In the Democratic Republic of Congo, health officials are warning an outbreak of Ebola could potentially explode, after the first confirmed case of the deadly virus was found in Mbandaka—a city of more than a million people. This is Peter Salama of the World Health Organization.

Peter Salama: “Urban Ebola is a very different phenomenon to rural Ebola, because we know that people in urban areas can have far more contacts, so that means that urban Ebola can result in an exponential increase in cases in a way that rural Ebola struggles to do.”

So far at least 45 people have been infected by the virus, with the death toll now at 25. An Ebola outbreak in West Africa in 2014 claimed more than 11,000 lives.