Spain Confirms First Non-African Human Transmission of Mpox Clade 1b

Health authorities in Spain have confirmed the first case of human-to-human transmission of mpox clade 1b outside Africa. This significant development sheds light on the virus’s spread beyond its endemic regions, highlighting the ongoing global health challenge posed by this infection.

The case involves a 49-year-old man from Madrid, who presented to a clinic on October 10, 2023, with symptoms including a genital lesion and painful lymph node swelling in the groin. Notably, the patient had not traveled to Africa, a fact that distinguishes this case from previous reports. He had received two doses of the Imvanex smallpox/mpox vaccine and disclosed recent sexual contact with two partners, neither of whom had visited mpox-endemic regions.

According to a report published in the International Journal of Infectious Diseases, doctors confirmed the presence of mpox clade 1b through PCR testing of the lesion after ruling out other sexually transmitted infections. Researchers described the case as unprecedented, as all previously reported clade 1b infections outside Africa were linked either to travel or direct contact with individuals who had visited endemic areas.

Spanish health authorities noted that the patient had no known epidemiological connections to existing clade 1b cases in the country. To date, only one other clade 1b case has been reported in Spain, involving a traveler returning from Tanzania, and there is no relation to the newly identified infection.

Global Context and Health Implications

Human-to-human transmission of mpox clade 1b has been sustained in several African nations, with the first known case outside Africa detected in a Swedish traveler returning from an endemic area. Since then, sporadic cases have emerged globally, predominantly linked to recent travel or contact with travelers.

Health experts emphasize the need for heightened vigilance and preventive measures to mitigate clinical and public health impacts, particularly among groups identified as more vulnerable. These include individuals living with HIV, men who have sex with men, and those with multiple sexual partners.

According to the World Health Organization’s latest update, there were 2,501 new confirmed mpox cases reported globally in October, resulting in 12 deaths across 44 countries. This data underscores the importance of continued monitoring and containment efforts to address the ongoing threat posed by mpox.

As Spain navigates this complex situation, health authorities are working to ensure public awareness and preparedness in response to the evolving landscape of mpox transmission.