The World Health Organization declared an Ebola outbreak in Democratic Republic of Congo and Uganda a public health emergency of international concern, warning that a rare virus strain with no approved vaccine or treatment may already be spreading more widely than detected

The agency stopped short of declaring a “pandemic emergency,” a new category created under revised international health regulations after Covid-19.

Bundibugyo ebolavirus is one of the rarest Ebola species known to infect humans. It has caused only two previous documented outbreaks — in Uganda in 2007 and eastern Congo in 2012. Combined, those outbreaks resulted in fewer cases than the current epidemic has already generated.