New Delhi, Dec 13 (NationPress) Health authorities in Spain have confirmed the first instance of human-to-human transmission of mpox clade 1b outside the endemic regions of Africa. Mpox is a viral disease that spreads through close contact, leading to symptoms such as fever, swollen lymph nodes, and skin rashes. The primary route of transmission is through skin-to-skin contact.

The mpox clade 1b is a highly infectious variant that sprang from an outbreak in the Democratic Republic of the Congo in 2023.

This case, published in the International Journal of Infectious Diseases, details that a 49-year-old man had received two doses of the Imvanex smallpox/mpox vaccine and had no known travel history.

The patient sought medical attention in Madrid on October 10, presenting with a solitary genital ulcer and swollen, painful lymph nodes in the groin.

He reported sexual contact with two local partners, neither of whom had traveled to endemic regions. After excluding other sexually transmitted infections, health authorities confirmed the presence of mpox clade 1b through a polymerase chain reaction (PCR) test on the lesion.

“This is the first documented case of Mpox clade 1b without any travel history to Africa for either the patient or their previous sexual contacts, as reported by Spanish Public Health authorities on October 10, 2025,” stated Jorge-Alfredo Pérez-García from Centro Sanitario Sandoval/Hospital Clínico San Carlos in Spain.

“Previously, cases had been linked to travel to regions with known Mpox clade 1b transmission, or direct contact with individuals who traveled there,” he added.

In Spain, there is only one other reported case of this clade, involving a patient who had traveled to Tanzania and was exposed less than 21 days prior, specifically on September 22, with no link to the current case.

A number of African nations have ongoing human-to-human transmission of mpox clade 1b. The first case reported outside Africa was a Swedish national returning from an endemic region.

Since then, cases have been identified in countries outside of Africa, predominantly among individuals who recently traveled to endemic areas or had contact with travelers.

Health officials are urging the implementation of necessary measures to mitigate both clinical and public health impacts, particularly among vulnerable groups identified in prior Mpox outbreaks since 2022, such as individuals living with HIV, men who have sex with men, and those with multiple sexual partners.

According to the World Health Organization (WHO), a total of 2,501 new confirmed cases, including 12 deaths due to mpox, were reported from 44 countries in October.