Common Viral Diseases Flashcards
What part of viruses are the complete infective particle and do not grow?
virons
WHat are small circular RNA molecules with a rod like secondary structure that possess no capsid or envelope?
Viroids
A virus particle, also known as a virion, is made of what?
2
nucleic acid (DNA or RNA) enclosed in a protein shell or coat.
How big are viruses?
15 - 25 nanometers in diameter
The type of genetic material found in a particular virus depends on the nature and function of the specific virus.
For example, double-stranded DNA viruses typically must enter the host cell’s what before it can replicate?
Where does RNA viruses replicate?
nucleus
host cell’s cytoplasm
What is a capsomere?
Whats the funciton of a capsid?
protein units that compose the capsid of a virus
Function to protect the viral genetic material from damage.
In addition to the protein coat, some viruses have specialized structures. What is special about the flu virus?
The flu virus has a membrane-like envelope around it’s capsid.
The envelope has both host cell and viral components and assists the virus in infecting its host
The basic process of viral infection and virus replication occurs in 6 main steps. What are these steps?
- Adsorption - virus binds to the host cell.
- Penetration - virus injects its genome into host cell.
- Viral Genome Replication - viral genome replicates using the host’s cellular machinery.
- Assembly - viral components and enzymes are produced and begin to assemble.
- Maturation - viral components assemble and viruses fully develop.
- Release - newly produced viruses are expelled from the host cell.
The key components of current classification systems are?
3
- Type of symmetry of the virus capsid (helical versus icosahedral)
- Presence or absence of a lipid envelope
- Type and structure of the viral nucleic acid and the strategy used in its replication
Why does the HA and NA make the flu virus so virulent?
These protein subunits can swap back and forth and become resistant to the vaccine that has been made
Class I viruses are what kind of viruses?
What are the viruses in this class?
4
- double stranded DNA
- Papovavirus
- Adenovirus
- Herpesvirus
- Poxvirus
What are 2 examples of papovaviruses?
Examples of adenoviruses?
Examples of the herpesvirus?4
Examples of the poxvirus?
- warts, cervical cancer
- respiratory diseases
- (cold sores, genital herpes, chicken pox, mononucleosis)
- (smallpox, cowpox)
Class II viruses are what kind of viruses?
What is the virus in this class?
single stranded DNA
Parvovirus
-easy to recognize by the body because we dont have them
Class III virsuses are what kind of viruses?
What are the viruses in this class? 4
- double stranded RNA Coronavirus Picornavirus Togavirus Hepatitis C virus
WHat are examples of picornavirus? 2
What are exampes of a togavirus? 2
- (polio, common cold)
2. (rubella, yellow fever)
Class IV viruses are what kind of viruses and what viruses are in this class?5
- positive single stranded RNA itself acting as mRNA
- Rhabdovirus
- Paramyxovirus
- Orthomyxovirus
- Bunyavirus
- Arenaviruses
GIve an example of a rabdovirus?
Give an example of a paramyxovirus? 2
Give an example of an orthomyxovirus?
Give an example of a bunyavirus?
(rabies)
(measles, mumps)
(influenza viruses)
(Korean hemorrhagic fever)
WHat kind of virus is a class V virus.
What kind of virus is in this category and what does it cause?
- negative single stranded RNA used as a template for mRNA synthesis
Reovirus (diarrhea)
What kind of viruses are class VI viruses and what virus is in this class?
GIve two examples?
What kind of viruses are class VII viruses and what virus is in this category?
- positive single stranded RNA with a DNA intermediate in replication
Retrovirus (leukemia, AIDS)
- double stranded DNA with an RNA intermediate in replication.
Hepatitis B virus
Viral exanthematous diseases?
7
- Chickenpox/Herpes zoster
- Infectious mononucleosis
- Roseola infantum (Sixth Disease or Erythema subitum)
- Fifth disease (Erythema infectiosum)
- Measles
- Rubella
- Enteroviral exanthems
Enteroviral exanthems examples? 2
Coxsackievirus
Echovirus
DDx of exanthematous eruptions?
7
- Rickettsial infections
- Mycoplasma pneumoniae
- Syphilis- palms and soles
- Typhoid fever-
- Bacterial toxins- staph - toxin shock syndrome
- Drug eruptions
- Live-virus vaccinations
What are the Human herpes viruses in order?
8
- HHV-1: Herpes Simplex Virus 1 (HSV1)
- HHV-2: Herpes Simplex Virus 2 (HSV2)
- HHV-3: Varicella-Zoster Virus (VZV)
- HHV-4: Epstein-Barr Virus (EBV)
- HHV-5: Cytomegalovirus (CMV)
- HHV-6: Exanthema (or Roseola) subitum (Roseola infantum or Sixth Disease)
- HHV-7: T-lymphotropic virus (could cause cancer)
- HHV-8: Virus associated with Kaposi’s sarcoma
What viruses have the blistering rash look?
HSV 1and 2 and chicken pox