IRD researchers with their colleagues at the Centre International de Recherches Médicales de Franceville (CIRMF, international medical research center of Franceville) in Gabon and at the Centers for Disease Control and Prevention (CDC) in Atlanta, USA, have found that the Egyptian fruit bat (Roussettus aegyptiacus), a migratory fruit bat, is a reservoir of the Marburg virus, an infectious agent belonging to the same family (Filoviridae) as the notorious Ebola virus. The virus, which was discovered in the late sixties, was limited to East Africa at first. In 2000, and later in 2005, it was to blame for large scale epidemics in the Democratic Republic of Congo and then in Angola. Similar to its close relative, the Marburg virus causes violent hemorrhagic fevers in the infected victims.
The scientists examined different specimens belonging to a dozen species of bats, which had been captured during trapping campaigns in 2005 and 2006. They discovered Marburg virus antibodies in the serum of one bat species, the Egyptian fruit bat. The migration area of the fruit bat comprises the entire part of the African continent located south of the Tropic of Cancer. The search for fragments of the viral genome in 283 specimens of Roussettus aegyptiacus showed that the liver and spleen of four specimens contained RNA sequences belonging to three different virus genes. The serum of three out of the four specimens also contained antibodies special to the Marburg virus. The simultaneous presence of special antibodies and viral RNA fragments strongly points to the bat species as a virus carrier that does not develop the symptoms, suggesting that the Egyptian fruit bat is a natural reservoir for the Marburg virus.
The research findings should provide a clearer delimitation of the geographic areas that are potentially threatened by the Marburg virus: the area should be broadened to include West Africa that is a major migratory region for this bat species. The identification of the natural viral reservoir should help develop sanitary measures and prevention campaigns addressed to the local population, with a view to lowering the infectious potential of future hemorrhagic fever outbreaks.
IRD/Gabon - Research Unit on Disease Emergence Conditions and Territories: spatiotemporal dynamics of the emergence, evolution, dissemination/reduction of diseases, resistance and host premunition - Eric Leroy - email: Eric.Leroy@ird.fr
