Health officials throughout Europe are reassessing the mpox threat after scientists confirmed the discovery of a recombinant, or hybrid, mpox virus strain in the United Kingdom, although new illnesses in the region increased dramatically in a single month. 

According to the World Health Organisation (WHO), mpox incidence in Europe surged by 120% in November 2025, reversing a reduction that began earlier in the year. The increase correlates with signs that the virus is not just spreading but also changing its genetic makeup, potentially complicating surveillance and management. 

The UK instance involves a recombinant strain with genetic material from Clade Ib and Clade IIb, two separate branches of the mpox virus. Simply said, this indicates that two separate versions of the virus attacked the same individual and mingled their genetic material, resulting in a new hybrid. Scientists refer to this process as viral recombination. 

"The discovery of a recombinant strain in the UK is a wake-up call. It informs us that allowing multiple clades of mpox to circulate at the same time is essentially providing the virus a laboratory in which to experiment on itself," an expert said. 

The World Health Organisation was alerted of the UK case on December 2, 2025. The infection was associated with travel from Asia, demonstrating how global migration continues to affect the outbreak. While there is currently no proof that the hybrid strain spreads faster or produces more severe sickness, scientists point out that there is insufficient data to form solid conclusions. 

European Renaissance and new territories 

According to WHO surveillance data, 96 countries reported mpox cases in 2025, with 50,751 confirmed illnesses and 206 deaths recorded worldwide from January to November. Despite dropping numbers in most places, Europe saw an increase in cases, with 380 reported in November compared to 174 in October. 

The virus's geographic spread is also expanding. Romania has confirmed its first Clade Ib case, while Spain and the Netherlands are still reporting community transmission of the same clade among people who have not travelled recently. Mali has reported the first mpox cases in Africa, highlighting the possibility of cross-border spread. 

The blind spot in the centre 

Despite these gains, the WHO cautions that the global picture may be significantly incomplete. The Democratic Republic of the Congo (DRC) remains the core of the outbreak, accounting for the vast majority of new cases. However, since October, fewer than 20% of suspected cases in the DRC have received confirming tests. 

Because of this testing failure, official estimates may only represent a percentage of actual infections, creating a serious blind hole. Reduced testing has also resulted in decreasing positivity rates, but WHO cautions that this does not necessarily imply declining transmission. 

Mpox is an orthopoxvirus that can undergo recombination when various strains circulate together, according to current scientific knowledge. While this is a natural process, it creates difficulties when surveillance is ineffective and multiple clades expand simultaneously. 

The WHO maintains to define the risk as moderate for high-risk groups and low for the general population, asking countries to continue testing, genome sequencing, and cross-border collaboration through 2026.