Bunyavirus & Arenavirus Flashcards
Bunyaviridae Group
SUPERGROUP! includes 200+ enveloped segmented ssRNA
most are arboviruses (arthropod)
Bunya Structure
spherical 90-120nm
envelope has 2 proteins G1 &G2
has 3 ssRNA
Bunya Pathogenesis
Viremia, secondary viremia, and target sites such as CNS, Liver, Kidney, vascular endothelium
Induce type 1 interferons
Bunya Symptoms
Usually mild nonspecific febrile, flulike, viremia related illness. fever ~ 3 days
Encephalitis illnesses
~1 week incubation, fever, headache, lethargy, vomiting,
Seizures, meningitis, <1% death.
Hemorrhagic fevers (rift valley fever)
Hantavirus: pulmonary syndrome. resp failure.
Bunya Diagnosis
RT-PCR on viral RNA
ELISA may detect antigen in clinical specimens with intense viremia
Bunya Control
no specific therapy.
kill mosquitos and rats(hantavirus)
Arenaviruses include:
Lymphocyte choriomeningitis(LCMV) Hemorrhagic fever viruses: Lassa, Junin, Machupo.
Arena structure
enveloped virion, 2 circular ambi-ssRNA
Arena Pathogenesis
10-14 days
infect macrophages, induce cytokine + interferon. cell and vascular damage.
T cell immunopathies
Arena Epidemiology
Africa + South America
zoonosis via rodents
infect humans through: inhalation of aersols, contaminated food, fomites. (not usually bites)
Arena LCMV symptoms
Febrile + flulike myalgia
10% progress to CNS
perivascular mononuclear infiltrates
Arena Lassa and other hemorrhagic fevers symptoms
Fever(duh), coagulopathy, petechiae, liver and spleen necrosis. hemorrhage and shock. occasional cardiac and liver damage. death in 50%
Diagnosis
RT-PCR for viral genome.
too dangerous for isolation
level3 for LCM
level 4 for Lassa + others
Treatment
Ribavirin (of course) supportive therapy (so nothing really) don't touch rats.
Immune response
requires CMI but antibody can help viremic spread.