Unit 3 Viral Pathogenesis Flashcards
For viruses, infection simply means entry of a virus into a host cell
This type of infection has new infectious particles produced inside the host cell
For this type, few, if any new viral particles are produced inside the host cell. Not good for the virus.
Productive Infections
Abortive Infections
Abortive infection is sometimes due to 2 things:
Mutation (of the virus)
Protective mechanisms of the host
This type of infection is of short duration, signs/symptoms observed, and then infection is cleared (immunity results)
Prime example is the
Acute infections
(rapid in rapid done)
Rhinovirus
This type of infection is not completely eliminated after primary infection
What is the example of this
Latent Infections
Herpesviruses (there are 8)
This herpes virus is primarily responsible for cold sores but it could also be
Genital ulcers are usually this herpes virus but can also be
HHV-1 is primarily responsible, can also be HHV2 (genital ulcers is a symptom too)
HHV-2 is primarily responsible, HHV-1 can cause them as well
Chickenpox and shingles are this herpes virus
HHV-3 (varicella zoster)
This term means virus is in the blood, and applies to chickenpox before rashes emerges. Explains why rashes appear all over body
Viremia
This is the reactivated form of chickenpox and is more localized, can be activated by stress. A vaccine is out there to keep our immune system in check for it.
Shingles
This herpes virus causes mononucleosis (sick and tired all the time) and Burkitt lymphoma, a reactivated version of it, especially common in HIV positive individuals
It likes to reproduce inside of ____ cells
HHV-4
B cells
This herpes virus is associated with Kaposi Sarcomi, also associated with HIV positive status. Causes an overgrowth of blood vessels underneath the skin.
HHV-8
Latency is maintained inside ___ cells, by maintaining a circular ___ during latency
These help maintain latency
Nerve cells
Circular Episome
Latency associated transcripts (LATs)
Stress, UV light, hormonal changes, and getting over other sicknesses may cause reactivationcc
!
This is the term for chronic infections, where new viral particles are continuously produced. The host doesn’t clear the virus even though signs and symptoms may cease
Persistent Infections
Persistent infections may be a result of a targeted weakening of the immune system or mutational changes in the virus and/or changes in the virus and/or changes in host target cells
!
Examples of persistent infection include
Do these illnesses always become persistent in individuals?
HIV, hepatitis B and C
No, but they can in some individuals and do.
Viruses must be able to leave one host and enter another. What are the 4 basic types of transmission
Horizontal Transmission
Vertical Transmission
Zoonotic Transmission
Vector Transmission
This type of transmission is due to an animal passing it onto a human
This is more specific, is flea or blood sucking animal
Zoonotic Transmission
Vector Transmission
Which type of viral transmission passes between friends, or from individual from individual within the same species. Includes respitory, fecal oral, and sexual transmission
Which can be passed through mother to offspring in unborn children
Horizontal Transmission
Vertical Transmission
Rhinovirus, influenza, poliovirus, hepatitis A, HIV and HPV are what type of transmission?
Horizontal Transmission
This type of transmission occurs within the same species but from mother to fetus or newborn. Can be transmitted through the ____ or during birth via blood.
The virus can also be transmitted by bodily secretions like
A few viruses can even be transmitted via these type of cells, spermatocytes/oocytes infected with mouse mammary tumor virus
Vertical Transmission, placenta (rubella aka German measles, Hep B and C, HIV)
Breastmilk (HIV)
Germ line cells (reproductive cells)
Facilitated transfer of virus from host to host via another vector, like yellow fever or the myxoma virus
How is it different from zoonotic?
Vector Transmission
Animal isn’t affected by pathogen, it’s more specific (blood sucking insect passes it from one organism to another)
What are the two ways a virus can kill a body cell
What is the other way body cells can die?
Necrosis and Apoptosis
The immune system (kills infected body cells)
This type of viral induced cell death causes the cell to burst
Is this usually naked or enveloped virion?
What are three mechanisms that cause the cell to burst?
Necrosis
Naked (only way to get out, no spike protein)
Overfilling cell with new viruses
Viral impairment of normal cell function
Additionally, the virus produces particles that weaken the membrane (some)
What symptom is necrosis associated with?
What is inflammation caused by?
Inflammation
Tissue damage that releases chemicals that trigger immune response (chemicals inside cells, like via process of necrosis)
This is the more subtle death of cells that is safer for surrounding cells. The cell commits suicide, sometimes as ordered by the immune system to safely kill virally infected cells.
Apoptosis
During apoptosis, internal events occur that degrade DNA into small fragments, bits of cell are released as ______
Does this induce inflammation?
Blebs
No, not rupturing/leaking the cell contents out