Clinical features of Marburg virus disease: a review of all reported patients since 1967.

Background: Marburg virus disease (MVD) is a severe and often fatal illness caused by the Marburg or Ravn virus. Given the remote areas affected and the infrequency of the disease, the MVD presenting syndromes are unclear, and this may limit timely recognition. Methods: We conducted 333 a literature review of published case reports and outbreak investigations from January 1st, 1967 to October 30th, 2024, to describe the prevalence of MVD-associated symptoms and syndromes. Findings: 722 cases of MVD occurred across 18 outbreaks, with detailed clinical data available for 325 cases. Common symptoms include fever, headache, fatigue, and myalgia; gastrointestinal symptoms are also frequently reported. Haemorrhagic symptoms, mainly hematemesis and bloody diarrhoea, are more specific but less frequent. The overall lethality rate is 72% (95% CI: 68.8-75.0%), dropping to 44% (95% CI: 37.1-50.9%) among PCR-confirmed cases. Interpretation: Variability in prevalent symptoms across different outbreaks complicates early recognition. The lower lethality observed in PCR-confirmed cases may reflect earlier access to appropriate care once Marburg virus disease was recognized, as well as potential misclassification of non-MVD febrile illnesses among unconfirmed cases. Funding: This work was supported by the Italian Ministry of Health, Project P3 - Ricerca Corrente Linea1 - Malattie infettive tropicali e neglette: aspetti patogeneteci, immunologici e diagnostici del Ministero della salute-INMI L.Spallanzani I.R.C.C.S.