Viruses & Disease Flashcards
What is unique to each virus & can be used to identify them
The protein coat (capsid)
Do viruses contain ribosomes
No
Virus Life Cycle
- Virus binds to receptor on host cell
- Host replicates viral components
- New viruses assemble
- Viruses released from host cell
6 modes of viral transmission
- Oral transmission
- Direct skin contact
- Sexual transmission
- Droplet transmission
- Direct inoculation
- Trans placental
How has smallpox been eradicated
Variolation
Vaccination
Is smallpox a DNA or RNA virus
DNA virus
Where does the herpes virus lie dormant
In the trigeminal nerve
Recurrence of herpes infection is causeed by what
- Immunosuppression
- Stress
- Insufficient sleep
Different manifestations of herpes
- Cold sores
- Shingles
- Chickenpox
Is herpes a DNA or RNA virus
DNA virus
What happens in the life cycle of retroviruses that is different?
Reverse transcription of RNA to DNA occurs
What is the target cell of HIV
CD4 lymphocyte (T cell)
Steps in HIV retrovirus infection
- Virus binds to CD4 cell of host
- Viral RNA transcribed to DNA via reverse transcriptase (RT) enzyme
- Incorporates into host genome
- It replicates
- Released from host CD4 cell
Function of CD4 T cell
Immune memory
4 modes of transmission HIV
- Unprotected sex
- Blood transfusion
- Needles (contaminated/sharing)
- Mother to baby
HIV therapies
- Education
- Clean needles
- Contraceptives
- Antivirals
Antivirals used to treat HIV
- Combination anti retroviral therapy (ART)
- Nucleosides, Protease inhibitors, RT inhibitors
- HIV triple therapy
- Resistance - vaccines?
Is HIV a DNA/ RNA virus
RNA virus
4 zoonotic viruses
- Influenza
- HIV
- Ebola
- SARS-CoV-2
Is SARS-CoV-2 a DNA/RNA virus
RNA virus
How is SARS-CoV-2 spread
- Via droplets
- Persistence via mucus: virus remains in the airways
What receptors does SARS-CoV-2 bind to
ACE2 receptors on host cells
SARS-CoV-2 binds to ACE2 receptors where?
In the respiratory tract
Which antibodies do vaccines induce
IgG antibodies
Steps of zoonotic transmission of SARS-CoV-2
- Virus is maintained in bats (reservoir hosts), undergoes 25-60 years of mutations
- Virus jumps to susceptible species (intermediate hosts)
- Virus jumps to humans through contact with infected animals (spillover to humans)
- Virus spreads from person to person (human to human transmission)
