WHO's Disease Outbreak News 603, published 21 May, recorded 831 total cases (85 confirmed, 746 suspected) and 186 deaths from Bundibugyo Ebola in the Democratic Republic of Congo (DRC)1. That is roughly triple the 246 cases on the books when WHO Director-General Tedros Adhanom Ghebreyesus declared the Public Health Emergency of International Concern (PHEIC) four days earlier, the first such declaration ever made for this Ebola species. Bundibugyo is one of six Ebola virus species, with no licensed vaccine or treatment of its own.
Read the jump with care. Most of the rise is case-finding catching up after the declaration, not the virus accelerating. The outbreak ran undetected in Ituri province for more than four weeks, so surveillance teams are now logging deaths that occurred before anyone was looking, rather than recording a sudden burst of new infections.
The suspected case-fatality rate sits near 24%, with 96% of cases in three Ituri health zones: Mongbwalu, Rwampara and Bunia2. The figure that should worry a reader more is the 21% contact follow-up rate: insecurity keeps tracing teams away from most named contacts3. A 24% fatality rate measured against a 21% tracing rate is a partial count of a poorly observed outbreak, not a settled verdict on how lethal it is.
The sharpest signal is at Mongbwalu General Referral Hospital, where four healthcare workers died in four days4. Clustered staff deaths point to a breakdown in infection prevention and control, the gowning, isolation and barrier-nursing routines that stop Ebola spreading inside the hospitals treating it. Hospital amplification of this kind turned the 2014 West Africa outbreak from regional to catastrophic; when the people running isolation wards begin dying, the wards stop being safe.
