The International Rescue Committee, a nonprofit global aid group, posted a warning Monday that the current Ebola outbreak in the Democratic Republic of Congo could have been spreading for three months before any cases were detected.

​In the press release published by IRC on Monday, the group cited “delayed detection and slow contact tracing” as reasons for the virus’s undetected spread. The true scale of infections is likely far higher than that reported by other official sources, according to the group.

​“With only 20% of contacts currently being traced, health authorities are struggling to identify and isolate new chains of transmission,” it states. Because the outbreak went largely undetected for a significant period, multiple chains of transmission were established across communities and provinces in the DRC before it was detected.

Map of current Ebola outbreak (Grace Hagerman/Washington Examiner)

The IRC press release contradicts reports from the World Health Organization, which estimated there were fewer Ebola cases in the DRC than previously thought, with authorities attributing some of the potential Ebola cases to other diseases. Findings from the Centers for Disease Control and Prevention stated that as of June 2, the DRC Ministry of Health reported 344 confirmed cases and 60 confirmed deaths.