RNA viruses

Question 1

Little boy, daycare, horrible diarrhea. Viral infection. What is the structure of the virus he is infected with?

Answer 1

Rotavirus: (Reovirus)

dsRNA linear

NO envelope

iscosahedral

Question 2

What is the strcture of the Picornaviruses?

What the Picornaviruses?

are they ds or ss?

Answer 2

+ssRNA: linear and Icosahedral, NO env

PERCH

Poliovirus—polio-Salk/Sabin vaccines—IPV/OPV

Echovirus—aseptic meningitis in the summer

Rhinovirus—“common cold”

Coxsackievirus—aseptic meningitis;

Herpangina (mouth blisters, fever); hand, foot, and mouth disease; myocarditis; pericarditis HAV—acute viral hepatitis

Question 3

Common cause of aseptic meningits in the summer?

What is this viral structure?

Answer 3

Echovirus: +ssRNA; linear and icosahedral; no envelope

Question 4

This nasty virus causes aseptic meinigit, herpangina (mouth blisters, fever); hand foot adn mouth disease and myocarditis; pericardits

Strcture of virus?

Answer 4

Coxsackievirus

(type of Picornovirus = ssRNA linear with icosahedral and no envelope)

Question 5

GI upset on a cruise ship

Bug?

genetics?

Answer 5

Norovirus (Calicivirus)

+ssRNA; linear with NO envelope

Question 6

What do the following viruses all have in common?

HCV
Yellow fevera
Denguea
St. Louis encephalitisa

West Nile virus

Answer 6

All Flavivirus:

+ssRNA, Linear and Icosahedral,

ENVELOPED

Question 7

Friend was in Thailand and comes back very ill. She is experienceing severe bone pain. What is the virus responsible?

ss or ds?

env or not?

Answer 7

Dengue fever

Flavivirus

ssRNA Linear Icosahedral

ENVELOPED

Question 8

Little boy with fever, swollen lymph nodes then developes rash starsts on face and then on body

As rash disappeares, skin flakes off.

Dx?

Structure of virus?

Answer 8

Rubella or German Measels

Togavirus:

+ssRNA Linear virus

Icosahedral

ENVELOPED

Question 9

Virus that causes common cold and is responsible for SARS?

Structure?

Answer 9

Coronavirus

+ssRNA linear and Helical

Enveloped

Question 10

What is the structure of the Influenza virus?

What family is it in?

Enveloped?

Answer 10

-ssRNA linear with 8 segments

Helical and ENVELOPED

from orthomyxofamily

Question 11

What all diseases belong in the Paramyxoviruses?

What is their strcture?

Answer 11

PaRaMyxovirus:

• *P**arainfluenza—croup
• *R**SV—bronchiolitis in babies;(ribavirin )

Measles, Mumps

-ssRNA linear with Envelope

Question 12

Baby with seal bark cough. What virus do they have? what’s it’s structure?

Answer 12

Croup = paramyxovirus

-ssRNA linear with capsid

ENVELOPED

Question 13

MMR vaccine covers what viruses?

What are their strctures?

Answer 13

Measels and Mumps = Paramyoviruses ; -ssRNA linear with helical caspid and ENVELOPED

Rubella = German measels= Toga virus and +ssRNA linear Icosehedral with ENVELOPE

Question 14

What is the most common cause of viral pneumonaie in children around two ages?

What can you tx it with?

Answer 14

RSV; paramyxovirus = +ssRNA linear with helical capsid and Envelope

tx RSV with Ribavirin

Question 15

Virus that causes fear of water and death!

family?

strcture?

Answer 15

Rabies = Rhabdoviruse

-ssRNA linear with ENVELOPE adn helical capsid

Question 16

California encephalitisa
Sandfly/Rift Valley feversa
Crimean-Congo hemorrhagic fever

Hantavirus—hemorrhagic fever, pneumonia

Answer 16

Bunyavirus: -ssRNA

enveleoped with 3 segments

Question 17

-ssRNA circurlar virus, Enveloped and is known as a ‘defective’ virus

Answer 17

Hepatitis D

Question 18

Pneumonic for (-) virus

What do they need to bring with them to infect cells?

Always Bring Polymerase Or Fail Replication.

Answer 18

must transcribe ⊝ strand to ⊕.

Virion brings its own RNA-dependent RNA polymerase.

They include Arenaviruses, Bunyaviruses, Paramyxoviruses, Orthomyxoviruses, Filoviruses, and Rhabdoviruses.

Question 19

What viruses are segmented viruses?

BOAR

Answer 19

All are RNA viruses. They include

Bunyaviruses,

Orthomyxoviruses (influenza viruses),

Arenaviruses

Reoviruses

Question 20

Picornavirus: Poliovirus, Echovirus, Rhinovirus, Coxsackievirus, and HAV.

RNA is translated into 1 large polypeptide that is

Answer 20

cleaved by proteases into functional viral proteins.

Question 21

What diseases are caused by the Picornaviruses?

Answer 21

PERCH: Picornavirus, Echovirus, Rhinovirus, Coxsackievirus, HAV

Can cause aseptic (viral) meningitis (except rhinovirus and HAV).

All are enteroviruses (fecal-oral spread) except rhinovirus.

Question 22

Rhinovirus causes shit tons of colds. What is route of transmission? What type of virus is it? Why does it cause enteral illness like all the other Picornoviruses?

Answer 22

Rhinovirus = picornovirus

+ssRNA linear; non-enveloped

Acid labile! = destroyed by stomach acid

Question 23

Pt with expansive travel hx comes to office with high fever and is jaundice. She is freaking out because she puked up stuff that look like ground coffee!

dx?

What is the vector?

Answer 23

Yellow fever: Flavivirus = +ssRNA linear and is Enveloped

transmitted by Aedes mosquitos

Question 24

Rotavirus A , the most important global cause of infantile gastroenteritis, is a segmented _____ virus (a reovirus). Major cause of acute diarrhea in the United States during winter, especially in day care centers, kindergartens. Villous destruction with atrophy leads to ?

Answer 24

dsRNA

absorption of Na+ and loss of K+.

*CDC recommends routine vaccination of all infants.

Question 25

What are two structures unique to influeza virus?

What is their function?

What severe complications do we worry about with influenza virus infection?

Answer 25

Orthomyxoviruses. Enveloped, ⊝ ssRNA viruses with 8-segment genome.

Hemagglutinin (promotes viral entry)

Neuraminidase (promotes progeny virion release)

Contain antigens. Patients at risk for fatal bacterial superinfection, most commonly
S. aureus, S. pneumoniae, and H. influenzae.

Question 26

What structure promotes H.flu e_ntry into the cell_?

What promotes virion release?

Answer 26

hemagglutinin (promotes viral entry)

neuraminidase (promotes progeny virion release) antigens

Question 27

Reformulated vaccine (“the flu shot”) contains viral strains most likely to appear during the flu season.

Which vaccine is most commonly used?

Which one is administered intra-nasaly?

Answer 27

Killed viral vaccine is most frequently used.

Live attenuated vaccine contains temperature- sensitive mutant that replicates in the nose but not in the lung; administered intranasally.

Question 28

Compare and contrast genetic drift and shift

Answer 28

Shift = pandemics. Reassortment of viral genome segments, such as when segments of human flu A virus reassort with swine flu A virus.

Drift=epidemics. _Mino_r (antigenic drift) changes based on random mutation in hemagglutinin or neuraminidase genes.

Question 29

A little boy coes in with mother. He spiked a high fever and had a rash on his face but now it has spread to the rest of the body. You note lymphademopathy as well.

Dx?

What if the mother contracts this while she is pregnant?

Answer 29

German (3-day) measles: Togavirus–rubella

Congenital rubella findings include “blueberry muffin” appearance, indicative of extramedullary hematopoiesis

Question 30

MOther delivers her baby and you are concerned she may have gotten ill with something while pregnant. Below is a picture of the infant.

What was the cause of the rash?

What would this look like in a young child?

Answer 30

Congenital Rubella = Togavirus (+ssRNA linear and enveloped)

Blueberry muffin rash = extramedullary hematopoeisis

causes German measels or Rubella = fever with rash starting on face and spreading to body

Question 31

Paramyxoviruses :They include those that cause parainfluenza (croup: seal-like barking cough), mumps, and measles as well as RSV, which causes respiratory tract infection (bronchiolitis, pneumonia) in infants. All __________, which causes respiratory epithelial cells to fuse and form multinucleated cells.

What drug can we give to premies with RSV to prevent this?

Answer 31

contain surface F (fusion) protein

Palivizumab (monoclonal antibody a_gainst F protein)_ prevents pneumonia caused by RSV infection in premature infants.

Question 32

3 yo comes in and you dx him with viral pneumonia?

Wha the most likely agent?

What is the way in which this bug cauases disease?

Answer 32

viral pneumonia in young children = RSV

(paramyxovirus -ssRNA and Enveloped)

All contain surface F (fusion) protein, which causes respiratory epithelial cells to fuse and form multinucleated cells.

Question 33

All Paramyxoviruses (parainfluenza, measels, mumps, RSV) contain surface F (fusion) protein, what is it’s mechanism in the respiratory system that causes damage?

Answer 33

respiratory epithelial cells to fuse and form multinucleated cells

Question 34

During peds rotation you notice young child with a maculopapular rash on her arms and stomach. You check on her the next day and it is now on the tops of her legs. She has a cough and conjunctivitis.

What would you expect to find on oral examination?

What is responsible?

What can you give to prevent excoriation of rash in malnourished child?

Answer 34

Measels Virus: Paramyxovirus

See Koplick spots: bright red with blue-white centers prescede the rash

Vitamin A to prevent sever exfoiliatve dermatitis

Question 35

What are teh three C’s of measels?

What virus is this?

What can occur later d/t measels

Answer 35

Cough, Coryza, Conjunctivitis

Measels = Paramyxovirus: -ssRNA; linear and ENVELOPED

SSPE (subacute sclerosing panencephalitis, occurring years later), encephalitis (1:2000), and giant cell pneumonia (rarely, in immunosuppressed) are possible sequelae.

Question 36

Mom brings her son in to docotr. He’s been very sick lately and she says his lymph nodes seem pretty swollen. You are looking through his history and see there have been NO vacccines. You notice swollen testicals and swollen parotid glands.

What are immediate concerns with this virus?

Late concerns?

Answer 36

Immediate: can cause Aseptic meningits

Future: sterility in men

From Mumps: paramyxovirus: -ssRNA linear and enveloped

Question 37

A 25 yo male is brougt in to urgent care by his girlfriend. He has generalized maliase and a fever. In hx you discover he likes to catch game in the wood with his brothers and has some bite marks on his arm. You culture the bite and notice a Bullet-shaped virus. He says he got bit by a racoon a few days ago while hunging.

How do you tx this pt?

What characteristics are seen if this progresses withouth tx?

Answer 37

RABIES!

Postexposure prophylaxis is wound cleaning plus immunization with killed vaccine and rabies immunoglobulin. Example of passive-active immunity.

Progression of disease: fever, malaise ?agitation, photophobia, hydrophobia, hypersalivation?paralysis, coma?death.

Question 38

Pt comes into clinic delirious, aggitated and states light ‘KILLS’ his eyes. You offer water to the pt to get a urine sample but he refuses. Shortly after he lapses into a coma and dies.

What is the mechanims by which this virus causes diseas?

What do you expect to see on autopsy?

Answer 38

Rabies virus = bullet shaped (Rhabdovirus = -ssRNA linear enveloped)

Travels to the CNS by migrating in retrograde fashion up nerve axons after binding to ACh receptors

Negri bodies B commonly found in Purkinje cells of cerebellum and in hippocampal neurons.

Question 39

Pt presents with abrupt onset of flu-like symptoms, diarrhea/vomiting, high fever, myalgia. You notice schistocytes in blood work and shortly after they go into shock and die. Eveyone is put into isolation. What is the virus that caused this and what parts of body does it affect?

How is it transmited?

Answer 39

Ebola: filovirus that targets endothelial cells, phagocytes, hepatocytes.

Transmission requires direct contact with bodily fluids or fomites (including dead bodies); high incidence of nosocomial infection.

Question 40

Often an asymptomatic virus and is acquired thorugh the fecal oral route

Not associated with HCC risk

What is the virus

Answer 40

Hep A virus

ssRNA pircornavirus

Question 41

What is the genome of Hep B?

HOw is it transmitted?

What is it’s risk for HCC?

Answer 41

Hep B = dsDNA virus it’s a hepadnavirus

transmission is parenteral or sexual adn maternal-fetal

Increased HCC risk and integrates into the host genome; acts as an oncogene

Question 42

What type of virus is Hep C?

What is it’s transmission?

What increased risks are seen with it?

Question 43

How does the Hep B virus replicate in the host?

Answer 43

In HBV, the DNA polymerase has both DNA- and RNA-dependent activities. Upon entry into the nucleus, the polymerase functions to complete the partial dsDNA.

The host RNA polymerase t_ranscribes mRNA from viral DNA_ to make viral proteins.

The DNA polymerase then reverse transcribes viral RNA to DNA, which is the genome of the progeny virus.

Question 44

HAV and HEV are fecal-oral: The vowels hit your bowels.

What is special about these two?

Answer 44

Naked viruses do not rely on an envelope, so they are not destroyed by the gut.

Question 45

RNA delta virus from sexual transmission. Seen along with Hep B

Answer 45

Superinfection (HDV after HBV)—short

Coinfection (HDV with HBV)—long

Defective virus Dependent on HBV; superinfection ??prognosis

Question 46

What is present during a Hep B infection during the window period?

During Recovery?

If you are immunized

Answer 46

Window: Absent HBsAg Anti-HBs but PRESENT is HBeAg and the IgM or Anti-HBc

Recovery: Present is Anti-HBs, Anti-HBe and Anti-HBc (IgM)

Immunized: Anti-HBs