Emerging viruses

Question 1

What 2 viruses are members of the Filovirus family and have curved virion structures?

Answer 1

Marburg and Ebola viruses

Question 2

Describe the life cycle of filoviruses

Answer 2

Question 3

How is Ebolavirus transmitted?

Answer 3

Contact with bodily fluids (generally droplet transmission)

Question 4

T/F: Ebola can never be sexually transmitted

Answer 4

falsehood (apparently): ebola can persist and high levels of it can accumulate in sperm so it can become an STI

Question 5

Describe the transmission cycle of Ebolavirus

Answer 5

Bat>> other animals (non-human primates) >> human beings

Question 6

What are the clinical symptoms of Ebola?

Answer 6

Fever, Headache, Diarrhea, Vomiting, Stomach pain, Muscle pain

(develops into hemorrhage/bleeding from ears, nose, rectum, raised rash, severe weight loss, internal bleeding)

Question 7

What is a feature of Ebola virus that is necessary for the virus to cause recurrent infection?

Answer 7

Persistence

Question 8

T/F: There are currently no Ebola vaccines available

Answer 8

False. There are 2 vaccines available:

ChAd3-ZEBOV

rVSV-ZEBOV (V920) - currently being used

(there are also monoclonal abs: REGN-EB3, and mAb114)

Question 9

___ is an enveloped, bi-segmented ssRNA virus member of the Arenavirus family that causes Lassa Fever

Answer 9

Lassa Fever virus

**note that it had L and S segments that encode the viral proteins, and GP1 and GP2 alpha-dystroglycan receptor that are the immunodominant antigens**

Question 10

How is Lassa fever virus transmitted?

Answer 10

Its a zoonotic virus that transmitted via rodent urine + feces; person – person close contact

Spread by Mastomys natalensis

Question 11

What are the symptoms of Lassa fever in initial infection vs later stages?

Answer 11

Initial infection: inapparent infection/asymptomatic

Later on (Lassa fever): severe high fever, severe myalgia, coagulopathy, hemorrhagic skin rash, sometimes necrosis of liver and spleen

Question 12

How do you Dx Lassa fever and how do you treat it?

Answer 12

Clinical presentation

ELISA antibody testing

PCR for Lassa fever rna (detects w/in7 - 10 days)

Rx: there is no real rx. It’s palliative care and maybe Ribavarin (general antiviral so has minimal effect and high toxicity)

Question 13

Describe the structure and genomic make up of corona viruses

Answer 13

Enveloped, +ve sense ssRNA viruses; virion has spike glycoproteins which bind receptor on cells

Question 14

Which viruses make up the corona viruses? (3)

Answer 14

SARS-CoV (severe acute respiratory distress syndrome)

MERS-CoV (middle east respiratory syndrome)

“Common cold”

Question 15

Which coronavirus is ass’d with nosocomial infections?

Answer 15

MERS

Question 16

How are coronaviruses transmitted and what are their resevoirs?

Answer 16

Transmission: respiratory

Resevoirs: originally the bat, then civet cat (SARS) and camels (SARS and camels)

Question 17

How do SARS and MERS present?

Answer 17

Fever, cough, shortness of breath, progressing to pneumonia/ARDS

Question 18

What are 3 co-morbidities linked to MERS? (which one is the most common?)

Answer 18

Diabetes

Heart disease

Immunosuppression

Question 19

Which viral infection/disease process is indicated here?

Answer 19

MERS CoV

**

Edema, Diffuse alveolar damage,

thickening of alveolar septa,

multinucleated syncytial cells

Question 20

___ is a respiratory Bunyavirus that is spread thru contact with the urine and feces of the deer mouse

Answer 20

Hantavirus

Question 21

What 2 syndromes are caused by Hanta virus? Of the 2, which one is more dangerous?

Answer 21

Hantavirus pulmonary syndrome

Hemorrhagic fever with renal syndrome (worse than the pulmonary syndrome)

**note that they are caused by different strains of Hanta virus

Question 22

Describe the structure of Hantavirus

Answer 22

-ve sense ssRNA linear virus with enveloped, spherical virion

**note that the virus has S, L and M segments, which recombine to create different strains. Also, the virus has to bring with it its own RNA polymerase**

Question 23

The milder form of hemorrhagic fever w/ renal syndrome is called ___

Answer 23

Nephropathia epidemica (NE)

Question 24

HFRS is caused by which 2 subsets of Hanta virus?

Answer 24

Hantaan virus

Dobrava virus

(Hunting with Bravo)

Question 25

How does HFRS present? What 2 conditions are the hallmark of HFRS?

Answer 25

High fever, flu-like prodrome, hypotension, thrombocytopenia

Bleeding, Petechiae >> Disseminated intravascular coagulation

Renal dysfunction/failure

**hallmarks of this disease: coagulopathy and renal dysfunction

Question 26

The Sin Nombre virus (North America), Laguna negra virus, and Andes virus (South America) all cause ___

What is the presentation of this disease?

Answer 26

Hantavirus Pulmonary Syndrome

Symptoms: high fever, headache, myalgia, pulmondary edema

**hallmark of infection: respiratory symptoms LATE in the infection period**

Question 27

How do you dx Hantavirus infection?

Answer 27

Main Dx: History

Otherwise: blood test looking for atypical lymphocytes (large), thrombocytopenia, hypoxia

Hantavirus specific IgM/IgG and PCR positivity

Question 28

Which two viruses fall into the Henipavirus family?

Describe the structure of these viruses

Answer 28

Hendra virus

Nipah virus

**

Enveloped, single stranded, negative sense RNA viruses in the Paramyxovirus family (same as measles, mumps)

Question 29

How are Nipah and Hendra transmitted?

Answer 29

From bats to animals (horses) to humans

Question 30

How does Henipavirus present?

Answer 30

Incubation period is approximately 5–16 days

• Severe influenza-like illness: fever, myalgia, headache, and dizziness
• Develop severe encephalitis: confusion, abnormal reflexes, seizures, and coma
• Relapsing or late-onset encephalitis possible

Question 31

How do you Dx Henipa virus infection?

Answer 31

A. Eosinophilic viral inclusions in Nipah encephalitis

B. Acute Hendra encephalitis

C. Nipah antigen positive neurons

D. Hendra positive neuron cluster

Question 32

How do you Rx Henipavirus infection?

Answer 32

For both viruses, Rx = supportive care