Marburg Hemorrhagic Fever

Marburg hemorrhagic fever (MHF) is a severe illness caused by Marburg virus, a member of the Filoviridae family. MHF was first described in 1967 during outbreaks in Germany and the former Yugoslavia that were linked to monkeys imported from Uganda. Since then, only a few sporadic cases in East Africa and southern Africa and one laboratory infection have been identified. Serosurveys for Marburg antibodies in the general population generally have shown prevalences of <2%, indicating it to be a rare and highly lethal disease.

The largest outbreak of MHF recorded to date began in late 1998 in northeastern Democratic Republic of the Congo (DRC). Although the remoteness of the area and the civil war in eastern DRC delayed access and evaluation, in May 1999 a team of international investigators identified 73 cases (8 laboratory-confirmed and 65 suspected cases retrospectively identified). Follow-up surveillance subsequently identified >150 cases through December 2000.

The natural reservoir for Marburg virus remains unknown, although it is presumed to be of zoonotic origin. Primary transmission of the virus from the natural reservoir appears to occur only in sub-Saharan Africa and is sometimes followed by secondary person-to-person transmission in both community and nosocomial settings. Because of the disease's rarity and lethality, risk factors for transmission of Marburg virus have not been extensively investigated. We therefore performed two antibody surveys in the wake of the 1998-99 outbreak in DRC to explore risk factors for Marburg virus exposure and transmission. One antibody survey was a cross-sectional study of the general village populations; the other was a focused investigation of healthcare workers (HCWs).