 This isolation, together with the isolation of infectious RAVV, strongly suggests that Old World fruit bats are involved in the natural maintenance of marburgviruses.Further studies are necessary to establish whether Egyptian rousettes are the actual hosts of MARV and RAVV or whether they get infected via contact with another animal and therefore serve only as intermediate hosts.In 2012 the first experimental infection study of "Rousettus aegyptiacus" with MARV provided further insight into the possible involvement of these bats in MARV ecology.