England Identifies High-Threat Pathogens, Including Mpox

A new report is the first annual summary of infectious diseases impacting England, with data from 2023 to early 2025, and recognises the cross-border nature of health threats.

Published by the UK Health Security Agency (UKHSA) in late March 2025, this report summarizes the status of infections important to public health over the most recent years for which data have been published. It also details the efforts undertaken by the Agency and its partners to control and prevent the spread of these infections and to mitigate their harmful effects.

"This report sets out the current picture of a number of diseases, but it is also full of examples of the proactive work we do to prepare for and respond to infectious disease threats, from surveillance of avian influenza at farms where zoonotic outbreaks have occurred, to our early detection and management of the first clade 1b mpox cases in the England," wrote Dame Jenny Harries Chief Executive, UKHSA.

Mpox is a zoonotic infection caused by the monkeypox virus, mainly in West and Central Africa. Before 2022, cases diagnosed in the UK had been imported from countries where mpox is endemic or contacts with links to imported cases. Between 2018 and 2021, there were 7 cases of mpox in the UK.

Following a spike in clade 1b cases in 2022, the number of cases in England has steadily diminished.

However, in August 2024, the WHO declared mpox a Public Health Emergency of International Concern. This followed the identification and rapid spread of clade Ib in the Eastern Democratic Republic of Congo and some neighbouring countries.

As of March 26, 2025, eleven cases of clade Ib have been reported in the UK.

Seven cases had recent travel links to affected African countries, one of which led to onward transmission to three household contacts in the UK, but no further spread.

The UKHSA wrote, 'this mpox outbreak continues to evolve and will lead to further exported (cases) outside the African region.'

In the UK, an effective mpox vaccine is available to prevent both clades.

Bavarian Nordic A/S JYNNEOS® (MVA-BN®, IMVAMUNE®) is a two-dose vaccine offered throughout England and is commercially available in the U.S. JYNNEOS has been added to the World Health Organization prequalification list.