Ebola has reached displacement camps in eastern Congo, and a camp evacuation has scattered the people health teams were monitoring. Here is what we know.

The outbreak: Congo is fighting Ebola caused by the Bundibugyo strain. Reuters reports 88 cases and 56 deaths in displacement sites.

The crisis: on October 1, soldiers entered the Kigonze camp to search for weapons, clashing with militia. About 19,000 people fled and the camp was abandoned.

The tracing gap: health teams were monitoring about 1,000 Ebola contacts at Kigonze. Only around one in five had been traced when the fighting started, and a screening transit centre was burned.

Why it matters: displaced contacts travelling to new areas can seed fresh chains of transmission, undoing weeks of containment work.

The obstacle: eastern Congo’s decades-long conflict keeps undermining outbreak response. Aid agencies say insecurity, not medicine, is the biggest barrier to ending Ebola.

The Bundibugyo strain is one of six known Ebola virus species. It is less deadly than the Zaire strain behind the 2014-16 West Africa epidemic, but it still kills a large share of those infected.