Viral infection Flashcards Preview

Theme 7 - Infection, Immunity and Inflammation > Viral infection > Flashcards

Flashcards in Viral infection Deck (16)
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1
Q

Give 6 routes of transmission of pathogens.

A
  1. Oral/Ingestion of contaminated objects
  2. Inhalation of infectious droplets
  3. Direct skin contact
  4. Trans-placental (Vertical Transmission)
  5. Sexual Transmission of bodily fluids
  6. Direct inoculation (Bites, injections, trauma)
2
Q

Describe the structure of Viruses.

A

Nucleocapsid formed from

  1. RNA or DNA Core
  2. Protein Capsid - made up of capsomeres

Some viruses also have a lipid bilayer envelope with virus-encoded glycoproteins that surrounds the nucleocapsid. This envelope is usually derived from the host cell.

3
Q

What are the different types of viral symmetries/structure shapes?

Give an example for each one.

A
  1. Icosahedral (20 faces) - Adenovirus, Herpes
  2. Helical - Flu viruses
  3. Complex - Pox, Rhabdo
4
Q

What is the effect of having an envelope as part of the structure of a virus?

A

Determines their mode of transmission

Non-enveloped viruses tend to survive well outside the body and some are bile resistant.

Enveloped viruses survive transiently outside the body so tend to be spread via close contact.

5
Q

How can different viruses be classified?

A
  • Type of Nucleic acid (DNA or RNA)
  • Number of strands of nucleic acid and their physical construction (e.g segmented)
  • Polarity of viral genome - Positive (protein can be endcoded directly) or Negative sense strand RNA
  • Symmetry of nucleocapsid
  • Whether or not they have a lipid envelope
6
Q

Hepatitis B Virus (HBV)

is a ___ virus that is found and transmitted in the ____. HBV causes _____ _______ of the Liver.

A

Hepatitis B Virus (HBV)

is a DNA virus that is found and transmitted in the Blood. HBV causes acute inflammation of the Liver.

7
Q

What virus causes chicken pox?

A

Varicella Zoster virus (VZV)

8
Q

What virus family are influenza viruses a part of?

Are these viruses enveloped and what is the polarity of their genome?

A

Orthomyxoviridae

Enveloped and Negative sense RNA

9
Q

What virus family is the HIV a part of?

Are these viruses enveloped and what is the polarity of their genome?

A

Retroviridae

Enveloped and Positive sense RNA

10
Q

What is meant by the term ‘Viral Tropism’?

A

In order for viruses to gain entry into a host cell, there needs to be a specific interaction betwwen proteins on the surface of the virus and ‘cognate’ molecules expressed on the surface of the host cell.

The need for a specific cell receptor determines what cells the virus can enter.

11
Q

To what receptor and co-receptor found on T cells do HIV-1 virions bind to, in order to gain entry?

A

Primary receptor - CD4

Co-receptor - CXCR4 Chemokine receptor

12
Q

Give examples of

A
13
Q

Describe the process of viral infection and replication.

A
14
Q

Describe the process of budding off of new virions from the host cell.

A
15
Q

What are the differences between Persistent and Latent infections?

A
16
Q

Compare and contrast the different Modes of Infection.

A