Junin virus or Junín virus (JUNV), is an

arenavirus An arenavirus is a bi- or trisegmented ambisense RNA virus that is a member of the family ''Arenaviridae''. These viruses infect rodents and occasionally humans. A class of novel, highly divergent arenaviruses, properly known as reptarenavirus ...

in the ''

Mammarenavirus ''Mammarenavirus'' is a genus of viruses in the family ''Arenaviridae''. The name is a portmanteau of mammal and the former name ''Arenavirus'', and differentiates it from the reptile-associated ''Reptarenavirus''. ''Arenavirus'' comes from the ...

'' genus that causes

Argentine hemorrhagic fever Argentine hemorrhagic fever (AHF) or O'Higgins disease, also known in Argentina as mal de los rastrojos (stubble disease) is a hemorrhagic fever and zoonotic infectious disease occurring in Argentina. It is caused by the Junín virus (an arenavi ...

(AHF). The virus took its original name from the city of Junín, around which the first cases of infection were reported, in 1958.

Virology

Structure

Junín virus is a negative sense ssRNA enveloped virion with a variable diameter between 50 and 300 nm. The surface of the particle encompasses a layer of T-shaped

glycoprotein Glycoproteins are proteins which contain oligosaccharide (sugar) chains covalently attached to amino acid side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known a ...

s, each extending up to 10 nm outwards from the envelope, which are important in mediating attachment and entry into host cells.

Genome

The Junín virus genome is composed of two single-stranded RNA molecules, each encoding two different genes in an

ambisense In molecular biology and genetics, the sense of a nucleic acid molecule, particularly of a strand of DNA or RNA, refers to the nature of the roles of the strand and its complement in specifying a sequence of amino acids. Depending on the context, ...

orientation. The two segments are termed 'short (S)' and 'long (L)' owing to their respective lengths. The short segment (around 3400 nucleotides in length) encodes the nucleocapsid protein and the glycoprotein precursor (GPC). The GPC is subsequently cleaved to form two viral glycoproteins, GP1 and GP2, which ultimately form the T-shaped glycoprotein spike which extends outwards from the viral envelope

The long segment (around 7200 nucleotides in length) encodes the viral

polymerase In biochemistry, a polymerase is an enzyme (Enzyme Commission number, EC 2.7.7.6/7/19/48/49) that synthesizes long chains of polymers or nucleic acids. DNA polymerase and RNA polymerase are used to assemble DNA and RNA molecules, respectively, by ...

and a zinc-binding protein. The virus is spread by rodents.

Disease and epidemiology

A member of the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

'', Junín virus characteristically causes

(AHF). AHF leads to severe compromise of the

vascular Vascular can refer to: * blood vessels, the vascular system in animals * vascular tissue Vascular tissue is a complex transporting tissue, formed of more than one cell type, found in vascular plants. The primary components of vascular tissue ...

neurological Neurology (from , "string, nerve" and the suffix -logia, "study of") is the branch of medicine dealing with the diagnosis and treatment of all categories of conditions and disease involving the nervous system, which comprises the brain, the s ...

and

immune In biology, immunity is the state of being insusceptible or resistant to a noxious agent or process, especially a pathogen or infectious disease. Immunity may occur naturally or be produced by prior exposure or immunization. Innate and adaptive ...

systems and has a mortality rate between 20 and 30%. Symptoms of the disease are

conjunctivitis Conjunctivitis, also known as pink eye or Madras eye, is inflammation of the conjunctiva, the thin, clear layer that covers the white surface of the eye and the inner eyelid. It makes the eye appear pink or reddish. Pain, burning, scratchiness ...

purpura Purpura () is a condition of red or purple discolored spots on the skin that do not blanch on applying pressure. The spots are caused by bleeding underneath the skin secondary to platelet disorders, vascular disorders, coagulation disorders, ...

petechiae A petechia (; : petechiae) is a small red or purple spot ( 1 cm in diameter) and purpura (3 to 10 mm in diameter). The term is typically used in the plural (petechiae), since a single petechia is seldom noticed or significant. Causes Physical ...

and occasionally

sepsis Sepsis is a potentially life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage of sepsis is followed by suppression of the immune system. Common signs and s ...

. The symptoms of the disease can be confusing; the condition can be mistaken for a different one, especially during the first week when it can resemble a flu. Since the discovery of Junín virus in 1958, the geographical distribution of the pathogen, although still confined to Argentina, has expanded. At the time of discovery, Junín virus was confined to an area of around 15,000 km². At the beginning of 2000, the region with reported cases grew to around 150,000 km². The natural hosts of Junín virus are rodents, particularly ''Mus musculus'', ''Calomys'' spp. and ''Akodon azarae''. Direct rodent-to-human transmission only takes place when a person makes direct contact with the excrement of an infected rodent; this can occur by ingestion of contaminated food or water, inhalation of particles in urine or direct contact of an open wound with rodent feces.

Potential therapy

A potential novel treatment, the NMT inhibitor, has been shown to completely inhibit JUNV infection in cells based assays.

Prevention and control

An investigational (in the US) vaccine (Candid1) was developed at the US Army Medical Research Institute for Infectious Disease (

USAMRIID The United States Army Medical Research Institute of Infectious Diseases (USAMRIID; ) is the United States Army's main institution and facility for defensive research into countermeasures against biological warfare. It is located on Fort Det ...

) at Ft. Detrick, MD in the 1980s which has shown to be safe, well tolerated and effective in reducing mortality and morbidity due to AHF. The vaccine, which came from an XJ strain of the Junín virus, was continually passaged a total of 44 times in newborn mouse brains, and a total of 19 times along with cloning in FRhL cells. Over 90% of the volunteers in Phase 1 and 2 clinical trials developed antibodies against the Junín virus, and 99% developed an adequate immune response specific for Junín virus. Moreover, a large efficacy study among 6,500 people, where 3,255 individuals were randomly selected to take Candid 1 and 3,245 individuals were randomly selected to take a placebo resulted in 23 cases of Junin-like infections, where 22 out of the 23 cases were from the placebo group. This efficacy study resulted in a 95% vaccine efficacy. Currently, the Candid 1 vaccine, otherwise known as the Junin vaccine, is licensed in Argentina by the regulatory agency of Argentina where Junín virus is endemic to the region. People in laboratories who come in constant contact with Junín virus are also recommended to take the Junin vaccine to prevent transmission.Pittman, Phillip R., and Stanley A. Plotkin. (2013) "41 – Biodefense and Special Pathogen Vaccines." ''Biodefense and Special Pathogen Vaccines - Vaccines (Sixth Edition)''

References

{{DEFAULTSORT:Junin Virus Arenaviridae Rodent-carried diseases Vaccine-preventable diseases