Bunyavirus & Arenavirus

Question 1

Bunyaviridae Group

Answer 1

SUPERGROUP! includes 200+ enveloped segmented ssRNA

most are arboviruses (arthropod)

Question 2

Bunya Structure

Answer 2

spherical 90-120nm
envelope has 2 proteins G1 &G2
has 3 ssRNA

Question 3

Bunya Pathogenesis

Answer 3

Viremia, secondary viremia, and target sites such as CNS, Liver, Kidney, vascular endothelium
Induce type 1 interferons

Question 4

Bunya Symptoms

Answer 4

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.

Question 5

Bunya Diagnosis

Answer 5

RT-PCR on viral RNA

ELISA may detect antigen in clinical specimens with intense viremia

Question 6

Bunya Control

Answer 6

no specific therapy.

kill mosquitos and rats(hantavirus)

Question 7

Arenaviruses include:

Answer 7

Lymphocyte choriomeningitis(LCMV)
Hemorrhagic fever viruses: Lassa, Junin, Machupo.

Question 8

Arena structure

Answer 8

enveloped virion, 2 circular ambi-ssRNA

Question 9

Arena Pathogenesis

Answer 9

10-14 days
infect macrophages, induce cytokine + interferon. cell and vascular damage.
T cell immunopathies

Question 10

Arena Epidemiology

Answer 10

Africa + South America
zoonosis via rodents
infect humans through: inhalation of aersols, contaminated food, fomites. (not usually bites)

Question 11

Arena LCMV symptoms

Answer 11

Febrile + flulike myalgia
10% progress to CNS
perivascular mononuclear infiltrates

Question 12

Arena Lassa and other hemorrhagic fevers symptoms

Answer 12

Fever(duh), coagulopathy, petechiae,
liver and spleen necrosis.
hemorrhage and shock.
occasional cardiac and liver damage. 
death in 50%

Question 13

Diagnosis

Answer 13

RT-PCR for viral genome.
too dangerous for isolation
level3 for LCM
level 4 for Lassa + others

Question 14

Treatment

Answer 14

Ribavirin (of course)
supportive therapy (so nothing really)
don't touch rats.

Question 15

Immune response

Answer 15

requires CMI but antibody can help viremic spread.