Mhr Topic 31: Rotaviruses And Enveloped Rna Viruses

Front 1

Rotavirus (genome, virion structure)

Back 1

Non enveloped, Linear, DS RNA, segmented.
Virion looks like a wheel with spokes.

Front 2

Rotavirus transmission

Back 2

via fecal oral

Front 3

Rotavirus replication

Back 3

1) Enters body through ingestion
2) Viral protectivity is removed by pancreatic proteases allowing it to attach to small bowel
3) Enters epithelial cells, translation and some replication occurs in cytoplasm
4) relication is finished in virions
5) virions leave cell via lysis

Front 4

Rotavirus (disease and mechanism)

Back 4

1) Usually attacks kids under 5. Severe dehydration is main symptom. Symptoms are fever, abdominal pain, vomiting and copious osmotic diarrhea.
2) Virus destroys brush border causing malabsorbtion and loss of secretion of digestive enzymes by epithelium.

Front 5

Rhaboviridae (genome, virion structure)

Back 5

1) SS - Unsegmented RNA.
2) Enveloped, bullet shaped, covered in G proteins.

Front 6

Rhaboviridae replication

Back 6

1) After infection, virus replicates in muscle
2) eventually passes into nerve cells (usually sensory) via G protein binding to Ach receptors.
3) Replication occurs in neuron cytoplasm via viral RNA polymerase.
4) Is passively transferred up nerves, to spinal chord, eventually to brain via Ach receptors.

Front 7

Rhaboviridae Infection

Back 7

Via saliva of animals entering broken skin. Bats are most common.

Front 8

Rhaboviridae Disease and mech

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Rabbies. Asymptomatic until reaches brain. Then headache, fever, behavior changes, loss of muscle coordination, then travels down facial nerves (to things like salivary glands) and now person is contagious. Once in brain, fatal in 2 weeks. Most fatal infectious disease.

Front 9

Rhaboviridae Diagnosis

Back 9

Usually diagnosed via brain biopsy at autopsy (negri bodies). Key symptoms are loss of muscle coordination and hydrophobia (cant drink water).
Problems with diagnosis is disease is rare, people dont always report bites or dont know (bats have small teeth), and early symptoms are non-specific.

Front 10

Rhaboviridae Treatment

Back 10

Wash bite, vaccine, premade antibodies near site of inoculation.

Front 11

Filoviridae (genome and virion structure)

Back 11

SS - RNA. Enveloped, have unique filamentous morphology.

Front 12

Filoviridae Transmission

Back 12

Caused by ebola or marburg viruses Via blood and body fluid contact. Transferred by caring for sick people. Thought to be often transferred by person who slaughters monkeys and gets splashed with blood. Becomes the index case of an epidemic.

Front 13

Filoviridae Disease

Back 13

Caused by ebola or marburg viruses. Cause African tropical hemorrhagic fevers with an extremely high mortality.

Front 14

Bunyaviridae (genome and structure)

Back 14

Enveloped virion with a -SS segmented RNA genome.

Front 15

Bunyaviridae transmission

Back 15

Caused by four corners hantavirus. Usually infects healthy people in rural areas. Transmission via aerosoled rodent excretions.

Front 16

Bunyaviridae Disease

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Hantavirus pulmonary syndrome = Febrile illness, hypotension, pneumonia. High mortality.

Front 17

Arenaviridae genome and structure

Back 17

Enveloped, - RNA with 2 segments.

Front 18

Arenaviridae transmission

Back 18

LCVM - via aerosoled rodent excretions.
Lassa Fever Virus - west africa, can spread via rodent excretions or person to person blood contact.

Front 19

Arenaviridae disease

Back 19

LCVM - Causes viral meningitis. If woman is pregnant, can be very harmful to fetus.
Lassa Flever - flu like illness, 20% will die of shock.