Monica - Week 5 - Exam 2 Flashcards
what are the 3 characteristics of viruses?
- smaller than bacteria
- transfers via skin or mucous membranes (sexual contact, blood, organ transplant
- replicates inside host cell (fuses to outer membrane
what is cell-mediated immunity?
- non-specific immune response
- neutrophils, macrophages respond
- lymphocytes release cytokines
what do cytokines stimulate?
stimulate immune system to attack → T/B cells
what is humoral immunity?
- specific immune response
- production of antibodies
- attack and destroy viruses
- *body remembers
what is the capsid of the virus structure?
- the capsid contains contains the virus’ genetic material (DNA and RNA)
what is the viral envelope?
the viral envelope is made from fatty lipid molecules taken from cells in the host
what is the surface proteins of virus structure?
these help the virus recognize and bind to cells in the host organism
what is the virus genetic material (DNA/RNA)?
the virus’ genetic material contains the instructions for making new copies of the virus
what are the stages of viral infection?
- virus attaches to a cell
- virus penetrates cell membrane and injects nucleic acid (DNA or RNA) into cell
- viral nucleic acid replicates using host cells (our cells)
- new viral nucleic acids are packaged into viral particles and released from the cell ***host cell may be destroyed in the process
where does herpes virus “live”?
remains latent, non-replicating state in sensory or autonomic nerve root ganglia
when does replication of herpes virus occur?
replication from immunosuppression, physical or emotional distress (fevers, surgery) → may cause reappearance of lesions
is there a cure for herpes viruses?
no cure
how is herpes virus spread?
direct physical contact with the infected person
- can be dormant
- may be asymptomatic
what is herpes simplex virus 1?
mucocutaneous herpes - eyes, mouth, lips
what is herpes simplex virus 2?
genital herpes
t/f: for HSV1 and HSV2, people can contract even when person doesn’t have symptoms present (sores)
TRUE
what is human herpes virus (HHV)-3?
varicella zoster (chicken pox) herpes zoster (shingles)
what can meds for herpes virus do?
not cure, but can ↓ severity and frequency of outbreaks
T/F: herpes zoster is common in adults > 50 y/o but can occur in 20/30 y/o as well.
TRUE
how can varicella zoster be transmitted?
DIRECT CONTACT + INDIRECT CONTACT - contact (touching blisters) - airborne (breathing) - droplet (sneezing, coughing) INDIRECT - contaminated items (linens/clothing)
when can the varicella zoster virus be spread? contagious?
can spread in 1 - 2 days before rash; people w/o visible blisters can still infect
when does transmission of varicella zoster stop?
stops when blisters dry and become crusted
T/F: varicella zoster can reactivate and cause shingles
TRUE
who gets herpes zoster?
those with a previous history of chicken pox (varicella zoster)
the active shingles virus can cause _______ in someone who has never contracted the virus
chicken pox (varicella zoster) ***can't pass shingles to shingles
how is herpes zoster transmitted?
transmitted via direct contact with blisters only
**if asymptomatic → no transmission occurs
who at risk for developing herpes zoster?
adults > 50, weakened immune system, immunosuppression therapy (corticosteroids/steroids)
how long does the blister rash of shingles usually last?
lasts 2 - 4 weeks
what are the complications of shingles?
post-herpetic neuralgia (after herpes pain; burning; can last months or years) disseminated zoster ( spreads to other areas of the skin)
when shingles becomes disseminated what other precaution needs to be put into effect?
airborne precaution - travels like dust
is there a vaccine for shingles?
yes - q 5 years, ↓ 50% may not get it
T/F: 10 - 20% of people may have shingles if you’ve had chicken pox
TRUE
how do antivirals work?
work by inhibiting viral replication; synergism (work wiith) with host’s immune system to suppress or eliminate virus
T./F antivirals work best in an immune-competent system
TRUE; not same efficiency in immunosuppressed
do antivirals guarantee full eradication of the virus?
no; may not fully eradicate a virus; helps the immune system kick in and control virus; suppresses replication
what forms does acyclovir come in?
PO, buccal, IV, and topical forms
what is acyclovir used for?
recurrent HSV-1, HSV-2, shingles, and varicella zoster