Frontline-worker infections as a marker of infection-prevention stress during the 2026 Bundibugyo virus disease outbreak in the Democratic Republic of the Congo

Objective: To quantify the reported burden, temporal contribution, mortality and health-zone distribution of frontline-worker infections during the 2026 Bundibugyo virus disease (BVD) outbreak in the Democratic Republic of the Congo, and to examine contemporaneous infection-prevention-and-control (IPC) evidence. Methods: We conducted a retrospective longitudinal analysis of DRC situation reports, the INRB-UMIE BDBV2026-Data repository, and WHO outbreak updates, per STROBE principles. National health-worker snapshots were reconstructed for 10 June-9 August 2026; detailed Ituri Province tables were analysed for 13 July-4 August. Crude case fatality among frontline and other confirmed cases was compared using risk ratios and a stratified Mantel-Haenszel odds ratio. Findings: Nationally, health-worker infections rose from 16/676 confirmed cases (2.4%) on 10 June to 151/3,605 (4.2%) on 30 July, contributing 11.0% of newly accumulated cases in the first three weeks but only 2.2-2.6% thereafter. Reported case fatality was lower among health workers, nationally on 30 July (29.1% versus 44.7%; risk ratio 0.65, 95% CI 0.51-0.84) and in Ituri on 4 August (30.7% versus 42.8%; RR 0.72, 95% CI 0.56-0.92; stratified odds ratio 0.59, 95% CI 0.41-0.85). Burden was spatially concentrated but heterogeneous across health zones. IPC reports documented low facility scorecards, recurrent high-risk exposures, and inconsistent worker denominators. Conclusion: Frontline-worker infections formed a substantial, front-loaded epidemic component and a visible IPC-stress marker, but aggregate data cannot establish occupational incidence or place of acquisition. Lower reported mortality likely reflects earlier recognition or care access rather than lower severity. Standardized worker denominators and linked occupational surveillance should be incorporated into Ebola situation reporting.