DNA Viruses I Flashcards
What is the viral classification of Herpes Simplex Virus 1 and 2 (HSV1 and HSV2)?
Enveloped DS DNA virus
HSV1 and HSV2 are forms of
TORCHeS Virus
HSV1 and 2 replicate in the
Nucleus
Double stranded and linear virus
HSV1 and HSV2
Has characteristic Cowdry bodies
HSV1 and HSV2
HSV1 and 2 are transmitted via
Sex and Saliva
Affects the upper half of the body
-Called “Lip herpes”
HSV1
HSV1 1st infects as
Gingiva infantis
What is a cardinal signal of HSV1?
Snake like ulcers and keratoconjuctivitis
Can result in temporal lobe encephalitis w/ bizarre behavior
HSV1
HSV1 is the most common cause of
Sporadic encephalitis
HSV1 lies latent in the
Trigeminal ganglia
HSV1 can cause dew drop like blisters on the fingers, this is called
Herpetic Whitlow
Shows erythema multiform forming target lesions on hands and feet that move inwardly
HSV1
Transmitted by any action in the genital regions
HSV2
Characterized by painful vesicular lesion, w/ inguinal lymphadenopathy
HSV2
HSV2 lies dormant in the
Sacral ganglia
Neurologically, HSV2 can cause
Meningitis
What kind of smear do we use to look for multi-nucleated giant cells in HSV2?
Tzanc smear
There is no cure for HSV, but we can prevent breakouts with
Acyclovir and Valcyclovir
What is the viral classification of the Epstein-Barr Virus
Double stranded DNA virus
The Epstein =-Barr virus causes
Infectious mononucleosis
Shows sweating and fever
Infectious mononucleosis
Infectious mononucleosis is also classified by tender lymphadenopathy in the
Posterior cervical region
We see an increase in cytotoxic T cell in
Epstein-Barr Virus (EBV)
Epstein-Barr shows reactive lymphocytosis, aka
Downy cells
Have ab oval or folded nucleus
Downy cells
During an Epstein-Barr infection, T cells proliferate, causing
Splenomegaly
Targets B lymphocytes (white cells) in a new host
-Remains latent in B cells
EBV
Binds to CD 21, that is a receptor for compliment component CD3, to infect B Cells
EBV Envelope (glycoprotein)
Also causes pharyngitis
EBV
Occurs in late teens and adulthood, most likely asymptomatic in children
Mono
People infected with EBV will develop a maculopapular rash when treated with
Penicillin
Will not cause an allergic reaction if the patient is infected with EBV
Amoxicillin and ampicillin
EBV increases risk factors for
3 Cancers
The weakened immune system from EBV can result in the development of
B cell lymphoma or Hodgkin’s Lymphoma
EBV can also increase the risk for Non Hodgkin’s lymphoma and Burkett lymphoma, in which the most common translocation is
t8:t14
In Asian populations, EBV can increase risk for
Nasopharyngeal carcinoma
In patients with HIV and EBV, we can see a lesion that is NOT precancerous. This lesion is an
Oral hairy leukoplakia
EBV is diagnosed during actue infection by a
Monospot IgG test
What is the viral classification of the Cytomegalovirus?
DNA virus that replicates in the nucleus
Cytomegalovirus (CMV) is a member of the
Herpes virus family
CMV lies latent in
Mononuclear cells, i.e. Leukocytes
CMV can be inactivated when
Immunosuppressed
CMV is transmitted in many things, in other words it is a
TORCHeS infection
The most common fetal CMV presentation is the
Blueberry muffin rash
Most common fetal viral infection, presents with blueberry muffin rash (thrombocytopenia) petechial rash like congenital rubella
CMV
Other clinical manifestations of CMV include
Jaundice and hepatomegaly
Can result in sensoneural hearing loss
CMV infection
In the brain, CMV causes
Ventruculomegaly
Results in calcifications around ventricles and periventricle calcifications
CMV
Also can cause ventricular calcification
Toxoplasmosis
The intracranial calcifications resulting CMV can result in
Mental retardation
What percentage of the time is CMV asymptomatic?
80%
The highest risk of congenital CMV occurs during the
2nd trimester
Congenital CMV results in heart failure leading to severe edema. This is called
Hydrops Fetalis
The #1 cause of mental retardation from viral infection and the over all #1 cause of sensorineural hearing loss
CMV
Organ transplant patients can be infected with
CMV pneumonia
AIDS patients are at risk for CMV if their CD4 count is below
50
An occular characteristic of CMV is
CMV retinitis (looks like a pizza pie)
CMV esophogolitis and colitis, differ from herpes because CMV is
Singular, deep, and linear
Shows characteristic owls eye inclusion bodies
CMV infection
We can treat CMV with
Ganciclovir
When CMV has a UL97 gene mutation, treat with
Foscarnet
CMV can cause a mononucleosis that is similar to regular mono, with the exception that the monospot test would be
Negative
What is the viral classification of the Varicella Virus?
Enveloped, DS DNA Virus
Varicella virus causes the
Chicken Pox
Varicella is transmitted by
Respiratory droplets
Has the characteristic vesicular rash that is described as dew drops on a rose petal
Varicella Zoster Virus
In a case of the chicken pox, every rash is in a different stage of
Healing
The tzank smear for a varicella zoster infection shows
Multinucleated giant cells
Adults who get chicken pox can also get
Pneumonia
The vaccine for Varicella is a
Live vaccine
To treat varicella, we give
Acyclovir
Varicella virus remains latent to
Dorsal root ganglia
Varicella Zoster can become reactivated in older individuals as
Shingles
Dew drop like vesicles on an erythematous base, reactivates and travels down dorsal root in a dermatome pattern. Rarely cross the midline
Shingles
If the dermatome pattern crosses the midline then it means that we are dealing with
Disseminated VCV
The shingles rash is very
Painful
We can see pain after shingles, called
Post herpetic neuralgia
We can also see this virus infect the trigeminal nerve and cause loss of vision. This is called
Herpes Zoster Opthalmicus
We should give the Zoster vaccine for shingles vaccine to adults over
60
HIV patients can get zoster vaccine as long as their CD4 count is
Above 200
We can treat Shingles and Zoster with
Acyclovir, Famcyclovir, and Valcyclovir
Congenital varicella syndrome causes
Limb hypoplasia, Cutaneous scarring in a dermatomal pattern, and blindness
What is the viral classification of Human Herpes Virus 6?
DS DNA Virus
Human Herpes Virus 6 results in
Roseola (6th Disease)
An illness that occurs between 6 months and 2 years of age, high fever, then diffuse maculopapular lacy rash that spares the face
Roseola
Roseola is accompanied by a maculopapular rash that spares the
Face
What is the fever characteristic of Roseola?
4 day fever of over 104 degrees
In 6th disease (Roseola) The fever lasts for 4 days and then we see the appearance of the
Rash
There is no treatment for Roseola, we simply must try to keep the patient
Cool
What is the viral classification of HHV 8 (Karposi)?
DS DNA virus of the herpes family
HHV8 causes
Immunosuppression
Commonly infects AIDS patients
HHV8
Erythematous violaceous lesions on nose, extremities, and mucous membranes and may be present as a plaque, patch, macule, or nodule
HHV8
These characteristics rise from primitive mesenchymal cells involving angiogenesis causing the
Violaceus color
HHV8 causes the dysregulation of
VEGF
Also results in introintestinal lesions
HHV8
The most common lesions seen with HHV8 are in the
Hard palate
