Arenavirus Infection

  Arenavirus

The Arenaviridae are a family of viruses whose members are generally associated with rodent-transmitted diseases in humans. Each virus usually is associated with a particular rodent host species in which it is maintained. Arenavirus infections are relatively common in humans in some areas of the world and can cause severe illnesses. The virus particles are spherical and have an average diameter of 110-130 nanometers.  Their genome, or genetic material, is composed of RNA only, and while their replication strategy is not completely understood, we know that new viral particles, called virions, are created by budding from the surface of their hosts' cells.

 Arenavirus history: The first Arenavirus, Lymphocytic choriomeningitis virus (LCMV), was isolated in 1933 during a study of an epidemic of St. Louis encephalitis. Although not the cause of the outbreak, LCMV was found to be a cause of aseptic (nonbacterial) meningitis. By the 1960s, several similar viruses had been discovered and they were classified into the new family Arenaviridae. Since Tacaribe virus was found in 1956, new Arenavirus have been discovered on the average of every one to three years. 

 Spreading Arenavirus infections: The rodent hosts of Arenavirus species are chronically infected with virus; however, the viruses do not appear to cause obvious illness in them. Some Arenavirus types appear to be passed from mother rodents to their offspring during pregnancy, and thus remain in the rodent population generation after generation. Most infections are transmitted among adult rodents, likely via fighting and inflicting bites. Only a portion of the rodents in each host species is infected at any one time, and in many cases only in a limited portion of the host's geographical range. Viruses are shed into the environment in the urine or droppings of the infected hosts.