Arenavirus is a genus of virus that infects rodents and occasionally humans. At least eight Arenaviruses are known to cause human disease. The diseases derived from Arenaviruses range in severity. Aseptic meningitis, a severe human disease that causes inflammation covering the brain and spinal cord, can arise from the Lymphocytic choriomeningitis virus (LCMV) infection. Hemorrhagic fever syndromes are derived from infections such Guanarito virus (GTOV), Junin virus (JUNV), Lassa virus (LASV) causing Lassa fever, Machupo virus (MACV), Sabia virus (SABV), or Whitewater Arroyo virus (WWAV). Arenaviruses are divided into two groups; the Old World or New World. The differences between these groups are distinguished geographically and genetically. Because of the epidemiological association with rodents, some arenaviruses and bunyaviruses are designated as Roboviruses.