Clinical Report: Transmission Patterns, Infectiousness, and Viral Longevity in Bundibugyo Virus Disease

Background

Bundibugyo virus disease (BVD) is a severe hemorrhagic fever caused by Bundibugyo virus (BDBV), first identified during Uganda’s 2007–2008 outbreak. Only two outbreaks had been reported before the ongoing 2026 outbreak, leaving limited BDBV-specific evidence on transmission, infectiousness, viral persistence, and survivor management.

Data Highlights

• Incubation period: The average interval from contact to clinical onset was 6.3 days during the 2007–2008 Uganda outbreak.

• Burial-related exposure: Direct contact with deceased persons during burial-related activities was associated with increased infection risk (adjusted odds ratio, 3.83; 95% CI, 1.78–8.23).

• Previous case fatality rates: Approximately 30% to 50%.

• Ongoing outbreak: As of June 6, 2026, the Democratic Republic of the Congo had reported 515 laboratory-confirmed cases and 91 confirmed deaths, corresponding to a case fatality rate of 17.7%. This estimate required cautious interpretation because the outbreak was ongoing.

Key Findings

• BDBV transmission occurs primarily through direct contact with the blood or body fluids of symptomatic or deceased individuals.

• Prolonged transmission chains have occurred in household and healthcare settings.

• Burial-related contact with deceased individuals represents a significant risk factor for infection.

• No human cases of presymptomatic BDBV transmission have been documented, although limited evidence prevents this possibility from being definitively excluded.

• Healthcare settings carry substantial transmission risk when adequate personal protective equipment and infection-control measures are not used.

Clinical Implications

Rigorous infection prevention and control measures, appropriate personal protective equipment, safe burial practices, symptom-based surveillance, contact monitoring, and prompt isolation of symptomatic individuals are central to outbreak control. Survivor guidance remains largely extrapolated from evidence involving other orthoebolaviruses because BDBV-specific evidence on viral persistence and post-recovery transmission is unavailable.

Conclusion

The ongoing outbreak underscores the need for prospective epidemiological, clinical, and laboratory investigations, including longitudinal survivor follow-up, to better characterize BDBV transmission, viral persistence, and the determinants of recrudescence and to strengthen species-specific public health recommendations.

Related Resources & Content

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