Week 139 - Influenza Flashcards Preview

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Flashcards in Week 139 - Influenza Deck (72):
1

Describe Norovirus

  • +SS RNA virus
  • Member of Caliciviridae family
  • Causes gastroenteritis in closed communities such as crusie ships or hospitals etc

 

1

Describe Parvovirus B19

  • SS DNA virus
  • Member of Parvoviridae family
  • Causes Erythema infectiosum (slapped cheek syndrome)

2

Describe Rabies virus

  • -SS RNA virus
  • Member of Rhabdoviridae family
  • Causes rabies

 

2

Describe Human Herpesvirus 6 & 7

  • DS DNA virus
  • Member of Herpesviridae family
  • Causes Roseola infantum

2

What mucous membranes allow the entry of viruses and give an example virus that enters in that way

  • Genital - HSV, CMV, HIv
  • Respiratory - Measles, Influenza, Chickenpox
  • GI - Hepatitis A, Polio, Rotaviruses
  • Eye - HSV, Adenoviruses

3

Which viruses caused upper respiratory infections?

  • Rhinovirus
  • Coronavirus
  • Parainfluenza virus
  • Respiratory syncytical virus
  • Influenza virus
  • Adenovirus
  • HSV
  • EBV

4

Describe Astrovirus

  • +SS RNA virus
  • Member of Astroviridae family
  • Causes gastroenteritis in adults and children

4

Decribe Rubella virus

  • +SS RNA virus
  • Member of Togavirdae family
  • Causes Rubella

 

4

Which classes of viruses use the host's DNA-dependent RNA polymerase?

  • DS DNA viruses
  • SS (+/-) DNA viruses

5

Describe Adenovirus

  • DS DNA virus
  • Memeber of Adenoviridae family
  • Causes upper respiratory tract infections and gastroenteritis

7

Describe Respiratory syncytial virus

  • -SS RNA virus
  • Member of Paramyxoviridae family
  • Causes respiratory infections - leading cause of bronchiolitis in children

9

What is the basic structure of a virus?

9

Which cells does measles infect after entry through the respiratory epithelium?

Dendritic cells

10

Describe Influenza virus

  • -SS RNA virus
  • Member of Orthomyxoviridae family
  • Causes respiratory infections such as flu

11

What free radicals are produced during an infection?

  • Superoxide free radical (O2.)
  • Nitric oxide (.NO)

13

Describe Coxsachie virus 

  • +SS RNA virus
  • Member of Picornaviridae family
  • Causes hand, foot and mouth in children and also gastroenteritis

14

How do retroviruses replicate within the host cell?

  • They are incorporated into the host's genome
  • They are then replicated using the host's own replication machinery

15

Which virus can cause lower respiratory tract infections?

  • Parainfluenza virus
  • Respiratory syncytial virus
  • Influenza
  • Adenovirus

16

What are the 3 main route of viral penetration

  1. Translocation of the entire virus across the plasma membrane
  2. Fusion of the viral envelop with the external cell membrane (from without or pH-independent)
  3. Receptor-mediated endocytosisn (pH-dependent)

16

How does aciclovir exert its anti-viral effects?

It is incorporated into the viral DNA because of its similarity to guanosine but does not allow DNA chain extension

16

What viruses is aciclovir effective against?

HSV and VZV only 

16

When is Oseltamivir (Tamiflu) prescribed?

  • When circulating levels of influenza are high
  • Prophylaxis or treatment of high risk patient

16

What are the side effects of Oseltamivir?

  • Headache
  • Nausea
  • Cough

 

16

What are the 3 problems every virus must overcome to survive?

  1. How to replicate inside the host cell
  2. How to spread from one host to another
  3. How to evade host defences

16

What viruses are linked to immunosuppresion?

  • HIV - infect helper T cells
  • Measles - infects dendritic cells and macrophages
  • Epstein-Barr virus- infects B cells

18

Describe Papillomavirus

  • DS DNA virus
  • Member of papillomaviridae family
  • Causes warts

19

Describe mumps virus

 


  • -SS RNA virus 



  • Member of Paramyxoviridae family 




  • Causes mumps 

 

20

Describe measles virus


  • -SS RNA virus 



  • Member of Paramyxoviridae family 




  • Causes measles 

 

21

What viral infections is ganciclovir used for?

Cytomegalovirus infections such as retinitis or pneumonias etc

23

What are the 7 stages of the viral lifecycle?

  1. Attachment
  2. Penetration
  3. Uncoating
  4. Replication
  5. Assembly
  6. Maturation
  7. Release

26

Describe Molluscum contagiosum virus

  • DS DNA virus
  • Member of Poxviridae family
  • Causes Molluscum contagiosum

28

Describe the parainfluenza virus


  • -SS RNA virus 



  • Member of Paramyxoviridae family 




  • Causes respiratory infections - leading cause of croup 

28

How do enveloped viruses get released from the host cell?

They bud off, using the host's own plasma membrane as an envelope

29

How is aciclovir activated?

  1. Viral thyamine kinase first to aciclovir monophospahte
  2. Host cell kinase to aciclovir triphosphate, which the active compound

30

What is the course of a rabies infection?

  1. Following inoculation, the virus may replicate locally, but then it enters the PNS, where is passively travels to the CNS
  2. The virus next infects the brainstem, cerebellum, and other brain structures (diffuse encephalitis)
  3. From the brain, the rabies virus can travel along the autonomic nerves, leading to infection of other tissues including the cornea, skin and salivary glands

32

Describe Epstein-Barr Virus

  • DS DNA virus
  • Member of Herpesviridae family
  • Causes glandular fever

33

What is used to produce NO?

L-arginine

34

Which class of virus is able to be translated directly inside the host cell?

(+) mRNA viruses

35

Where does the measles virus replicate?

Inside the lymph nodes

35

What is the post-exposure procedure for rabies?

  1. Wash wound immediately with soap and water
  2. Instillation of Ig serum around wound
  3. Ig injections given in a series of doses over a month

35

Which cell of the immune system is the main cause of virus induced pathology?

T cells

37

Describe cytomegalovirus

  • DS DNA virus
  • Member of Herpesviridae family
  • Causes CMV infection

 

38

Which classes of virus use viral RNA-dependent RNA polymerase to replicate?

  • SS (-) RNA viruses
  • DS RNA viruses

38

What insults to the skin allow the entry of viruses and give an example virus that enters in that way

  • Minor trauma - Warts, Herpetic whitlow
  • Insects - Yellow fever, Dengue fever
  • Needles - Hepatitis B & C, HIV
  • Bites - Rabies

39

What are the side effects of aciclovir?

  • GI side effects
  • Neurotoxicity

40

Describe Human T-cell lymphotropic virus

  • +SS RNA virus
  • Member of Retroviridae family
  • It is an oncogenic virus with a very long latency period (20-30 years)

42

Describe Herpes Simplex Virus 1 & 2

  • DS DNA viruses
  • Members of Herpesviridae family
  • Causes mouth (HSV-1) and genital (HSV-2) ulcers

43

What structure of the influenza virus does Amantadine target and what does this cause?

It targets the ion channel in the envelope which prevents acidification of the virus and subsequent viral release.

45

Describe rotavirus

  • DS RNA virus
  • Member of Reovirdae family
  • Causes gastroenteritis in children

 

47

What viral process does Aciclovir stop?

Replication

48

Describe Varicella Zoster Virus

  • DS DNA virus
  • Member of Herpesviridae family
  • Causes chickenpox, reaction of latent infection causes shingles

49

What are the different types of persistent viral infections?

  • Chronic 
  • Latent
  • Subclinical (Carrier state)
  • Insidious

50

Describe Poliovirus

  • +SS RNA virus
  • Member of Picornaviridae family
  • Causes polio

 

51

What enzyme is used to produce NO during an infection?

inducible nitric oxide synthase (iNOS)

52

Which viruses cause a localised gastrointestinal infection?

  • Coronavirus
  • Rotavirus

54

Where in the cell does the influenza virus replicate?

Nucleus

55

What are the side effects of ganciclovir?

  • Neutropaenia  or anaemia (1 in 10)
  • Thrombocytopaenia, leucopaenia or pancytopaenia (1 in 100)
  • Diarrhoea
  • Dyspnoea
  • Liver/kidney damage
  • Tremor

56

How are naked viruses released from the host cell?

Lysis of the host cell when the concentration of virus reaches threshold

58

What is viral uncoating?

The removal of the protein coat or viral capsid and exposure of the viral genome within the cell

59

What is the structure of the influenza?

60

What other anti-viral, apart from Oseltamivir are available for influenza?

Zanamivir (Relenza)

62

Describe Coronavirus

  • +SS RNA virus
  • Member of Coronavirdae family
  • Causes respiratory and gastrointestinal infections such as common cold, gastroenteritis in adults and SARS

63

When does the viral particle become infectious?

After maturation, which may occur pre- or post-release from the host cell

64

What are the direct  cytopathic effects caused by viral infection?

  • Cell death
  • Blockage of host protein synthesis
  • Blockage of macromolecules entering or exiting the cell
  • Breakdown of the cell cytoskeleton

 

65

When does measles cause the greatest damage to the respiratory epithelium?

When it replicates in the epithelium before it leaves the host

66

What viruses are thought to enter the host through M cells in the GIT?

  • Reovirus
  • Coronavirus

67

68

What are the indirect effects of viral infections?

  • Injury caused by the immune system and free radicals
  • Immunsuppresion
  • Disruption to normal body functions

69

How is ganciclovir administered?

12 hourly IV infusion for 14-21 days. followed by maintainance doses whilst immune system compromised

70

Which route of viral penetration is the most common?

Receptor mediated endocytosis

71

What gastrointesinal viruses can cause a systemic infection?

  • Entrovirus
  • Adenovirus

72

Describe Rhinovirus

  • +SS RNA virus
  • Member of Picornavirdae family
  • Causes respiratory infections - leading cause of common cold