BUNIA: Four out of every five new Ebola cases in parts of Democratic Republic of Congo have no known link to existing patients, a senior World Health Organization official said, warning that the true scale of the outbreak could be two to four times larger than official data suggest.

The figures underscore the challenges facing health workers as they battle to contain the outbreak in the country’s northeast, which has so far infected 1,792 people and killed 625, according to government data released on Thursday.

“Eighty percent ‌of the… ‌new patients confirmed are coming outside of known contact lists” ‌in ⁠the heart of ⁠the outbreak in Bunia, Ituri province, WHO Emergencies Director Chikwe Ihekweazu told Reuters in an interview late on Thursday.

In areas with fewer cases, like North Kivu province, almost all new cases are coming from the contact lists, he added, a sign of some progress.

TESTING POINTS TO INTENSE COMMUNITY TRANSMISSION