Viruses Flashcards
Name respiratory viruses (5)
flu, RSV, parainfluenza, rhinovirus, coronavirus
name rash viruses? 4
measles, rubella, chickenpox, parvovirus
what viruses are spread by mucosal? 2
- Herpes simplex virus
- HIV
which virus is spread cutaneously?
*Human papillomavirus
what viruses are spread by ingestion? 3
- Norovirus
- Rotavirus
- Hepatitis A and E
which virsuses are spread via blood? 3
- HIV
- Hepatitis B
- Hepatitis C
which viruses are spread from mother to child in utero? 4
- Cytomegalovirus
- Rubella
- Parvovirus B19
- Varicella
which viruses are spread perinatal? 3
- HIV
- Hepatitis B
- Herpes simplex virus
which viruses are spread by ingestion? 2
- Hepatitis E
- Hantaviruses, Lassa
which viruses are spread by insects?
- Dengue,
- Zika,
- West Nile (mosquitoes)
- Crimean Congo - Haemorrhagic Fever
- tick-borne encephalitis (ticks)
which virus is spread via animal bite?
rabies
what are the steps of viral replication? 6
- Viruses use glycoproteins to attach to the cell wall receptor
- Virus inside, RNA virus will replicate in the cytoplasm, DNA virus will replicate in the nucleus
- Multiplies its copy of genome
- RNA will be transcribed and translated into proteins
- Virus made and capsid assembled
- Escape out of the cell by enveloping or bursting the cell
how to prevent viral spread? 3
Physical – condoms, DEET
Passive – antibody
Active – vaccines
* Killed
* Engineered antigen
* Live attenuated
what are the antivriral classes? 4
- Non- specific – interferon
- Replication – nucleoside analogues
- Release – oseltamivir
- Others – protease inhibitors
Name two antiviral drugs that are Neuraminidase inhibitors?
Oseltamivir (Tamiflu) and Zanamivir
name 3 antivirals that are nucleotide analogues?
Acyclovir (Zovirax), valaciclovir, famciclovir
what antivirals are used for cytomegalovirus?
Ganciclovir, valganciclovir, cidofovir, foscarnet, letermovir
what antivirals are RNA polymerase inhibitors?
- RSV, Lassa fever (rarely used)
What is a defining characteristic of viruses?
They require a host cell to replicate
Which structure is NOT found in all viruses?
Lipid envelope
Which viral shape consists of 20 flat triangular sides forming a nearly spherical structure?
Icosahedral
What distinguishes a retrovirus from other RNA viruses?
It uses reverse transcriptase to convert RNA into DNA
What is an example of a retrovirus?
HIV
Enveloped viruses are generally:
More sensitive to detergents
Which virus has a negative sense RNA genome?
Influenza
What role does integrase play in the retroviral replication cycle?
Helps viral DNA integrate into the host genome
How do positive-sense ssRNA viruses replicate?
Their RNA genome acts as mRNA and is directly translated
Which of the following is NOT a feature of enveloped viruses?
They are resistant to environmental stress
What is a characteristic of obligate intracellular parasites like viruses?
They require a host cell to reproduce
Why do RNA viruses mutate more frequently than DNA viruses?
RNA viruses lack proofreading mechanisms
What is the primary reason why some viruses integrate their genome into the host DNA?
To facilitate long-term persistence in the host
How do airborne viruses primarily spread?
Via aerosols that remain suspended in the air
Why is it difficult to develop antiviral drugs?
Viruses use host cells to replicate, making it hard to target them without harming the host
What is a physical method of viral infection prevention?
Condom use
What is the mechanism of action of nucleoside analogues like Acyclovir?
They inhibit viral DNA polymerase by mimicking nucleotides
Which class of antiviral drugs prevents the integration of viral DNA into the host genome?
Integrase inhibitors
Which immune response is the first line of defense against viral infections?
Innate immunity
Which type of immune cell specializes in killing virus-infected cells that have reduced MHC-I molecules?
Natural Killer (NK) cells
How do viruses evade the immune system?
A) By changing their antigens
B) By interfering with immune signaling
C) By entering a latent phase
What is viral latency?
The ability of a virus to remain dormant within a host cell
Which of the following viruses is known to establish latency in the trigeminal ganglia?
Herpes simplex virus (HSV-1)
Which virus is known to establish latency in memory T cells?
HIV
What is an example of passive immunity against viral infections?
Antibody therapy
What is the main reason some viruses develop drug resistance?
Frequent mutations in their genome
What is the role of protease inhibitors in antiviral therapy?
They prevent the cutting of viral proteins into functional units
Which of the following viral diseases is primarily treated with uncoating inhibitors?
Influenza
What is a major challenge in designing antiviral drugs?
Viruses replicate inside host cells, making selective targeting difficult
What is the main benefit of vaccines in viral infections?
They stimulate the immune system to recognize and fight future infections
