Analysis shows mpox lurked in Nigeria for 8 years before igniting global 2022 outbreak
June 6, 2025
A groundbreaking gene-tracking study published in Nature confirms that clade 2 mpox circulated in Nigeria undetected for eight years before triggering the 2022 global outbreak. Researchers estimate the virus first infected humans in southern Nigeria in 2014 and spread silently due to poor surveillance. Of 118 genomes analyzed, nearly all Nigerian cases showed sustained human-to-human transmission, while Cameroon cases reflected animal spillover. Lead author Edyth Parker stressed that limited access to vaccines, diagnostics, and surveillance tools in Africa facilitated the unchecked spread. The findings are a stark reminder: neglecting local epidemics endangers global health.
A new study in Nature reveals that the clade 2 mpox virus, responsible for the 2022 global outbreak, circulated undetected in Nigeria for nearly a decade. Using extensive genomic analysis from 118 viral samples collected in Nigeria and Cameroon between 2018 and 2023, researchers estimate the virus first emerged in animals in November 2013 and spilled into humans in southern Nigeria by August 2014. It spread to 11 Nigerian states before cases were formally detected in 2017.
The study’s findings, based on the largest mpox genomic dataset to date, show that 105 of 109 Nigerian cases were from sustained human-to-human transmission. In contrast, all nine Cameroonian samples were due to zoonotic spillover, highlighting regional variation in transmission dynamics.
Lead author Dr. Edyth Parker emphasized that global neglect of African epidemics directly contributed to the international crisis. “We could have very easily prevented the 2022 multi-country outbreak,” she said, “if countries in Africa were given better access to therapeutics, vaccines, and surveillance technologies.” The authors call for enhanced wildlife surveillance, particularly in forest systems, and improved genomic and human case monitoring.
The study also underscores a continual risk of re-emergence. With zoonotic transmission still occurring in Nigeria and Cameroon’s forested regions, and clade 2b now endemic in West Africa, under-ascertainment and sparse data remain critical obstacles to effective containment.
Ultimately, the research exposes how global health inequities perpetuate both suffering and risk. As Parker noted, “Mpox is no longer just a zoonotic virus in Nigeria; this is very much a human virus.” Without equitable investment in surveillance and response capacity, future pandemics are not a question of if—but when. This study is a call to action: global health security depends on local investment and preparedness.