The UK Health Security Agency (UKHSA) has updated its guidance to advise health professionals to be aware of a new more fatal variant of mpox, currently spreading in parts of central and East Africa.

The UKHSA warning, issued today, comes after the World Health Organization (WHO) declared mpox a global public health emergency yesterday.

There are particular concerns over the new Clade 1 variant of the disease that has a high fatality rate.

UK health professionals should be aware of the risk of mpox exposure where there is a travel history to Democratic Republic of the Congo (DRC), Republic of the Congo, Central African Republic, Burundi, Rwanda, Uganda, Kenya, Cameroon, and Gabon, UKHSA said.

There may also be a risk associated with Angola, South Sudan, Tanzania and Zambia.

All laboratory-confirmed mpox (monkeypox) Clade I cases should be managed as a high consequence infectious disease (HCID), it added.

Yesterday, WHO director-general Dr Tedros Adhanom Ghebreyesus said that an upsurge of mpox in the DRC and a growing number of countries in Africa ‘constitutes a public health emergency of international concern’.

The announcement came after an emergency committee met to review data from affected countries and concluded it could spread to further countries in Africa as well as outside the continent.

‘A co-ordinated international response is essential to stop this outbreak and save lives,’ Dr Tedros said.

The previous mpox outbreak in 2022 was caused by a milder version of the infection – known as Clade 2. The current concern is over the spread of Clade 1, or more specifically a variant called Clade 1b which was first noted in September and has spread rapidly.

Since the start of the year, there have been more than 15,600 cases of mpox in the DRC, with at least 537 deaths, WHO said.

In the past month, over 100 laboratory-confirmed cases of clade 1b have also been reported in Burundi, Kenya, Rwanda and Uganda for the first time.

The previous mpox outbreak in the UK in 2022 saw more than 3,700 confirmed cases. Vaccination was offered to gay, bisexual and other men who have sex with men (GBMSM) who were at the highest risk of infection.

Professor Dimie Ogoina, chair of the emergency committee convened to review the latest data, said: ‘The current upsurge of mpox in parts of Africa, along with the spread of a new sexually transmissible strain of the monkeypox virus, is an emergency, not only for Africa, but for the entire globe.

Mpox, originating in Africa, was neglected there, and later caused a global outbreak in 2022. It is time to act decisively to prevent history from repeating itself.’

Dr Meera Chand, deputy director at UKHSA, said: ‘The risk to the UK population is currently considered low.

‘However, planning is underway to prepare for any cases that we might see in the UK.

‘This includes ensuring that clinicians are aware and able to recognise cases promptly, that rapid testing is available, and that protocols are developed for the safe clinical care of people who have the infection and the prevention of onward transmission.’

Dr Brian Ferguson, associate professor of immunology at the University of Cambridge, said: ‘The situation is concerning because of the spread of the clade 1b virus, which is considered to cause more severe disease, and because there are many children being infected in DRC during this new outbreak. 40% of cases are in children under 5 years old.’

He added that even though there are existing effective vaccines, there are not enough doses and they are not being getting to where they are needed.

‘The WHO is attempting to address these issues, but this requires greater international effort to produce and deliver vaccines.’

This article first appeared in our sister title, Pulse.