Mpox (monkey pox) outbreak: epidemiological overview, 6 July 2023

This epidemiological snapshot provides an update on the number of confirmed and highly probable cases of mpox in England, Northern Ireland, Scotland and Wales.

Mpox is a zoonotic infection, caused by the monkeypox virus, which occurs mainly in West and Central Africa. Prior to 2022, cases diagnosed in the UK had either been imported from countries where mpox is endemic or contacts with documented epidemiological links to imported cases. Between 2018 and 2021 there had been 7 cases of mpox in the UK. Of these, 4 were imported, 2 were cases in household contacts and one was a case in a health worker involved in the management of an imported case. There has been no documented community transmission in previous outbreaks.

THE UK mpox control strategy is to eliminate person-to-person transmission of mpox in the UK. The elimination of the disease is defined by the World Health Organization (WHO) European Region as the absence of locally acquired cases for a period of at least 3 months, in the presence of an effective surveillance system.

Current epidemiological situation as of June 30, 2023

Detection of cases of mpox infection, acquired in the UK, was confirmed in England from 6 May 2022. The outbreak mainly affected gay, bisexual and other men who have sex with men with no history documented travel to endemic countries.

Specimens suspected of mpox that are positive using an mpox polymerase chain reaction (PCR) test are classified as confirmed cases. Positive samples using an orthopox PCR test are classified as highly probable cases. Orthopox is the group of viruses that includes mpox. The figures below combine these two categories.

Up to 31 December 2022, 3,732 confirmed and highly probable cases of mpox have been reported in the UK. Of these, 3,553 were in England, 34 in Northern Ireland, 97 in Scotland and 48 in Wales.

In 2023 (up to June 30, 2023), a further 29 cases of mpox have been reported in the UK. Of these, 28 were in England (14 cases were presumed to have acquired mpox in the UK, 11 were acquired outside the UK and 3 awaiting classification) and one was in Scotland (one imported case acquired outside the UK). Between June 1 and June 30, 2023, 8 new cases were reported, including 7 in London.

Table 1: Number of confirmed and highly probable cases of mpox by country of residence in the UK, 6 May 2022 to 30 June 2023*

*Based on data extracted July 3, 2023.

** Figures for 2022 start from 6 May 2022 and combine cases acquired and imported into the UK.

Data sources

Surveillance data for Mpox in England is based on Rare and Imported Pathogens Laboratory mpox and orthopox virus test results (RIPL), which is the UK Health Security Agency (UKHSA) mpox reference laboratory and other UK laboratories performing mpox and orthopox testing.

The number of confirmed cases in Wales, Northern Ireland and Scotland is subject to UKHSA respectively by Public Health Wales, Public Health Agency Northern Ireland and Public Health Scotland.

Information about this publication

These figures are used for official reporting on the number of confirmed cases of mpox in the UK.

England’s counts may differ from those published in the Notifications of infectious diseases (NOID) weekly report of responsible officers. This is due to differences in when the data is compiled and differences in the treatment of duplicate data (for example, if a person has been tested more than once but insufficient information is provided for the identify).

As mpox continues to be a reportable infection, please see UKHSAIt is NOID reports for weekly updates (but not cumulative totals) of reported laboratory cases of mpox in England.

Although data cleaning is done routinely, corrections can be applied between reports, such as updates to patient information and deletion of quality assurance samples from laboratory monitoring systems.

Additional Resources

Mpox outbreak: technical briefings

Mpox: case definitions

Mpox contact tracing guide: contact classification and advice for vaccination and follow-up