Discovery and classification of arenaviruses

The prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) was one of the first human pathogenic viruses isolated. In 1933, Armstrong and Lillie obtained a filterable infectious agent from a brain of a patient who died during a St. Louis encephalitis epidemic [1]. In the mid-1930s, Rivers and Scott isolated a virus from cerebrospinal fluid (CSF) of a patient with aseptic meningitis [2], which was later shown to have the same serologic properties as the virus isolated by Armstrong and Lillie and a pathogen causing chronic infections in mouse colonies [3]. By the 1960s, several other viruses had been discovered that shared common morphology with a characteristic sandy (Latin, arenosus) appearance of ribosomes seen in thin sections of virions in electron microscopic images, serology, and biochemical features. These findings led to the establishment of the new virus family Arenaviridae in 1970 [4].

The Arenaviridae are a large group of viruses, which is currently subdivided into two major subgroups, the Old World (OW) arenaviruses and the New World (NW) arenaviruses [5, 6, 7]. The OW lineage contains LCMV endemic in Europe, the Americas, and likely present also in other geographic regions, and the African viruses Lassa (LASV), Mopeia (MOPV), Mobala (MOBV), and Ippy (IPPY). LCMV infections in humans are common, in some cases severe, and are of considerable concern in human pediatric medicine [8, 9, 10]. Fatal LCMV infection has also been recently documented in several transplant patients [11].