The mpox outbreak that began in May 2022 represented a significant and unusual shift in the epidemiology of the disease. Monkeypox, now referred to as mpox, is a viral zoonotic disease caused by the monkeypox virus, which belongs to the same family as smallpox (Orthopoxvirus). Historically, mpox has been confined primarily to remote parts of Central and West Africa, particularly in countries such as the Democratic Republic of Congo and Nigeria, where human cases are typically linked to contact with infected animals.
First Reported Case in May 2022
On May 6, 2022, the UK Health Security Agency (UKHSA) confirmed the first case of mpox in the United Kingdom. The individual had traveled from Nigeria and presented with characteristic symptoms, including fever, rash, and swollen lymph nodes. While mpox is not novel in Africa, its detection in a traveler outside the continent initially appeared to be an isolated incident.
However, within just a few days, additional cases began appearing in individuals with no travel history to endemic regions, suggesting human-to-human transmission within Europe. This raised immediate concern among infectious disease specialists and public health agencies, as this mode of transmission was previously considered rare and largely limited to close family contacts or healthcare workers without proper protective equipment.
Unprecedented Spread
Throughout May 2022, reports of mpox cases surged across multiple non-endemic countries, including Portugal, Spain, Canada, and the United States. According to the World Health Organization (WHO), the virus spread through close physical contact, including skin-to-skin contact and shared linens or clothing, and many of the early clusters were identified within social networks of men who have sex with men (MSM). This mode of spread emphasized the need for non-stigmatizing, inclusive public health messaging to raise awareness and guide preventive measures.
By the end of May, over 20 countries had confirmed cases of mpox, totaling more than 300 infections, many of which had no direct epidemiological links to travel or known exposure in endemic countries. This signaled the first sustained chain of transmission outside of Africa, and it was officially recognized by global health authorities as an emerging international outbreak.
Genomic Analysis and Investigation
Initial genomic sequencing of the virus identified that the strain circulating in 2022 belonged to the West African clade, which is known to cause less severe illness compared to the Central African clade. Nonetheless, the sudden expansion of cases in non-endemic countries triggered rapid research and surveillance efforts. Scientists and epidemiologists collaborated globally to study the genetic mutations of the virus, assess its transmissibility, and identify potential changes in viral behavior.
The mpox outbreak of May 2022 thus became a critical inflection point for how infectious diseases with pandemic potential are identified and responded to in an interconnected world. It highlighted vulnerabilities in disease surveillance systems and underscored the role of international cooperation, transparency, and rapid data sharing in containing emerging threats.
