4. Machupo virus
Machupo virus is a type of virus that belongs to the family Arenaviridae and is the causative
agent of Bolivian hemorrhagic fever. It is primarily transmitted to humans through contact
with infected rodents, such as the vesper mouse (Calomys callosus), which serves as the
natural reservoir for the virus.
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5. Bolivian haemorrhagic fever (BHF), also known as black typhus or Ordog Fever, is
a haemorrhagic fever and zoonotic infectious disease originating in Bolivia after infection
by Machupo mammarenavirus.
First encounter-1962, in the Bolivian village of San Joaquín, hence the name "Bolivian" Hemorrhagic
Fever.
First identification- 1963, as an ambisense RNA virus by a research group led by Karl Johnson.
Disease
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6. Structure and features of virion
It is a spherical and pleomorphic virus.
Diameter ranging from 50 to 300 nm in length (average of 120nm).
It has a single-stranded and bi-segmented RNA genome.
The virus contains ribosomes that give it a sandy appearance under electron microscopy.
The virus is enclosed in a dense, lipid-containing envelope with 8-10 nm long club-
shaped projections around the outside.
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7. Transmission
The vector is the large vesper mouse (Calomys callosus), a rodent indigenous to northern Bolivia. Infected animals are
asymptomatic and shed the virus in excreta, thereby infecting humans. Evidence of person-to-person transmission of
BHF exists but is believed to be rare.
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8. Replication and Life cycle
Attachment and Entry : Attaches to host
cells- interactions-viral glycoprotein and cell
surface receptors. virus internalized by
endocytosis.
Uncoating : The viral envelope fuses-the
endosomal membrane-releasing the viral
ribonucleoprotein (RNP).
Replication : Viral RNA genome- copies of
the viral genome.
Transcription and Translation : The viral
RNA genome- (RdRp) into- mRNA- viral
proteins.
Assembly and release : New viral particles
are assembled by- packaging - Mature viral
particles - released from infected cells. 8
9. Symptoms
• Fever
• Headache
• Muscle aches
• Weakness and fatigue
• Dizziness
• Nausea and vomiting
• Diarrhea
• Abdominal pain
• Chest pain
• Skin rash
• Bleeding from the eye, mouth, nose, and gums
• Bruising
• Shock
• Organ failure
In severe cases, the disease can progress rapidly and lead to multi-organ
failure, shock, and death.
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11. Treatment
Antiviral therapy (Ribavirin)
⬡ Acts via lethal mutagenesis
Non-specific control- fluid replacement, blood transfusion.
Convalescent plasma therapy- collection of blood portion who has recovered from
BHF, that will contain antibodies.
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12. Prevention and Control
Avoid contact with infected individuals or animals.
Hand hygiene, disinfection of surfaces and equipment, and isolation of
infected individuals.
Vaccination.
Individuals traveling to areas where Bolivian hemorrhagic fever is endemic
should take precautions to avoid contact with infected animals or people and
follow general travel health recommendations.
Early recognition and treatment of Bolivian hemorrhagic fever can improve
outcomes.
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13. References
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ICTV
"ICTV Taxonomy history: Machupo
mammarenavirus". International
Committee on Taxonomy of Viruses
(ICTV). Retrieved 28 January 2019.
Webb PA et.al.,
Webb PA, Johnson KM, Mackenzie
RB, Kuns ML (July 1967). "Some
characteristics of Machupo virus,
causative agent of Bolivian
haemorrhagic fever". Am. J. Trop.
Med. Hyg. 16 (4): 531–8.
CFSPH
Center for Food Security &
Public Health and Institute for
International Cooperation in
Animal Biologics, Iowa State
University: Viral Hemorrhagic
Fevers Caused by
Arenaviruses.
Anguilar et.al.,
Aguilar PV, Carmago W, Vargas J,
Guevara C, Roca Y, Felices V, et
al. Reemergence of Bolivian
hemorrhagic fever, 2007–2008
[letter]. Emerg Infect Dis [serial on
the Internet] 2009 Sep.
