Monkeypox has likely been spreading in non-endemic areas unnoticed for some time, CNBC reports.
It adds that Tedros Adhanom Ghebreyesus, the director-general of the World Health Organization, says that the virus's apparent sudden emergence in multiple countries indicates that such undetected circulation was taking place. Additionally, a new analysis posted to virological.org this week from University of Edinburgh researchers suggests there has been sustained human-to-human transmission of monkeypox since 2017, according to CNN. The researchers there point out that the 2022 monkeypox outbreak samples descend from a clade that includes cases from Singapore, Israel, Nigeria, and the UK that date back to between 2017 and 2019.
Michael Worobey from the University of Arizona adds at CNN that this rather silent spread also raises the question of whether monkeypox could become endemic outside of West and Central Africa. CNN adds, though, that officials from the US Centers for Disease Control and Prevention say it is too early to tell if that could be the case and that they are "hopeful" that that will not happen.