Chapare mammarenavirus or Chapare virus is a virus from the family Arenaviridae which causes a hemorrhagic fever in humans known as Chapare hemorrhagic fever. It was first described after an outbreak of a novel zoonotic mammarenavirus infection occurred in the village of Samuzabeti, Chapare Province, Bolivia, in January 2003. A small number of people were infected and one person died.In 2019, nine people became infected with the virus in the La Paz regional area, four of whom died. Nosocomial and human-to-human transmission of the virus occurred in at least three of the cases which resulted in the death of a medical intern and a gastroenterologist. Like other members of the Arenavirus family, the specific zoonotic reservoir and primary transmission vector is suspected to be a rodent, probably the small-eared pygmy rice rat. Virology
The Chapare virus is an enveloped virus with a bi-segmented single-stranded ambisense RNA genome. The two RNA segments are denoted Small (S) and Large (L). It belongs to the New World Clade B lineage of mammarenaviruses and is most closely related to the Sabia virus. Symptoms
After an incubation period of around 9–19 days, initial symptoms include fever, malaise, headache, myalgia, back pain, dizziness, nausea, vomiting and diarrhoea. The disease often progresses to include hemorrhagic and neurological symptoms, such as gingival hemorrhage, anaemia, leukopaenia, confusion, seizures, echymoses, bleeding from mucous membranes, hemorrhagic shock and multi-organ failure.Chapare virus RNA was detected in the blood, urine, conjunctiva, semen and in broncho-alveolar and nasopharyngeal samples of the infected patients.
Venezuelan hemorrhagic fever (VHF) is a zoonotic human illness first identified in 1989. The disease is most prevalent in several rural areas of central Venezuela and is caused by Guanarito mammarenavirus (GTOV) which belongs to the Arenaviridae family. The short-tailed cane mouse (Zygodontomys brevicauda) is the main host for GTOV  which is spread mostly by inhalation of aerosolized droplets of saliva, respiratory secretions, urine, or blood from infected rodents. Person-to-person spread is possible, but uncommon. Presentation
VHF has many similarities to Lassa fever and to the arenavirus hemorrhagic fevers that occur in Argentina and Bolivia. It causes fever and malaise followed by hemorrhagic manifestations and convulsions. Some presentations of the virus are also characterized by vascular damage, bleeding diathesis, fever, and multiple organ involvement. Clinical diagnosis of VHF has proven to be difficult based on the nonspecific symptoms. The disease is fatal in 30% of cases and is endemic to Portuguesa state and Barinas state in Venezuela. Treatment and prevention for the VHF virus are limited and there are currently no licensed vaccines available that can act to prevent the disease. However, once infected, ribavirin, an anti-viral drug given intravenously, is one way to treat VHF. Virus
Arenaviruses are enveloped, single-stranded, bisegmented RNA viruses with antisense genomes. Based on their antigenic properties, arenaviruses have been classified into two major groups: the Old World arenaviruses, and the New World arenaviruses. Old World arenaviruses include lymphocytic choriomeningitis virus and Lassa virus.