Bunyaviruses

Bunyaviruses are enveloped, negative-sense RNA viruses with segmented genomes belonging to the order Bunyavirales. Their genomes have three segments—small (S), medium (M), and large (L). The L segment encodes the RNA-dependent RNA polymerase; the M segment encodes a glycoprotein precursor cleaved into Gn and Gc; the S segment encodes the nucleocapsid protein and, in some members, a nonstructural protein. Virions mature in intracellular membranes and bud into the Golgi before being released from the cell.

Taxonomically, bunyaviruses are divided into several families within Bunyavirales, including Hantaviridae, Peribunyaviridae, Phenuiviridae, and Nairoviridae. Many members are transmitted by arthropods—mosquitoes, ticks, or sandflies—and a number of viruses are notable human pathogens. Hantaviruses are typically rodent-borne and can cause hemorrhagic fever with renal syndrome or hantavirus pulmonary syndrome. Other significant viruses include Rift Valley fever virus (Phenuiviridae) and Crimean-Congo hemorrhagic fever virus (Nairoviridae).

Clinical presentation ranges from mild febrile illness to severe hemorrhagic fevers and encephalitis. Diagnosis relies on serology, nucleic acid testing, or virus isolation in specialized laboratories. There are limited vaccines for bunyaviruses, and public health measures emphasize vector and reservoir control, surveillance, and protective practices for at-risk populations. Ongoing research addresses replication strategies, host range, and antiviral targets.