VIROLOGY

Question 1

HIV + pt comes to clinic with compliant of vision loss. He has been noncompliant with his antivirals. During a fundoscopy exam you see the following:

What is the cause of this finding?

What would you expect the pts viral load to be at?

What will you tx the disease with?

Answer 1

CMV retinopathy most common cause of HIV retinitis: you can see inflammatoyr vascular sheathing and associated hemorrhage

CD4+ counts are likely <50

Tx: Ganciclovir

Question 2

1. Exchange of genes between 2 chromosomes by crossing over within regions of significant base sequence homology.
2. When viruses with segmented genomes (e.g., influenza virus) exchange genetic material. For example, the 2009 novel H1N1 influenza A pandemic emerged via complex viral reassortment of genes from human, swine, and avian viruses.

Answer 2

1. Recombination
2. Reassortment

Question 3

When 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. For example, hepatitis D virus requires the presence of replicating hepatitis B virus to supply HBsAg, the envelope protein for HDV.

Answer 3

Complementation

Question 4

Occurs with simultaneous infection of a cell with 2 viruses. Genome of virus A can be partially or completely coated (forming pseudovirion) with the surface proteins of virus B. Type B protein coat determines the tropism (infectivity) of the hybrid virus.

****However, the _progeny from this infection have a type A coa_t that is encoded by its type A genetic material.

Answer 4

Phenotypic mixing

Question 5

Induce humoral and cell-mediated immunity but have reverted to virulence on rare occasions.

What are examples of this?

Answer 5

Live attenuated vaccines

Live attenuated: smallpox, yellow fever, rotavirus, chickenpox (VZV), Sabin polio virus, MMR, Influenza (intranasal).

“Live! One night only! See small yellow rotating chickens get vaccinated with Sabin

and MMR! It’s incredible!”

Question 6

Do we use boosters for live vaccine?

Who should not get live vaccines?

When is it okay to give HIV + people MMR live vaccine?

Answer 6

No booster needed for live attenuated vaccines.

Dangerous to give live vaccines to immunocompromised patients or their close

contacts.

Can be given to HIV- positive patients who do not show signs of immunodeficiency.

Question 7

What 4 viruses have killed vaccines?

Answer 7

Rabies, Influenza (injected), Salk Polio, and HAV vaccines.

SalK = Killed.

RIP Always.

Question 8

All DNA viruses except the _____ are dsDNA.

All DNA viruses are linear except

Answer 8

Parvoviridae (ssDNA)

papilloma-, polyoma-, and hepadnaviruses (circular).

Question 9

All RNA viruses except _____ are ssRNA.

Answer 9

Reoviridae

All are ssRNA (like our mRNA), except “repeato-virus” (reovirus) is dsRNA.

Question 10

Positive-stranded RNA viruses: I went to a retro toga party, where I drank flavored Corona and ate hippy California pickels

Answer 10

retro (retrovirus) toga (togavirus) party, where I drank flavored (flavivirus) Corona (coronavirus) and ate hippy (hepevirus) California (calicivirus) pickles (picornavirus).

Question 11

What DNA and RNA viruses are infectious?

Which are not? How do they become infectious

Answer 11

Purified nucleic acids of most dsDNA (except poxviruses and HBV) and ⊕ strand ssRNA
(≈ mRNA) viruses are infectious.

Naked nucleic acids of ⊝ strand ssRNA and dsRNA viruses are not infectious. They require polymerases contained in the complete virion.

Question 12

IG where do DNA and RNA viruses replicate?

Answer 12

DNA: in the nucleus (except poxvirus)

RNA: in the cytoplasm (except influenza)

Question 13

PNeumonic to remember enveloped viruses:

Pappi and Addy took a Pair of Pollys to Pick Real California Hippys

Answer 13

Naked (nonenveloped) viruses include Papillomavirus, Adenovirus, Parvovirus, Polyomavirus, Calicivirus, Picornavirus, Reovirus, and Hepevirus

Question 14

Generally, enveloped viruses acquire their envelopes from _____when they exit from cell.

Exceptions include herpesviruses, which acquire envelopes from ______

Answer 14

plasma membrane

nuclear membrane.

Question 15

General rules on DNA viruses

Are HHAPPPPy viruses

Are double stranded except

Are linear except

Are icosahedral expept

Replicate in nucleus expept

Answer 15

Hepadna, Herpes, Adeno, Pox, Parvo, Papilloma, Polyoma.

Except parvo (single stranded).

Except papilloma and polyoma (circular, supercoiled) and hepadna (circular, incomplete).

Except pox (complex).

Except pox (carries own DNA-dependent RNA polymerase).

Question 16

This little shit causes all sorts of prolems: oral (and some genital) lesions, spontaneous temporal lobe encephalitis, keratoconjunctivitis

What virus is this?

DNA or RNA?

ss or ds?

enveloped or not?

Answer 16

HSV-1: from Herpesvirus family

dsDNA and linear

Yes it’s enveloped

Question 17

Virus responsible for causing painless genital lesions. Can remain dormant then replicate in times of stress

Virus

DNA or RNA

ds or ss?

enveloped?

Answer 17

HSV-2

dsDNA and linear

Envelopled

Question 18

What all viruses belong to the Herpesvirus family?

What is their structure?

Answer 18

all these are dsDNA linear viruses and are enveloped

HSV-1 (oral), HSV-2 (genital), VZV or HHV-3 = chicken pox + shingles

EBV (HHV-4), CMV (HHV-5)

HHV-6 or roseola, HHV-8 = Kaposi sarcoma

Question 19

HBV is pretty nasty; its the Hep virus that gets pregnant women really sick and causes death as well as infecting babies with chronic hepatitis B and increases HCC

What is its viral structure?

enveleoped?

Do we have a vaccine?

What special enZ does it have?

Answer 19

Hepadnavirus

enveloped and is partially dsDNA and is Circular

Vaccine contains HBV surface antigens

*Not a retrovirus but has reverse transcriptase

Question 20

Pt comes in with pink eye. What virus commonly causes this?

What is it’s structure? Is it enveloped?

Answer 20

Conjucntivitis from Adenovirus

dsDNA and is linear

NOT enveloped

(adeNOvirus = NO envelope)

Question 21

You child comes home from daycare with a sore throat. You take care of them but start freaking out when you see blood in his urine. The doctor says the bug responsible is very common, especially at day care.

Bug?

and it’s structure?

Answer 21

Adenovirus: can cause pharnygitis, conjunctivitis (pink eye), viral pneumonia and

Acute hemorrhagic Cystitis

dsDNA linear virus NO envelope

Question 22

One of your sickel cell pts comes to clinic with severe pancytopenia. Her mother said some of her siblings were sick with a fever and has rashy cheeks. What’s going on?

What is responsible?

What is the structure of the virus?

Answer 22

B19 virus—aplastic crises in sickle cell disease, “slapped cheeks” rash in children (erythema infectiosum, or fifth disease)

Parvovirus B19 = -ssDNA, linear

its the tiniest DNA virus

Question 23

Mother comes in for an ultrasound of her child: you notice High amounts of amniotic fluid, an Abnormally large placenta and fluid in the liver, spleen, and other organs. You ask the mother if she’s been sick recently and she says a few weeks ago she was pretty sore in her hands, knees and ankels but thought it was just because of the baby. On the other hand, her child in day care had a high fever then had rashy cheeks. What’s the dx in the fetus?

What virus is responsible?

Answer 23

Mom has Parvovirus B19; RBC destruction in fetus leads to hydrops fetalis and death, in adults leads to pure RBC aplasia and rheumatoid arthritis–like symptoms

-ssDNA virus NO envelope

Question 24

What strains of HPV cause genital warts?

cervical cancer?

What famliy of virus do they belong to and what is their structure

Answer 24

HPV–warts (serotypes 1, 2, 6, 11), CIN, cervical cancer (most commonly 16, 18)

Papillomavirus

dsDNA, circular adn NO envelope

Question 25

HIV pt comes to clinic very disoriented. You are looking over his list of medications and notice a rheumatology doctor prescribed him Rituximab. You are very concerened that his current status will progress rapidly and be fatal. You get imaging of his brain and see below. What diseaes does this pt have? Why? What pathogen was responsible?

Answer 25

progressive multifocal leukoencephalopathy Demyleninating disease from destruction of olidendrogliomas (myelinate CNS) Caused by Reactivation of **JC virus in HIV** pts often from Rituximab dsDNA cirucular , no

Question 26

What two viruses are in the Polyomavirus family? What is their structure? What disease do they cause?

Answer 26

dsDNA, circular and NON enveloped **JC virus**—progressive multifocal leukoencephalopathy (PML) in HIV **BK virus**—transplant patients, commonly targets **kidney** J C: Junky Cerebrum; BK: Bad Kidney

Question 27

This virus was erradicated by a live attenuated vaccine. In cows it causes milkmaid blisters. Before it was erradicated it caused Acute disseminated (postinfectious) encephalomyelitis or ADEM Virus? Structure?

Answer 27

Small pox: Pox virus dsDNA linear and LARGEST DNA virus ENVELOPED

Question 28

Mother is concerned about her daughter, she has several bumps around her belly. You look and they are flesh-colored papule with central umbilication. You assure her its nothing to worry about but encourage her daughter not to pick at them and they should go away in a few months Dx Structure of virus

Answer 28

Molluscum contagiosum **dsDNA linear virus, enveloped** (do need to be aware may be STD)

Question 29

Teenager comes to clinic with a sore throat, fever and fatigue. Her exam is significant for posterior cervical lymphadenopathy. You suspect it's viral and have seen several of her classmates with the same illness. You inform her mother she needs to be out of contact sports for 6 weeks and to get plenty of rest and stay hydrated. What test would you order to confirm her illness? What would you see on peripheral smear? What cancers is this implicated in?

Answer 29

Detect by ⊕ Monospot test—**heterophile antibodies** detected by agglutination of sheep or horse RBCs Atypical lymphocytes seen on peripheral blood smear are not infected B cells but rather **reactive cytotoxic T cells.** Associated with lymphomas (e.g., endemic Burkitt lymphoma), nasopharyngeal carcinoma.

Question 30

How do you get EBV? What cells are infected? What type of virus is this? What is it's structure?

Answer 30

Transmitted by respiratory secretions and saliva; also called “kissing disease” since commonly seen in teens, young adults. **Infects B cells through CD21.** **H**erpesvirus: dsDNA, linear and enveloped

Question 31

Patinet comes to the office with posterior cervical lymphadenopathy, fever and feels very lethargic. You perform a test and notice that it does not cause any clumping of horse serum. What would you expect to see on peripheral smear? What is the dx? What do you tx it with?

Answer 31

infected cells have characteristic “owl eye” inclusions CMV (herpesvirus) Use Ganciclovir!

Question 32

What is the MOA of the drug used to tx heterophile - monouncleosis?

Answer 32

heterophile - is CMV use Ganciclovir: 5′-monophosphate formed by a CMV viral kinase. Guanosine analog. Triphosphate formed by cellular kinases. _Preferentially inhibits viral DNA polymerase._ Preferentially inhibit viral DNA p_olymerase by chain termination._

Question 33

Your HIV pts comes to clinic with vision issues. You note he has a CD4+ under 100. What is the cause of his vision problems? What is the drug you will tx him with if Ganciclovir fails: ? What is it's MOA? Toxicity?

Answer 33

CD4 under 100 think CMV retinits in AIDS pt Tx with **Foscarnet**: **Viral DNA/RNA polymerase inhibitor** and HIV reverse transcriptase inhibitor. Binds to _pyrophosphate-binding site of enzyme. D_oes not require activation by viral kinase. Nephrotoxicity

Question 34

Mother comes to the hospital in a panic with her little girl. She's had a high fever for several days not and then starting shaking on the floor. You calm the mother down and explain that she's fine and febrile seziures are common with the virus she has. What should you tell teh mother to be on the look out for over the next few days? What is the virus? It's struture?

Answer 34

Roseola: high fevers for several days that can cause seizures, followed by a diffuse macular rash Transmitted by saliva. HHV6/7 dsDNA linear and enveloped

Question 35

Young woman comes in worried about several small vesciles on her genitals. You take a scraping and prep them on a slide (see below) Whats the Dx?

Answer 35

Tzanck test— multinucleated giant cells commonly seen in HSV-1, HSV-2, and VZV infection A . **Intranuclear inclusions (below)**also seen with HSV-1, HSV-2, VZV.