Arenaviral haemorrhagic fever

Arenaviral haemorrhagic fevers are a group of severe human illnesses caused by at least eight arenaviruses that produce clinical disease, including the haemorrhagic fever syndromes attributed to Guanarito, Junin, Lassa, Lujo, Machupo, Sabia, and Whitewater Arroyo viruses ^[2]. The causative agents are bi- or trisegmented ambisense RNA viruses belonging to the family Arenaviridae, named for the grainy ribosomal particles visible in cross-section ^[2].

The classic clinical picture begins with an insidious onset of influenza-like symptoms, followed in severe cases by a generalised bleeding diathesis, encephalopathy, and death ^[1]. Argentine haemorrhagic fever is a severe illness with haemorrhagic and neurological manifestations and a case fatality of fifteen to thirty percent ^[2]. Aseptic meningitis, an inflammatory condition affecting the brain and spinal cord, has been described in association with the lymphocytic choriomeningitis virus ^[2].

Lassa, Junin, and Machupo viruses are the three arenaviruses that cause severe haemorrhagic disease in humans, with each producing a distinct geographic pattern of disease corresponding to Lassa fever, Argentine haemorrhagic fever, and Bolivian haemorrhagic fever ^[1]. These diseases are a source of considerable economic hardship in endemic areas and remain a worldwide concern for public-health officials ^[1]. A novel arenavirus species, Lujo virus, has been identified in association with five patients exhibiting viral haemorrhagic fever in South Africa, originating near Lusaka, Zambia, and resulting in four fatalities among the five infected ^[2].

Arenaviruses primarily infect rodents and only occasionally humans, and because of this epidemiological association with rodent hosts, some arenaviruses are designated as roboviruses ^[2]. International travel to and from endemic regions has been implicated in the spread of these viruses, leading to the importation of Lassa fever into non-endemic metropolitan areas worldwide ^[2].

No licensed vaccine is currently available for arenavirus infections, which places these pathogens among the most neglected virus groups ^[2]. The only licensed drug for treatment is the nucleoside analogue ribavirin, which reduces morbidity and mortality in infections such as LASV and JUNV when taken in the early stages of disease, although its use is complicated by significant toxicities and mixed success in severe cases ^[2].

1. 1Cummins D et al. Arenaviral haemorrhagic fevers. Blood Rev. 1991 Sep. PMID: 1777745. doi: 10.1016/0268-960x(91)90029-c.PubMed: https://pubmed.ncbi.nlm.nih.gov/1777745/
2. 2Wikipedia contributors. Arenavirus - Wikipedia [Internet]. Wikipedia. cited 3 Sept 2026.Available from: https://en.wikipedia.org/wiki/Arenavirus