Since late last month, there have been four cases of a new strain of mpox detected in Britain. Image courtesy of National Institute of Allergy and Infectious Diseases/CDC/Release
"We are working with partners to make sure all contacts of the cases are identified and contacted to reduce the risk of further spread," Susan Hopkins, chief medical adviser at UK Health Security Agency, said in a statement.
Britain confirmed its first case of Clade Ib late last month, stating the patient had recently traveled to African nations seeing community spread of the disease.
Two additional cases of the initial patient's household were detected earlier this week, marking the first locally transmitted Clade Ib cases in Europe, according to World Health Organization.
British health officials said the case announced Wednesday has been isolating since being identified as a contact with the first case, and no additional contact tracing is required.
Mpox, formerly known as Monkeypox, is a viral illness transmitted through close contact with an infected person that can be fatal.
Britain experienced an outbreak of mpox in 2022. As of July of that year, there were 1,517 confirmed confirmed cases of the virus, with a high proportion of those infected being London residents, primarily men who have sex with other men.
Clade Ib is a different strain than the one responsible for Britain's outbreak and was first reported in the Democratic Republic of Congo last year. It has since spread to nonendemic countries, including Burundi, Kenya, Rwanda and Uganda.
On Sunday, the Africa Centers for Disease Control and Prevention said there have been 49,310 suspected cases of mpox in the continent this year, of which more than 10,600 have been confirmed. A total of 1,059 deaths have been attributed to the virus. It did not differentiate between the virus' different strains.
A majority of the confirmed cases and deaths were in the DRC.
Cases of Clade Ib have also been diagnosed in Thailand, Sweden and Germany.
The WHO said in a statement Tuesday that though risk of transmission is low in Britain, the local spread of the virus should be the impetus for health systems across the region to prepare for rapid contact tracing of suspected and confirmed cases.
"I commend the United Kingdom for its prompt action to detect and control this cluster, with clear and transparent communication to ensure timely reporting, and data sharing," Dr. Hans Henri P. Kluge, WHO regional director for Europe, said in a statement.
"Once again, I urge all 53 Member States of the WHO European Region to follow the WHO Standing recommendations and enhance surveillance to detect clades I and II of mpox, issue sound public health advice, and strengthen access to vaccines and antivirals."
Britain purchased more than 150,000 doses of mpox vaccine in mid-September in case of potential Clade Ib cases.