Rodent-Borne Hemorrhagic Fever Viruses: A Special Risk for Mammalogists?

We review two groups of taxonomically unrelated viruses that share similarities in host preference and transmission routes to humans and pose a risk for mammalogists working with rodents. The rodent-borne hemorrhagic fever viruses in the Arenaviridae and Bunyavi-ridae are widely distributed on most continents where rodents occur. Their geographic distribution usually exceeds the distribution of the recognized human diseases they cause and has resulted from either natural coevolutionary events or the dissemination of viral passengers traveling with introduced mammalian hosts. Diseases of humans caused by these agents are among the most severe and most frequently fatal of zoonotic diseases. These viruses show remarkable specialization in the limited number of rodent species in which they naturally occur and frequently establish persistent infections in individual hosts that can result in variable effects on growth, reproduction, and survival of hosts. Our knowledge of these viruses, their hosts and geographical range, and the pathophysiological consequences of infection are incompletely understood and offer a rich area of study for naturalists interested in host-parasite coevolution.