Chapare virus is a New World arenavirus that causes Chapare hemorrhagic fever in Bolivia. The virus has an enveloped, bi‑segmented negative‑sense RNA genome and is thought to be maintained in small rodents such as Oligoryzomys microtis.
Explanation
Chapare virus belongs to the Mammarenavirus genus of the Arenaviridae family. Its virions are pleomorphic, enveloped particles about 50–300 nm in diameter containing two single‑stranded RNA segments. The small segment encodes the nucleoprotein and glycoprotein precursor, and the large segment encodes the viral RNA polymerase and a zinc‑binding protein; both use an ambisense coding strategy. The virus was first identified in 2003 during an outbreak of severe hemorrhagic illness near the Chapare region of Bolivia. Genetic studies showed that it is distinct from other arenaviruses but closely related to Machupo virus. The natural reservoir is not fully confirmed, though Oligoryzomys microtis and related Cricetidae rodents are suspected. Infection likely occurs through contact with rodent excreta or contaminated materials. Clinical presentation resembles other New World hemorrhagic fevers: fever, vomiting, bleeding gums, petechiae, abdominal pain and neurological signs. Case fatality rates reported in documented outbreaks have been high, and there are no specific antiviral treatments or vaccines.
Outbreaks and person‑to‑person transmission
After the initial identification in 2003, Chapare virus reemerged in 2019 when a cluster of cases occurred in La Paz and caused fatal infections among patients and healthcare workers. Investigation by Bolivian and U.S. health authorities confirmed human‑to‑human transmission via contact with body fluids, underscoring the need for strict infection‑control precautions. Public health responses have focused on educating communities about rodent exposure risks and strengthening surveillance to detect cases early. Research continues to elucidate the virus’s ecology, reservoir host and geographic distribution. Chapare virus is a rare but highly pathogenic arenavirus endemic to Bolivia. Awareness of its rodent-linked transmission and the potential for person‑to‑person spread in healthcare settings is essential for prevention and control. Related Terms: Machupo virus, Sabia virus, Guanarito virus, Junin virus, Lujo virus