The Ebola outbreak in the northeastern Democratic Republic of Congo is spreading largely undetected, with up to 80% of new cases having no known connection to existing patients, according to a senior World Health Organization official. This situation suggests the true scale of the outbreak could be two to four times larger than currently reported.
This lack of known contact underscores the significant challenges health workers face in containing the epidemic, which has officially infected 1,792 people and caused 625 deaths as of Thursday, according to government data. In the heart of the outbreak in Bunia, Ituri province, WHO Emergencies Director Chikwe Ihekweazu stated that 80% of new confirmed patients are emerging from outside known contact lists.
Ihekweazu noted that in areas with fewer cases, such as North Kivu province, nearly all new infections are being identified through contact tracing, indicating some progress in localized containment efforts. However, the overall picture, based on modeling and positivity rates, points to widespread community transmission since the outbreak was declared in mid-May.
Approximately 90% of all reported cases are concentrated in Ituri province, specifically in the health zones of Bunia, Rwampara, Mongbwalu, and Nyakunde, where transmission remains intense. The virus has also extended its reach beyond this epicenter, spreading to North Kivu province, South Kivu province, and more recently, Tshopo province.
In Bunia, the capital of Ituri with a population of one million, about half of individuals tested for Ebola are positive, a strong indicator of widespread community transmission, Ihekweazu explained. Preliminary findings suggest that the Bundibugyo strain of the Ebola virus may present milder symptoms compared to other strains. This could contribute to reduced perception of risk within affected communities, potentially leading families to care for sick relatives at home before seeking medical attention.
While milder symptoms might improve survival rates for those who eventually reach treatment centers, it also allows infected individuals to remain in the community longer, facilitating further transmission. "The longer patients are outside of care, the more likely they are to transmit this illness," Ihekweazu commented. Community deaths also remain a significant concern; an analysis of the first 400 fatalities revealed that approximately 70% occurred outside of formal treatment centers.
Strengthening surveillance remains the paramount challenge for the ongoing response. In an effort to improve case detection, authorities recently began training 21,000 community health workers to conduct door-to-door visits, identify potential cases, and encourage symptomatic individuals to seek care.