Re-emerging Marburg virus disease in Africa: spillover ecology, geographic expansion, and surveillance vulnerabilities.

Marburg virus disease (MVD) is re-emerging across Africa as a high-consequence zoonosis shaped by expanding ecological suitability, repeated spillover, and uneven surveillance capacity. This review synthesizes current evidence on the ecological, epidemiological, and operational determinants of contemporary Marburg virus (MARV) emergence. We conceptualize MVD as an ecological-emergence system produced by interactions among reservoir-host biology, environmental change, human exposure, health-system readiness, and mobility, rather than as a series of isolated outbreaks. Recent detections in multiple African regions indicate wider enzootic circulation than previously recognized and support repeated, reservoir-associated introductions from distributed ecological foci. Spillover risk is heightened where mining, land-use change, agricultural encroachment, settlement growth, climate-sensitive habitat disruption, and population movement increase contact with Egyptian rousette bats (Rousettus aegyptiacus) and contaminated roost environments. Following primary spillover, diagnostic delays, fragmented surveillance, limited laboratory decentralization, healthcare-associated transmission, and mobility-linked exposure can enable outbreak amplification and delayed recognition. Serological findings further suggest possible "shadow epidemiology," with unrecognized or mild MARV infections occurring outside confirmed outbreak chains. Critical preparedness gaps persist in ecological risk mapping, longitudinal reservoir surveillance, decentralized molecular diagnostics, genomic sequencing, data integration, and cross-border early warning. Future preparedness should move beyond reactive containment toward integrated One Health approach combining predictive ecological surveillance, rapid community-level detection, real-time genomics, infection prevention, risk communication, and regional coordination to identify spillover early and prevent human transmission.