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DNA viruses


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What are the 10 DNA viruses?
1. Five Herpes viruses
2. Hepatitis B
3. Adenovirus
4. Papovaviruses
5. Parvovirus
6. Poxviruses
What are the 5 DNA Herpes viruses?
1. Herpes simplex
2. Varicella Zoster VZV
3. CMV
4. EBV
5. Human Herpes viruses 6/8
What are the 2 types of Herpes simplex HSV, what do they cause?
-Type 1: cold sores

-Type 2: genital herpes
Which of the 2 simplex herpes is more common?
Type 1
What is Whitlow?
Herpetic whitlow - sores on fingers.
How is Herpes simplex type 2 transmitted?
Via direct contact (sexual)
What are symptoms of genital herpes?
-may be Asymptomatic, or-
1. Vesicles, which pop and make painful lesions w/ crusting.
2. Recurrence - always a potential problem.
Who can get herpes?
-Men it gives dysuria
-Infants get Herpes of the eye.
How is genital herpes diagnosed?
(4 methods)
1. Culture - 100% specific and sensitive when vesicles still intact.
2. Immunological
3. Serological - most often used
4. PCR
When can culture be used to diagnose genital herpes?
ONLY when the vesicles are still intact; but they break within 24 hrs, so this is less useful.
What is VZV?
Varicella Zoster Virus
What does Varicella virus cause?
What does Zoster virus cause?
What is Varicella gangrenosa?
Bad infection when kids scratch chicken pox and get infected.
How does Shingles occur?
The virus moves up the CNS, lays latent for a while, then moves down and causes a concentrated unilateral and very painful infection.
What is the characteristic feature of CMV?
Enlarged cells with intranuclear inclusions that resemble owl's eyes.
How do humans normally get exposed to CMV, what occurs? When does it become a problem?
-Through everyday contact; get vague flu symptoms, develop immunity, never knew it.
-Problem if Pregnant woman contracts it (fetal harm), or Immunocompromised patient.
What are the 3 diseases EBV can cause?
1. Infectious mononucleosis (diagnose serologically)
2. Burkitt's lymphoma (usually in African children)
3. Nasopharyngeal carcinoma (usually in China)
What infection is HHV-6 known to cause, in whom? What are sympt?

(Human Herpesvirus)
Roseola, 6th disease, Childhood disease; Rash and high fever.
What 2 diseases may HHV-6 be associated with?
1. Bone graft rejection
2. Multiple sclerosis
How is HHV-8 transmitted, and what is it suspected to cause?
1. Transmit by blood
2. Kaposi's sarcoma - sores on mouth of Aid's patients.
Which 2 Hepatitis viruses are transmitted Fecal-oral? Are they chronic?
Hep A and E; not chronic.
What 3 Hepatitis viruses are trnsmtd via blood/body fluids?
Are they chronic?
Hep B, C, D. Yes; can become chronic.
What is unique about Hep D?
It is incomplete; can only exist with Hepatitis B.
What is Hepatitis, and what are 5 non-hepvirus causes?
Just "Inflamed Liver"
1. Viral
2. Bacterial
3. Toxic Reaction
4. Drug-induced
5. Alcohol-induced
What are 7 symptoms of Hepatitis?
1. Fever
2. Chills
3. Fatigue
4. Nausea
5. Jaundice
6. Hepatomegaly
7. Anorexia
What are 3 spcf non-hep causes of Hepatitis?
CMV, EBV, Leptospira.
How are the Hepatitis viruses diagnosed?
Serologically with Ag and Ab markers.
What is NECESSARY to diagnose the type of Hepatitis?
1. Ab markers
2. History
What are the Adenoviruses causes of? What are they possibly related to?
1. Cause respiratory tract and conjunctiva infections.
2. May relate to tendency for obesity.
What are the 2 Papovavirus types?
1. HPV (human papilloma)
2. Polyomaviruses
What 3 ways can the HPV present?
1. Common warts (flat/raised)
2. Plantar warts (on foot)
3. Genital warts
What does Genital warts do to women?
Puts them at a higher risk for cervical cancer; need frequent papsmears.
What are the 2 Polyomaviruses?
1. JC Jesus Christ
2. BK Burger King
What does the JC virus cause?
Progressive multifocal encephalopathy.
What does the BK virus cause?
It's actually subclinical, and not associated w/ any syndrome.
What 3 diseases are caused by the Parvovirus?
1. Fifth disease
2. Aplastic crisis in immunocomp
3. Fetal hydrops
What is Fifth disease?
What are 2 common symptoms?
A childhood erythematous infection.
1. Slapped Cheek Appearance
2. High Fever
What is Fetal Hydrops?
The accumulation of fluid in the body of the fetus.
What are the 4 Poxviruses?
1. Smallpox (aka Variola)
2. Vaccinia
3. Monkeypox/Tanapox
4. Molluscum contagiosum
Why do we still get educated re: Smallpox, despite eradication?
Because it has potential for bioterrorism.
What are 5 characteristics to remember re: Smallpox?
1. VERY VERY infectious
2. Causes severe poxing
3. High fever
4. only 1/3 victims survive
5. Causes severe scarring
What is the Vaccinia virus?
The vaccine for smallpox!
What is known to be a carrier of Monkeypox?
Giant Gambian rats - no they are not cute.
What symptoms are associated w/ a Monkeypox infection?
Severe lesions and fever.
What is Molluscum contagiosum?
A rare STD that causes pox lesions on the genitals.
What are Prions?
What were they previously called?
NOT Viruses; Malformed protein triggered by something. Don't respond to disinfectants, heat, or UV lite.
Prev, Slow viruses.
What is another name for Prions?
Transmissible Spongiform Encephalopathies (TSE)
What are the 4 TSEs?
1. Kuru
2. Creutzfeldt-Jakob disease
3. Bovine spongiform encephalopathy (mad cow)
4. Chronic wasting disease.
What is Kuru, how was it transmitted?
First known Prion, found in New Guinea in cannibals who ate brains at funerals.
What does Creutz-Jakob do?
Infects the CNS/brain (all TSEs do)
What is Mad Cow disease?
A new variant of Creutz-Jakob; causes CNS abnormalities in Cows; when humans eat cow, transmitted.
What is Chronic wasting disease a problem in?
What is Guillain Barre syndrome?
When does it occur?
An Ascending Paralysis that is an autoimmune disease and causes nerve demyelination via Ab.
-Follows EBV, CMV, and C. jejuni infections, possibly the flu vaccine as well!
What are the biggest organisms in medical microbiology?
What are the smallest?
What can be seen w/lite microscope? What can't?
Everything except Viruses.
what can't grow on artificial media?
-Chlamydia and rickettsiae
What is the only organism that doesn't have a cell membrane?
What doesn't have a cell wall?
-Some parasites
What is the process of culturing viruses?
1. Inoculate .2-.5 ml specimen in a cell culture tube
2. Incubate at 33 or 37'C, maybe use roller drums.
3. Observe for growth.
What cultures the fastest?
What cultures the slowest?
Fast: Herpes - 5 days at most.
Slow: CMV - up to 5 weeks.
What cultures are observed for Cytopathic effect (CPE)?
All except for:
What results are observed for identifying Influenza/Para/Mumps/Measles?
Hemadsorption - by using Guinea pig RBCs; use Rhesus RBCs for Measles.
What is Intereference used for identifying?
What is Cytopathic effect used for detecting?
HSV, CMV, Varicella Zoster, Enteroviruses, Rhinoviruses, ADenoviruses,
Resp Synctial viruses.
Compare Hep A and B:
-Type of disease
HepA: Fecal-oral trans, 2-6 wk incubation, Acute disease. -Rarely a Carrier
-aka Infectious Hepatitis.

HepB: Blood/fluid transm., 6-26 wk incubation, Acute OR Chronic disease.
-More commonly carrier state
-Aka, Serum Hepatitis
Which hepatitis virus is often tranmsmitted sexually?
Hep B
Which are the more common Hepatitis viruses seen?
Hep B - most
Hep A - 2nd
Which Hepatitises are there vaccines for?
Hep A and Hep B
Which hepatitis viruses are RNA vs. DNA?
RNA: A, C, D, E
DNA: only B
Where are the majority of HIV-infected people located?
In Subsaharan Africa - 70%
and half of those are women.
What is the leading cause of death in Africa?
What population is most at risk for getting AIDS,
-In the US
US: gay males
World: heterosexuals
How should hospital spills from an HIV-infected patient be cleaned?
with a 1:10 dilution of bleach.
What is the major immunological effect of HIV?
Destruction of CD4+ T cells; significant defect in cell mediated immunity.
What are 3 common stages in the progression of HIV?
1. Asymptomatic, but HIV Ab+
2. Prodrome to AIDS - decreased Tcells, lymphadenop, Fever for over 3 mo. Fatigue/nightsweats
weight loss, diarrhea
Kaposi's sarcoma
What changes in symptoms occur in AIDS?
-Decreased T4 cells, lymphokines, macrophage functionality.
-Frequent opportunistic infctns.
What is Kaposi's sarcoma?
A metastesizing malignancy with red to purple skin blotches.
What are the 3 most common recurrent infection in AIDs?
-Pneumocystis jiroveci (U.S.)
-Tuberculosis (worldwide)
-Oropharyngeal candidiasis
Which lab method is used to
-Screen for HIV
-Confirm the test
Screen - ELISA
Confirm - Western blot
What is normal Th to Tc ratio?
What is it in AIDS?
2:1 normally
<1 in AIDS
What is the best test for prognosis/progression to AIDS?

What is the best predictor of opportunistic infections?
-Viral load testing

-CD4 counts regularly

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