WHO guidance for mass gathering events attended by individuals from areas with documented Bundibugyo virus detection, May 2026

Overview

This WHO guidance provides updated recommendations for the planning and management of mass gathering events attended by individuals from areas with documented Bundibugyo virus disease (BVD) transmission.

Issued in the context of the 2026 epidemic in the Democratic Republic of the Congo and Uganda, the document replaces the 2014 interim guidance developed for Ebola virus disease outbreaks and reflects changes in virus taxonomy, epidemiology and available medical countermeasures. It outlines the specific characteristics of Bundibugyo virus disease, including transmission patterns, incubation period, clinical presentation and the absence of licensed vaccines or approved therapeutics.

The guidance sets out preparedness and response measures for event organizers and public health authorities before, during and after mass gatherings. It emphasizes the importance of risk assessment, event-based surveillance, screening procedures, referral pathways, infection prevention and control measures, and coordination under the International Health Regulations (2005).

Particular attention is given to early detection, laboratory confirmation through RT-PCR testing, isolation of suspected cases, risk communication and cross-border collaboration for contact tracing. The document also includes operational considerations for participant information, public health messaging and post-event evaluation to support evidence-based management of health risks associated with international gatherings during BVD outbreaks.