35 - Virology DNA Viruses Flashcards
what produce eruptive skin pustules called pocks or pox that leaves scars
poxviruses
what is the largest and most complex animal virus
poxvirus
what has the largest genome of all human viruses
poxvirus
describe structure of poxvirus
single linear dsDNA molecule of 130-300 kb with
hairpins at either end
where do poxvirus multiply
cytoplasm in factory areas
what does poxvirus have specificity for
cytoplasm of epidermal cells and subcutenaous CT
what are human pox viruses
- orthopoxvirus
- molluscipoxvirus
what is variola virus (smallpoxl monkeybox)
orthopoxvirus
what is molluscum contagioscum virus
molluscipoxvirus
cytopathology of pox
- extremely cytopathic
- inhibit DNA, RNA, and protein synthesis
- replication occurs in cytoplasmic factories
what is first disease eliminataed by vacc
smallpox
how does smallpox exposure occur
inhalation of skin contact
incubation period of smallpox
5-17 day
what other symptoms do smallpox pt have
high fever, headache, malaise, prostruation, rash
infections associated with smallpox
variola major and minor
variola major or minor:
highly virulent, caused toxemia, shock, and intravascular coagulation
major
variola major or minor:
less mirulent
minor
when was smallpox eradicated? when did routine vacc end
1977; 1972
when was the vaccine for small pox reintroduced for who
2002 - military and certain medical personnel
what is this:
Primarily an infection of children
in endemic areas.
Transmitted by direct contact and
fomites.
In U.S., most commonly an STD.
molluscum contagiosum
what does molluscum contagioscum look like
Lesions are 2-5 mm small,
smooth macules in genital area
and thighs.
Pearly papules with a central
depression whose core may be
expressed, producing a white
cheesy material.
symptoms of molluscume contagiosm
AIDS patients suffer an atypical
form which attacks the skin of
the face and forms tumor-like
growths.
treatment of molluscum contagioscum
freezing, electric cautery, chemical agents
how is monkeypox transmit
Transmitted by direct contact with lesions or contaminated surfaces
(bedding/towels).
Commonly intimate contact (sexual).
Also by contact with respiratory secretions.
incubation period of monkeypox
3-17 day
what is considered milder form of small pox (including pock-like rash)
monkeypox
what is this:
Lesions are firm or rubbery, well-circumscribed, deep-seated, and often
develop umbilication (resembles a dot on the top of the lesion).
Often painful until healing phase.
Typically not disseminated; commonly genital, anorectal, oral.
monkeypox
symptoms of monkeypox
Fever, lymphadenopathy (diagnostic from smallpox), malaise, headache, etc… may occur before or after lesion appearance
how is animal poxvirus transmitted
direct contact with lesions (ocupations, wild animals, cow sheep_
what do animal poxvirus look like
single nodular lesion forms at point of contact. lesion resolves after 4-5 weeks without scarring
vaccines against poxvirus
- vaccinia (ACAM2000)
- JYNNEOS
what vaccine:
Live virus used to vaccinate against Smallpox.
Distinct species of Orthopoxvirus.
Administered by variolation (skin pricking)
Vaccinia against POXVIRUS NOT SMALLPOX
clinical features of poxvirus vaccine
Localized pustular lesion at site of inoculation
Swelling of draining lymph nodes
Secondary lesions are atypical
Immunocompromised individuals
Mechanical transfer from primary inoculation site
Large number of Contraindications & Complications:
Progressive vaccinia (immunocompromised individuals)
Eczema vaccinia
Encephalitis (rare)
what vaccine:
Live-attenuated virus delivered by sub-cutaneous injection.
2 dose vaccination, 14-day interval.
Considered protective 14 days after second dose.
Unknown efficacy (immunity comparable to ACAM2000)
JYNNEOS for poxvirus
types of alpha herpesvirus
HSV-1
HSV-2
VZV
types of beta herpesvirus
CMV
HHV-6 (Roseola)
HHV-7
types of gamma herpesvirus
EBV
HHV-8 (Kaposi’s
sarcoma)
what is a common, persistent human virus
herpesvirus
what is this:
All members show latency and cause recurrent infection; viral DNA forms episome.
Clinical complications of latency and recurrent infections become more severe with advancing age, cancer chemotherapy, or other conditions that compromise the immune defenses.
herpesvirus
what is this:
Common and serious opportunists among AIDS patients.
Large enveloped icosahedral dsDNA.
Replicates within nucleus.
herpesvirus
humans are susceptible to whwat HSV
- HSV-1
- HSV-2
what HSV:
usually lesions on the oropharynx, cold sores, fever blisters Typically acquired in early childhood.
HSV-1
epidemiology of HSV
Lifelong infection.
Transmitted by secretions
and close contact.
what HSV:
lesions on the genitalia, possibly oral
Typically acquired in ages 14-29. Can be spread without visible lesions.
HSV-2
how do you get HSV-2
sexual of birth
what is ubiquitous HSV
HSV-1 is ubiquitous. World-wide estimate is 67% of the population has HSV-1. Estimated prevalence in
the Americas is 40-50%.
pathogenesis is similar for what HSV? what is the difference tho
HSV-1 and 2
1 is associated with above the waist
2 is below
how is HSV 1 and 2 transmited
Transmission by direct exposure to secretions containing the virus; active lesions most significant
source; genital herpes can be transmitted in the
absence of lesions.
where does HSV infection initiate
mucoepithelial cells
T/F: In HSV 1 and 2, local viremia and establishment of latent infection in innervating neurons.
TRUE
how does HSV 1 travel
retrograde transport to ganglia
Trigeminal (HSV-1) or Sacral (HSV-2)
what cells are inomportant for maintaining latency in HSV1 and 2
CD8 T-cells and gamma-interferon are
important for maintaining latency.
what can reactivate HSV
various stimuli