VIRAL Flashcards
non-enveloped RNA
my Real Heavy Picture of California was Ruined without an envelope
reovirus
hepevirus
picornavirus
calicivirus
RNA
non-enveloped DNA
PaPa and Aunt Poly Didn’t have an envelope
parvovirus
papillomavirus
adenovirus
polyomavirus
DNA
in general, where do DNA viruses replicate?
nucleus
in general, where do RNA viruses replicate?
cytoplasm
DNA viruses that replicate in the cytoplasm
smallpox
molluscum contagiosum
RNA viruses that replicate in the nucleus
influenza virua
retroviruses
recombination
exchange of genes between 2 chromosomes of similar viruses, in regions of significant base sequence homology
reassortment
viruses with segmented genomes exchange genetic material. This can lead to pandemics
complementation
1 of 2 viruses that infect the cell has a mutation that results in a nonfunctional protein. The nonmutated virus complements the mutated one by making a functional protein that serves both viruses. (Hep B and D)
phenotype mixing
simultaneous infection of a cell with 2 viruses. genome of A can be partially or completely coated with surface proteins of virus B. This changes its tropism. Future progeny, however have surface components encoded by their unchanged type A genetic material.
virus ploidy
number of copies of RNA or DNA present in virion.
All RNA and DNA viruses are haploid, except retroviruses (which are double stranded)
DNA viruses
HAPPy HiPPo Dung
herpesvirus adenovirus parvovirus papillomavirus hepadnavirus polyomavirus poxvirus DNA
DNA viruses
usually have linear dsDNA
replicate in the nucleus
icosahedral shape
exceptions: small parvovirus (ssDNA) papillomavirus (circular) polyomavirus (circular) hepadnavirus (circular)
RNA viruses
positive- sense ssRNA
serves as mRNA for immediate translation to protein
can also be transcribed to -ssRNA, which serves as a template for more +ssRNA
neg-sense RNA must be transcribed to pos-sense before they can be used as template for translation
positive- sense RNA viruses
retrovirus togavirus flavivirus coronavirus hepevirus calicivirus picornavirus
live attenuated vaccines, which induce immunity via subacute infection
smallpox yellow fever chickenpox MMR sabine polio (oral) herpes zoster (shingles) intranasal influenza rotavirus
killed virus vaccines
formed from whole, killed viruses
may require booster to maintain protective immune response over an extended period of time
injectable influenza
rabies
hep A
salk polio (injectable)
subunit vaccines
use specific viral antigens to simulate immune response
hep B
HPV
yellow fever/influenza/MMR and egg allergy
YF: skin testing and desensitization
Influenza: if no history of anaphylaxis
MMR: egg all is not a contraindication
HIV patients and vaccines
all infants with HIV should receive rotavirus vaccine
CD4>200
MMR
Varicella
Not recommended
live virus influenza
Herpes zoster
heterophile negative mononucleusis
CMV infection acute HIV acute toxoplasmosis viral hepatitis strep throat
EBV- associated malignancies
Hodgkin lymphoma Burkitt lymphoma Nasopharyngeal carcinoma Diffuse large cell lymphoma Oral hairy leukoplakia Lymphoproliferative disorders
CMV and bone marrow transplant patients
life-threatening PNA
CMV and HIV
retinitis (blindness within days)
GI ulcerations
candida esophagitis
acyclovir, valacyclovir, famciclovir
herpes treatment
guanosine analog
first phosphorylated by thymidine kinase
inhibits DNA polymerase after it is incorporated into the viral DNA chain
valacyclovir is the valyl ester of acyclovir and is quickly hydrolized to acyclovir
activity against HSV1 and HSV2
VZV, EBV
Famciclovir is a prodrug of penciclovir and relies on viral thymidine kinase (acyclic guanosine nucleoside analog)
HSV1, HSV2, VZV
Famciclovir and valacyclovir are preferred over acyclovir for herpes zoster
Ganciclovir
activated by CMV viral kinase
inhibits viral DNA polymerase
Adverse effects:leukopenia, neutropenia, renal toxicity
look for falling blood cell counts and rising creatining
more toxic to host enzymes than acyclovir
use for CMV, especially in immunocompromised patients
Foscarnet
Inhibits DNA polymerase
Does not require activation by viral kinase
adverse effects:
renal toxicity, anemia
uses:
resistant HSV
CMV retinitis not responsive to first-line treatment
HSV1, HSV2, VZV treatments
acyclovir
valacyclovir
famciclovir
CMV treatment
ganciclovir
foscarnet
what group of patients is prone to esophagitis cause by CMV?
AIDS patients with CD4
Where do HSV1, HSV2, VZV, CMV, and EBV remain latent?
HSV1- trigeminal ganglia HSV2- sacral ganglia VZV- doral root or trigeminal ganglia CMV- mononuclear cells EBV- B cells
What are Downey cells?
T-cells that respond to EBV infection
Parvovirus
ssDNA
parvovirus B19 infects humans
classically presents with transient aplastic crisis in sickle cell patients
Also causes erythema infectiosum (fifth disease) in children “slapped cheek rash”
(in the area of CN5)
adults- inflammatory arthritis
in utero: hydrops fetalis and miscarriage
(other in the ToRCH list)
HPV
ds, circular
types 1 and 2
common warts
types 6 and 11 genital warts (90%)
types 16 and 18
invasive cervical cancer
vulvar, anal, penile, head and neck cancers
Adenovirus
dsDNA URI followed by conjunctivitis febrile pharyngitis acute hemorrhagiv cystitis PNA
Poxvirus
ds linear
Smallpox
Cowpox
Molluscum contagiosum
Smallpox (variola)
ds linear poxvirus
cause by enveloped variola poxvirus virus
eradicated 1979
bioterrorism possibility
Cowpox (vaccinia)
ds linear poxvirus
caused by vaccinia virus
“milkmaid blisters”
provides immunity to smallpox
Molluscum contagiosum
ds linear poxvirus
flesh- colored dome- shaped lesions with central dimple (umbilication)
resolves in less than a year on its own
polyomavirus
ds, circular
JC virus- progressive multifocal leukoencephalopathy (PML) in HIV
JC: junky cerebrum
BK virus: targets kidney
Hepadnavirus
hepatitis B virus
partially DNA, circular
hepatitis virus
kind of like a retrovirus
- partially double-stranded circular DNA enters nucleus
- in the nucleus, host polymerase makes RNA intermediate from DNA
- viral reverse transcriptase makes DNA from RNA intermediate
Burkitt lymphoma and nasopharyngeal carcinoma
EBV
gingivostomatitis
HSV1
erythema infectiosum (fifth disease)
parvovirus B19
heterophile-positive mononucleosis
EBV
causes conjunctivitis or diarrhea
adenovirus
enlarged cell with “owl’s eye” inclusions
CMV
identified with Pap smear
HPV
milkmaid’s blisters
cowpox (vaccinia virus)
Burkitt lymphoma and nasopharyngeal carcinoma
EBV
gingivostomatitis
HSV1
hides in sensory ganglia of S2 and S3
HSV2
hides in trigeminal ganglia
HSV1
hides in dorsal root ganglia
VZV
viral family of JC virus
Polyoma virus
Downey cells
EBV
human progressive multifocal leukenceophalopathy
JC virus
oral hairy leukoplakia
EBV
multinucleated giant cells on Tzanck smear
HSV1, HSV2, VZV
only DNA virus that is not double stranded
parvovirus
roseola
HHV6
heterophile- negative mononucleosis
CMV
What cell type is infected in EBV?
B cells
prophylaxis for influenza A
zanamivir, oseltamivir
used in treatment for chronic hepatitis C
Ribavirin, IFNalpha
first- line for herpes simplex virus or varicella- zoster virus
acyclovir, valacyclovir, famciclovir
inhibits viral DNA polymerase when phosphorylated by viral thymidine kinase
-cyclovirs
can cause conjunctivitis or diarrhea
adenovirus
fever, jaundice, black vomit
yellow fever
enlarged cell with “owl’s eye” inclusions
CMV
identified with a Pap smear
HPV
“barking seal” cough
parainfluenza (croup)
bronchiolitis with cough and wheezing in babies
RSV (paramyxovirus)
Negri bodies
rabies
hides in trigeminal ganglia
HSV1, HSV2, VZV
diarrhea in children during winter months
rotavirus
2 most common causes of common cold
coronavirus
rhinovirus
Downey cells
EBV
aseptic meningitis
enterovirus, mumps
