Two cases have also been confirmed in neighbouring Uganda.
“It would be a big mistake to underestimate it, especially with a virus with this strain, Bundibugyo, (for) which we don’t have the vaccine,” Mohamed Yakub Janabi said in an interview at WHO headquarters in Geneva.
“So I would really encourage everyone, let’s help each other, we can bring this thing into control,” he said.
He added that the outbreak of Ebola in Congo has had relatively little global attention compared with this month’s hantavirus outbreak, which affected cruise ship passengers from 23 countries including major powers.
“You just need one contact case to put all of us at risk, so my wish and prayer is that we should give (Ebola) the attention it deserves,” he said.
Ebola is an often-fatal virus that causes fever, body aches, vomiting and diarrhoea.
It spreads through direct contact with the bodily fluids of infected people, contaminated materials or people who have died from the disease.
Janabi declined to comment on the expected duration and scale of the current outbreak, saying experts on the ground were in the process of assessing this.
The “hyperdynamic movement of the people” made it hard to gauge the situation, he said, adding that efforts to scale up testing, infection prevention measures and community engagement were underway.
A dispute over a victim’s body that led to the burning of Ebola treatment tents pointed to the importance of building trust, he said.
Another challenge was that epidemiologists have yet to find the initial person infected, he added, saying this was important for identifying and isolating the initial web of contacts.