Ebola outbreak in DRC: failures in contact tracing make control difficult

Health authorities fighting the Ebola outbreak in the Democratic Republic of Congo have identified only about 30,000 people who may have been exposed to the virus, a fraction of the more than 400,000 expected to be found through contact tracing, a senior African health official told Reuters.

Jean Kaseya, director general of the African Centers for Disease Control and Prevention (Africa CDC), said this lag shows that the outbreak remains rooted in communities, despite signs of progress.

More than 80% of new confirmed cases were being detected among people who were not yet on contact lists, indicating that transmission continues to occur beyond the reach of surveillance efforts.

For every confirmed case of Ebola, health authorities would expect to identify about 60 people who had direct or indirect contact with the infected person, Kaseya told Reuters on Friday on the sidelines of the UN General Assembly in New York.

With around 7,000 confirmed cases, this would correspond to approximately 420,000 contacts. "But currently, we only have 30,000 people on the contact list," Kaseya said.

"When the outbreak is widespread in communities, we cannot talk about control," he added.

The Ebola outbreak was detected in May and is already the second largest ever recorded, behind only the one that occurred in West Africa between 2014 and 2016.

The WHO (World Health Organization) reported on Friday that the outbreak had spread to two other health zones: Bulu, in Sud Ubangi province, and Dungu, in Haut-Uele province, close to the border with South Sudan. As a result, the number of affected health zones reached 63, spread across seven provinces.

Last week, United Nations and Congolese government officials said there were signs of slowing transmission in some of the worst-affected areas of Ituri, the epicenter of the outbreak.

Congolese Prime Minister Judith Suminwa Tuluka called the outbreak on Wednesday a major test for the country and said response actions had begun to produce concrete results.

"We see some improvement, but the outbreak is still serious," Kaseya said.

Even if Congo was still recording 50, 60 or 70 new cases a day, Kaseya said he would be less concerned if they were people already identified and monitored as contacts, as that would mean health authorities would know where transmission was occurring.

Kaseya declined to predict when the outbreak would be controlled, saying he wanted to see substantially better surveillance and other advances before establishing a timeline for the response.

"If there's one game I haven't wanted to play since we declared this outbreak, it's predicting when we'll get it under control," he said.

Kaseya said that if new confirmed cases were identified through contact lists, no deaths occurred in communities and there were no new infections among healthcare workers, he might be in a position to predict whether the outbreak could be fully controlled within four weeks.

But for now, he said, the high proportion of cases discovered outside contact lists remains evidence of uncontrolled community transmission.