The UK Health Security Agency (UKHSA) has identified a new recombinant mpox virus in England in an individual who had recently travelled to Asia. Genomic sequencing revealed that the new virus strain had elements of clade 1b and 11b mpox, which are both currently circulating.
“Our genomic testing has enabled us to detect this new mpox strain. It’s normal for viruses to evolve, and further analysis will help us understand more about how mpox is changing,” said Katy Sinka, MSc, head of sexually transmitted infections at UKHSA, in a press statement.
It’s normal for viruses to evolve, and further analysis will help us understand more about how mpox is changing.
“Although mpox infection is mild for many, it can be severe. Getting vaccinated is a proven effective way to protect yourself against severe disease, so please make sure to get the jab if you are eligible,” Sina said.
In the United Kingdom, routine vaccination against mpox is recommended for several groups, including men who have sex with men (MSM) and those who have multiple sexual partners, participate in group sex, or visit sex-on-premises venues.
Clade 11b is the less severe strain of virus responsible for the global epidemic of mpox cases in 2022 among MSM in non-endemic countries, including the United Kingdom and United States. Clade 1b is a newer variant first identified in the Democratic Republic of the Congo (DRC) in 2024. It is more transmissible and virulent than clade 11b but has not been widely seen outside of Africa until this fall.
WHO alerts to community spread of clade 1b
However, late last week the World Health Organization (WHO) published a new alert on broader transmission of clade 1b mpox virus in several non-endemic countries, including the United States.
The WHO said more MSM in countries that were previously unaffected or only reporting cases linked to travel, are now seeing suggestions of community transmission. Since September, several countries across four of six WHO regions have confirmed 43 clade 1b mpox infections in individuals with no recent travel reported.
“Based on this, Italy, Malaysia, the Netherlands, Portugal, Spain, and the United States of America are now considered to be experiencing community transmission of clade Ib MPXV [mpox virus],” the WHO said. “In addition, travel-related cases continue to be reported in many countries.”
Among the 43 cases, 22 were in MSM, while others were linked to travel or household exposures. In the United States, the first locally acquired case of clade 1b was identified in a resident of Long Beach, California, with no travel history.
“WHO assesses the public health risk posed by clade Ib MPXV as moderate for men who have sex with men with new and/or multiple partners, and the risk to the general population as low,” the report says.
Today, the WHO produced an external situation report on global mpox. So far this year, there have been 47,980 mpox cases reported around the world. From mid-October to mid-November, there were 584 cases in the DRC and 332 cases in Liberia. Twenty-one African countries reported active transmission in October and November. Mali is the latest country to report mpox for the first time.
Overall, 75% of global mpox activity is occurring in Africa.
