Ebola Outruns Containment in Eastern Congo as Contact Tracing Falters

(Bloomberg) -- Ebola is spreading faster than responders can track it in eastern Congo, where health workers managed to follow up with barely one in five identified contacts in a single day.

Authorities in the Democratic Republic of Congo reported 83 confirmed infections, 746 suspected cases and 1,603 identified contacts as of May 21, according to the health ministry. Yet health workers were able to follow up with only 342 contacts that day — about 21% of the total under monitoring — according to ministry data released Friday.

The figures suggest the response is falling behind the outbreak itself, even as governments and international agencies ramp up emergency measures after the World Health Organization declared the epidemic a public health emergency of international concern on May 17. 

The outbreak has now spread across three provinces including South Kivu, where officials confirmed a case this week near Bukavu, a major city near Congo’s border with Rwanda. Two cases were confirmed earlier this week in neighboring Uganda, while health officials warn that insecurity, population movements and distrust of authorities are complicating efforts to trace infections and isolate cases.

The epidemic is unfolding in “one of the most challenging operational environments possible,” the WHO’s emergency committee said Friday.

Tensions are already surfacing around containment measures. Relatives of a man who died at Rwampara Hospital near Bunia, the capital of Ituri province, where the outbreak was first detected, clashed with health workers after authorities refused to release the body for burial because of infection risks, according to local media reports. Ebola treatment tents run by the aid group Alima were set on fire during the unrest, and six patients fled the facility, including three confirmed Ebola cases, according to reports from the area.

The outbreak is caused by the rare Bundibugyo strain of Ebola, for which there is no approved vaccines or antibody treatments. The virus appears to have circulated undetected for months in Ituri province before authorities recognized what they were dealing with.

Testing Gaps

Health officials are now trying to track thousands of people who may have been exposed as infections spread through remote mining areas and urban centers including Bunia and Goma, cities with populations approaching 700,000 and 860,000 respectively.

More than 11 metric tons (12 tons) of emergency supplies — including protective equipment, treatment kits and materials for safe burials — have already been airlifted into Bunia, the WHO said Friday.

The latest ministry figures suggest confirmed transmission is spreading beyond the gold-mining hub of Mongbwalu, which was initially viewed as the epicenter. While Mongbwalu remains the largest suspected cluster, confirmed infections are increasingly concentrated in surrounding health zones including Rwampara and Bunia.

Nyankunde, home to a major referral hospital serving about 200,000 people, has also emerged as a growing cluster with 11 confirmed cases and 340 contacts under follow-up, according to the ministry.

The WHO warned that weak surveillance and laboratory capacity are hampering the response, noting that the GeneXpert diagnostic platform widely used during previous Ebola outbreaks can’t detect the Bundibugyo strain. Virus-specific PCR kits are also in limited supply, medical aid group Médecins Sans Frontières said this week.

Countries should rapidly expand laboratory testing, contact tracing and community outreach while negotiating “security corridors” to allow responders to safely reach affected communities, the WHO said in temporary recommendations issued Friday.

The Congolese government reported a positivity rate of almost 46%, suggesting many infections may still be going undetected.

Conflict Zone

The outbreak is unfolding in one of the world’s most volatile regions, where armed groups control large areas, roads are poor and millions of people move between mining camps, towns and neighboring countries. An alliance that includes the Rwanda-backed M23 rebels announced its own Ebola response structure Friday in territory under its control, urging communities to cooperate with health workers and avoid politicizing the outbreak.

The risk inside Congo is now considered “very high,” while neighboring countries face a “high” regional threat, the WHO said. Uganda has tightened border controls and suspended passenger transport links with Congo. Rwanda has also tightened screening measures and said Friday most foreign travelers who recently visited Congo will be denied entry, while returning residents will face mandatory quarantine.

The risk to the general public in the EU remains “very low,” though the bloc has begun coordinating laboratory preparedness and traveler guidance through its Health Security Committee, European health authorities said Friday. The US has taken a more restrictive approach, such as temporarily barring some green card holders who recently visited affected areas from reentering the country.

The outbreak has also exposed growing concerns about the fragility of global outbreak-response systems after years of aid cuts and shifting political priorities.

“We are running behind, we are not yet under control,” Anne Ancia, the WHO’s representative in Congo, said this week.

--With assistance from Sonja Wind, Jessica Nix and John Tozzi.

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