Health authorities battling an Ebola outbreak in the Democratic Republic of the Congo have identified only about 30,000 people who may have been exposed to the virus, far short of the more than 400,000 contacts expected to be traced, a senior African health official told Reuters.
Dr. Jean Kaseya, director-general of the Africa Centres for Disease Control and Prevention, said the gap underscored how deeply the outbreak remained embedded in communities despite signs of progress.
More than 80% of newly confirmed cases were being detected among people who were not already on contact lists, suggesting transmission was continuing beyond the reach of surveillance efforts.
For every confirmed Ebola case, 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 U.N. General Assembly in New York.
With nearly 7,900 confirmed cases, that would translate into about 474,000 contacts. "But currently, we have just 30,000 people in the contact list," Kaseya said.
"When the outbreak is at community level, we cannot talk about control," he added.
The Ebola outbreak was detected in May and has become the largest Ebola outbreak ever recorded in the Democratic Republic of the Congo. The outbreak is also approaching the scale of the 2014-2016 Ebola epidemic in West Africa, which remains the largest Ebola outbreak on record.
The World Health Organization said Friday that the outbreak had spread to two additional health zones, Bulu in Sud-Ubangi province and Dungu in Haut-Uele province near the South Sudan border, bringing the number of affected health zones to 63 across seven provinces.
Last week, United Nations and Congolese government officials said there were signs transmission was slowing in some of the worst-affected parts of Ituri, the epicenter of the outbreak.
Congolese Prime Minister Judith Suminwa Tuluka described the outbreak Wednesday as a major test for the country and said the response had begun producing tangible results.
"We see some improvement, but the outbreak is still serious," Kaseya said.
Even if the Democratic Republic of the Congo were 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 because it would mean health authorities knew where transmission was occurring.
Kaseya declined to predict when the outbreak would be brought under control, saying he wanted to see substantially better surveillance and other improvements before putting a timetable on the response.
"If there is a game I didn't want to play since we declared this outbreak, it was to predict when we can bring this outbreak under control," he said.
Kaseya said that if new confirmed cases were identified through contact lists, zero deaths were occurring in communities and there were no new infections among health care workers, he could be in a position to forecast whether the outbreak could be fully controlled within four weeks.
But for now, he said, the high proportion of cases being discovered outside contact lists remained evidence of uncontrolled community transmission.
Africa CDC said nearly $2.9 billion was pledged for the Ebola response at a U.S.-convened meeting in New York on Thursday, including $886 million from the United States.
