arenavirus report
DESCRIPTION
Arenavirus ReportTRANSCRIPT
ARENAVIRUSESGrace G. Doromal MLS III – A
ARENAVIRUS
CLASSIFICATION Family : Arenaviridae Genus: Arenavirus Subgroup: A) LCM-LASV Complex (Old World
Arenaviruses) B) Tacaribe Complex (New World
Arenaviruses)
MORPHOLOGY Pleomorphic, enveloped viruses with large,
club-shaped peplomers, ranging from 50 – 300 nm in diameter
Genome Double-segmented, circular, single- stranded
RNA that is negative sense and ambisense and is 10- 14 kb in total size
Rodent-borne pathogens Important cause of viral hemorrhagic fever Host cell ribosomes present in the viral
particles are responsible for the “sandy” appearance under the electron microscope
ARENAVIRUS
REPLICATION
REPLICATION
Virus attaches to receptor of the membrane of the host cell and is endocytosed into vesicles
Fusion and release of virion contents in the cytoplasm
Viral mRNAs are capped in the cytoplasm Sequential transcription and translation
occurs Replication starts when enough
nucleoprotein is present to encapsidate neo-synthesized genomes
The ribonucleocapsid interacts with the Z-protein
REPLICATION The virus buds from the plasma membrane,
incorporating host lipids into the virus membrane.
Host cells remain intact. Virus is released from host cell by budding through the cell membrane and gain an envelope. Virus is released from host cell without causing death.
PATHOGENESIS Old World Virus
Lassa Fever Virus Lymphocytic Choriomeningitidis Virus
New World Virus South American Hemorrhagic Fevers
Junin Hemorrhagic Fever Virus Machupo Hemorrhagic Fever Virus Guanarito virus Sabia virus
LASSA FEVER Highly virulent with mortality rate of about 15
% for patients hospitalized with Lassa fever Incubation period: 1-3 weeks from time of
exposure House rat ( Mastomys natalensis ) is the
principal rodent reservoir of Lassa virus The virus can be transmitted through direct
contact with the mouse droppings It may also spread through person-to-person
when an individual comes into contact with the virus in the blood, tissue, secretions or excretions of an individual with the Lassa fever
LASSA FEVERSigns and Symptoms
General weakness and malaise, high fever Sore throat, headache, back, chest, side or
abdominal pain, conjunctivitis, nausea and vomiting, diarrhea, cough
Death
LASSA FEVER
LYMPHOCYTIC CHORIOMENINGITIS Its vector is the wild house mouse Mus
musculus LCM is occasionally transmitted to humans
via mouse droppings. It can be transmitted from mother to fetus.
Incubation period is usually1 -2 weeks, and the illness lasts for 1 – 3 weeks
LCM in humans is an acute disease manifested by aseptic meningitis or a mild systemic influenza-like illness.
LYMPHOCYTIC CHORIOMENINGITIS Signs and Symptoms
fever, stiff neck, malaise, anorexia (lack of appetite), muscle aches, headache, nausea, and vomiting. Symptoms occur 1–2 weeks after exposure.
SOUTH AMERICAN HEMORRHAGIC FEVER Junin Hemorrhagic Fever
Argentine Hemorrhagic Fever Reservoir rodent: Calomys musculinus Human exposure to Junin virus is believed to occur
mainly through inhalation of aerosolized body fluids (blood, saliva) or excretions (urine, faeces) of infected rodents, typically during agricultural. Transmission can also occur via contact of skin lesions to infected rodent secretions and/or excretions.
Incubation Period: Usually 6 to 14 days, but in extreme cases it can range from 5 to 21 days
Transmission through human-to-human is rare; however, nosocomial outbreaks can occur via spread from highly viraemic patients
SOUTH AMERICAN HEMORRHAGIC FEVER Machupo Hemorrhagic Fever
Bolivian Hemorrhagic Fever Reservoir rodent: Calomys callosus Infected animals are asymptomatic and shed the
virus in their excreta, thereby infecting humans. The virus is spread to humans through aerosolized excreta of the rodent, it could be food-borne, or direct contact with the virus particles
The infection has slow onset with fever, malaise, headache and muscular pains. Petechiae on the upper body and bleeding from the nose and gums are observed
SOUTH AMERICAN HEMORRHAGIC FEVER Guanarito Virus
Venezuelan Hemorrhagic Fever Reservoir rodent: Zygodontomys brevicauda Mortality rate of about 33% The virus is spread mostly by inhalation of
aerosolized droplets of saliva, respiratory scretions, urine, or blood from infected rodents
It causes fever and malaise followed by hemorrhagic manifestations ( bleeding ) and convulsions
LABORATORY DIAGNOSIS Cell Culture
Vero Cells Immunohistochemistry
Detect viral antigens in tissues Reverse Transcription- Polymerase Chain
Reaction Detect viral sequences
Serologic Test ELISA IFA
Detect IgM and IgG antibodies