The United Kingdom has reported two new cases of local transmission of the contagious Clade Ib mpox strain, increasing the total number of confirmed cases in the country to three. These cases were identified in individuals sharing a residence with a previously confirmed case who had traveled to several African countries currently experiencing mpox outbreaks.
Dr. Hans Henri P. Kluge, the World Health Organization (WHO) regional director for Europe, emphasized that while the overall risk to the general population in the UK and the wider region remains low, the local transmission of Clade Ib mpox underscores the need for enhanced surveillance and preparedness measures, including rapid contact tracing of suspected and confirmed cases.
This strain of mpox, first detected in Europe in individuals in Sweden and Germany with recent travel links to Africa, has not seen further cases or local transmissions beyond these instances, as per the European Center for Disease Prevention and Control (ECDC). The recent cases in the UK mark the first instance of local transmission of this particular mpox strain in Europe, prompting a vigilant response from healthcare professionals.
Professor Susan Hopkins, the chief medical adviser for the UK Health Security Agency (HSA), stated that the nature of mpox makes it highly contagious within households due to close contact. “It is not unexpected to see further cases within the same household,” she explained. The HSA is actively working with partners to ensure that all contacts of the cases are identified and informed to mitigate the risk of further transmission.
The WHO has noted that mpox primarily spreads through close physical contact, including sexual contact, or by touching contaminated items like bedding or clothing. In response to the outbreak, WHO/Europe advises the public to avoid close contact with anyone showing symptoms, maintain good hand hygiene, and consider vaccination if available, particularly when traveling to regions where mpox outbreaks are occurring.
Dr. Jonas Albarnaz, a fellow at the Pirbright Institute, remarked that these two additional cases might represent the first instance of household transmission of Clade 1b mpox outside Africa. However, further investigation is necessary to confirm if the transmission occurred within the UK. He also highlighted that the detection of cases among household contacts demonstrates the effectiveness of the surveillance and contact-tracing efforts implemented by the health authorities.
