Ebola outbreak expands in eastern Congo as contact tracing deteriorates amid attacks on burial teams

Ebola has reached a health zone more than 160km from the mining town where Democratic Republic of Congo’s outbreak is believed to have begun, as responders track fewer than 40 per cent of known contacts in the epidemic’s hardest-hit province.

Health officials in Ituri province, which accounts for almost 94 per cent of confirmed infections, were actively monitoring only 39.3 per cent of identified contacts, the country’s National Institute of Public Health said in a report on June 2.

The newly affected health zone of Mambasa lies south-west of the town of Mongbwalu, considered the outbreak’s point of origin, bringing the total number of affected health zones nationwide to 24.

The outbreak – caused by the rare Bundibugyo virus – has become one of the most complex Ebola epidemics in recent years, spreading through a conflict-affected region where insecurity, population movements and distrust of authorities are undermining efforts to identify contacts and isolate cases.

At the same time, health officials are trying to make sense of rapidly changing surveillance data.

More than 4,000 contacts are now under follow-up across the three affected provinces, though fewer than half were reached by surveillance teams, according to the report.

Neighbouring Uganda also confirmed six new cases on June 2, bringing its total to 15 infections, including one death.

Testing gains

Responders in Congo cleared a laboratory backlog that had built up in recent days, analysing all 76 samples collected on June 1. Almost a third tested positive for Ebola.

Congo has now recorded 344 confirmed infections and 60 confirmed Ebola deaths, according to the report.

The death toll rose from 48 reported on June 1 after officials updated figures in North Kivu province, where delays in treatment, community deaths and patients fleeing care have contributed to unusually high mortality. 

Twenty-three new confirmed cases were reported on June 1 alone, including 11 in Mongbwalu and six in Bunia, Ituri’s capital.

“The escape of four confirmed cases – one in Ituri and three in North Kivu – constitutes a major risk of community transmission and ongoing spread of the epidemic,” the report said. 

Burial attacks

Community resistance remains a major obstacle to containment. Red Cross teams carrying out safe burials were attacked and beaten at a cemetery, the report said, while authorities continued to encounter resistance to contact tracing in Bunia and Nizi, a mining town about 24km north of the city.

Health officials also documented persistent rumours that traditional healers possess plant-based cures for Ebola and warned that some communities fear other vaccination campaigns could be mistaken for efforts to spread the virus.

While officials said preliminary data suggest community transmission may be declining, they cautioned that the figures remain incomplete. 

Separately, licensed Ebola vaccines may generate partial immune responses against the Bundibugyo strain, according to a preprint released last week.

Detectable cross-reactive antibodies against Bundibugyo Ebola were found in samples from a large West African vaccine trial, though at substantially lower levels than against the Zaire strain targeted by the shots, researchers at the Vaccine Research Institute in Paris reported. The findings have not yet been peer reviewed. BLOOMBERG