countries where there may be a risk of clade I mpox exposure (base on sharing a border with the DRC) currently include:

  • Angola
  • South Sudan
  • Tanzania
  • Zambia

Figure 1. African Region countries reporting laboratory confirmed clade I mpox or where there may be a risk of clade I mpox exposure

Management of cases

Clinicians should be alert to the possibility of clade I mpox if there is a link to the specified countries in the African region (as listed), and those treating patients with suspected mpox who may meet the operational definition of an HCID (as outlined above) should discuss with the Imported fever service (0844 778 8990) to expedite testing. Patients with severe disease should also be discussed with the Imported Fever Service.

Confirmed or suspected clade I cases should be managed as an HCID requiring transmission-based precautions and enhanced personal protective equipment (PPE) as outlined in the NHS guidance on infection prevention and control measures for clinically suspected and confirmed cases of mpox in healthcare settings.

Updates to this page

Published 14 August 2024
Last updated 26 September 2024 + show all updates

  1. Updated links to direct to the NHS guidance on IPC measures for mpox cases in healthcare settings.

  2. First published.

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