The Role of Mortality Surveillance in Case Detection and Response During the 2025 Sudan Virus Disease Outbreak in Uganda.

Abstract

Background: Developing countries like Uganda, face challenges in containing filovirus outbreaks such as Sudan virus disease (SVD). The 2025 Sudan Virus Disease outbreak in Uganda predominantly affected urban and peri-urban areas. To curtail the outbreak, mortality surveillance was integrated into the response strategies. This paper describes how mortality surveillance was implemented, its contribution to case detection and to the triggering of response actions, and the facilitators and barriers to its implementation during this outbreak.

Methods: A retrospective descriptive document review was conducted, analyzing situation reports, meeting minutes, technical briefs, and mortality surveillance summaries generated by the Incident Management Team between the declaration of the outbreak (30 January 2025) and its official end (26 April 2025). We described the implementation processes, the contribution of mortality surveillance to case detection and response, and the facilitators and barriers to its implementation during the 2025 Sudan virus disease (SVD) outbreak.

Results: During the 2025 Sudan Virus Disease outbreak, mortality surveillance was rapidly activated and integrated into active surveillance. Mortality surveillance was conducted systematically involving the following community engagement; death notification; epidemiological investigations; and containment measures such as contact tracing, quarantine, and safe and dignified burials. Mortality surveillance contributed to case detection: 3/14 (21.4%) cases registered during the outbreak were identified through investigations triggered by death alerts. These detections informed public health measures such as contact tracing and quarantine of contacts, which may have contributed to interrupting potential transmission chains. Key facilitators included strong coordination and leadership, the use of digitized data tools, capacity building and community engagement and involvement. Persistent barriers included underreporting from informal settlements and private clinics, logistical delays in sample transportation, and lack of mortality surveillance guidelines during the outbreak.

Conclusion: The 2025 Sudan virus disease outbreak in Uganda demonstrates the potential value of integrating mortality surveillance into outbreak detection and response, particularly in urban and informal settings. Strengthening mortality surveillance systems should be considered a core component of epidemic preparedness and response strategies in low- and middle-income countries facing recurrent filovirus threats.