Briefing Note 2024/059 Update on mpox clade Ib in UK – December 2024

This is an update to Briefing note 2024/049 issued on 30 October 2024.

UKHSA has updated its mpox clade I risk assessment as well as its assessment of global scenarios following further review of the international evidence, and the updated technical briefing was issued on 19 December 2024 (Mpox technical briefing 10).

There have now been five cases of mpox clade Ib detected in the UK, one imported case with onwards transmission to three household contacts, and one imported case without any onwards transmission to date (some contacts remain under follow up). Clade I mpox is classified as a high consequence infectious disease in the UK.

Given the continued expansion of the outbreak into countries with closer links to the UK, the ongoing risk of importation of mpox clade I is now considered medium. Transmission has been demonstrated within the UK and the risk of acquisition in the UK is low for the general population but may be medium for those individuals and groups more closely linked to travellers from affected countries.

All clinicians should note the increased risk of importation and risk of acquisition to some groups in the UK, and are reminded:

• To be aware of the guidance Mpox: guidance on when to suspect a case of mpox – GOV.UK and ensure that a travel history is taken from patients presenting with fever/rash.
• To consider mpox clade I in returned travellers from Clade I mpox: affected countries – GOV.UK where there is a compatible clinical syndrome.
• That input from infection services should be sought for febrile illness and rash without an identified cause in returning travellers returning from affected countries.
• Of the requirement to discuss suspected clade I mpox cases with the Imported Fever Service (0844 7788990) and, if advised by the IFS to progress to testing, to notify the local Health Protection Team.

Please follow link to download briefing in full.