Argentine haemorrhagic fever

Argentine haemorrhagic fever (AHF) is an infection with the Junin viruses. Junin viruses belong to the Arenaviridae family and, like other Arenaviridae (e.g. Lassa fever), cause a haemorrhagic fever illness.

The Junin, Machupo, Guanarito and Sabia viruses belong to the New World family of arenaviruses and are found in South America. These arenaviruses are triggers of various hemorrhagic fevers such as:

• Argentine haemorrhagic fever
• Bolivian haemorrhagic fever
• Venezuelan hemorrhagic fever
• Brazilian hemorrhagic fever

Arenaviruses are composed of a lipid envelope and are pleomorphic with an average diameter of 50-300nm. They contain 2 RNA segments, the L- du the S-segment, which contain the information for structural proteins (nucleocapsid protein and glycoproteins) and an enzyme (viral polymerase). In the finished virus, the nucleocapsid is protectively wrapped around the RNA. The glycoproteins G1 and G2 are anchored in the lipid envelope. They serve to absorb and release the L and S segments into the cytoplasm, and are thus essential for recognition and entry into the host cell. Viruses replicate in the cell via a viral polymerase.

Infections with the South American hemorrhagic fever viruses are mainly treated symptomatically. In many patients, light sedation (sedation) and pain treatment with opiates is recommended. Bleeding should be treated by transfusions of platelets and coagulation factors.

Control of the electrolyte and fluid balance, if necessary controlled balancing.

The antiviral drug ribavirin seems to have a positive influence on the outcome of Junin and Machupo virus infections at least.

A commercial immunoglobulin for the therapy of AHF does not yet exist. A vaccine for AHF based on an attenuated virus is in the second clinical trial phase. The vaccine was well tolerated by primates and provided good protection against experimental infection of the animals. First tests with the vaccine on humans in risk areas indicate a fairly good protection against infection with the Junin virus. It is currently being evaluated whether the vaccine against AHF also provides protection against the very similar Machupo virus (Zeitlin L et al. 2016; Zeitlin L et al. 2016).

Animal experiments with the viral static drug favipiravir have been successful (Gowen BB et al. 2017), so that it can be assumed that this drug is also used in humans (see Favipiravir).

The name arenavirus is derived from a characteristic dark granulation (Latin arenosus = sand-like) of the viruses in electron micrographs. These present themselves as ribosomes, which are included when the viruses sprout.

1. Gaudin R et al (2015) Superinfection exclusion is absent during acute Junin virus infection of Vero and A549 cells. Sci Rep 5:15990.
2. Gowen BB et al (2017) Enhanced protection against experimental Junin virus infection through the use of a modified favipiravir loading dose strategy. Antiviral Res 145:131-135.
3. Weissenbacher MC et al (1975) Experimental biology and pathogenesis of Junin virus infection in animals and man. Bull World Health Organ 52(4-6):507-515.
4. Zeitlin L et al (2016) Monoclonal antibody therapy for Junin virus infection. Proc Natl Acad Sci U S A 113:4458-4463.