Micro 23 - RNA Viruses Part 2

Question 1

What is the actual reason for influenza’s deadliness?

Answer 1

It causes viral pneumonia but it is the secondary bacterial infections that make it deadly (superinfection). The most common bacteria are streptococcus pneumoniae and staph aureus.

Question 2

What is genetic shift?

Answer 2

Reassortment of viral genome. Can cause a complete shift in genetic material. Can lead to pandemics.

Question 3

What is genetic drift?

Answer 3

Genes becomes mutated or rearranged, leading to small changes in the influenza virus. Causes seasonal epidemics but not pandemics because the virus genome did not change much, therefore human population is better equipped to handle it.

Question 4

What does the Influenza vaccine contain?

Answer 4

The trivalent: 2 influenza A + 1 Influenza B. The Quadrivalent: 2 influ A + 2 influ B virus. They can be injectable (killed virus), Intranasal (live attenuated virus for healthy, non-preggo ages 2-49).

Question 5

What is H5N1? What are its symptoms and treatment?

Answer 5

The avian influenza, it is only spread from bird to human (no human-human spread yet). Symptoms of URI, GI symptoms (diarrhea), fever, pancytopenia, elevated aminotransferases (ALT,AST). Treated with oseltamivir.

Question 6

What is another name for Swine flu and its symptoms and treatment?

Answer 6

H1N1, derived from 2 swine flu strains, one human strain and one avian strain. Symptoms are typical flu + GI symptoms. Treatment is oseltamivir or zanamivir to high-risks or severely ill patients (but local surveillance data should guide drug choice).

Question 7

How do oseltamivir and Zanamivir work?

Answer 7

They are neuraminidase inhibitors.

Question 8

What four diseases belong to the paramixovirus family?

Answer 8

Parainfluenza/croup, Respiratory Syncytial Virus, Rubeola virus, and Mumps virus.

Question 9

What is croup?

Answer 9

It is laryngo-tracheo-bronchitis. It causes characteristic barking seal cough, respiratory distress (may mimic asthma), and inspiratory stridor.

Question 10

How is croup diagnosed?

Answer 10

Clinical, x-ray may show steeple sign (subglottic narrowing).

Question 11

What is the treatment for croup?

Answer 11

Cool mist humidifier (no proven benefit), racemic epinephrine, one dose of dexamethasone, supportive, oxygen as needed.

Question 12

What does Respiratory syncytial virus cause?

Answer 12

Bronchilitis, causes characteristic brassy cough, wheezing, respiratory distress (may mimic asthma).

Question 13

What is the treatment for RSV bronchiolitis?

Answer 13

Albuterol or racemic epinephrine, supplemental O2 as needed, steroids are not used (unless coexisting asthma). Ribavirin is not generally used in children, but may be used in adults especially if RSV develops after a bone marrow transplant.

Question 14

How do we protect against RSV for premature infants or infants with chronic lung disease?

Answer 14

Passive immunization w/ palivizumab (monoclonal RSV immunoglobulin) monthly during the winter months.

Question 15

If the test mentions winter months, what viruses do we have to keep in mind?

Answer 15

Rotavirus, RSV, Influenza.

Question 16

If the test mentions summer months, what viruses do we have to keep in mind?

Answer 16

Polio virus, Echovirus, Coxackieae virus, Enterovirus, Arbovirus.

Question 17

What does the ending -mab in a drug indicate?

Answer 17

That it is a monoclonal antibody.

Question 18

What is mechanism of action of Ribavirin? Which two disease do we use it for and what are it’s side effects?

Answer 18

It is a Guanosine analog, inhibits the synthesis of guanine nucleotides during RNA replication. Approved for the use in RSV, and hepatitis C. Can cause hemolytic anemia and is teratogenic.

Question 19

What are the symptoms of measles?

Answer 19

[The 3 Cs of Measles]
Coryza, Cough, Conjunctivitis. Koplik’s spots (pathonemonic for Measles but hard to appreciate, they are blue-gray spots on the buccal mucosa surrounded by a base of red). After those spots appear, the patient develops widespread maculopapular rash that being in head and goes down the body.

Question 20

What is it and the cause of Subacute sclerosing panencephalitis (SSPE)?

Answer 20

A chronic form of encephalitis, presents years after the person has made a complete recovery from measles. It is progressive and leads to death.

Question 21

What are the complication of measles?

Answer 21

Fetal loss, premature delivery, encephalitis (accute or chronic AKA Sunbacute sclerosing panencephalitis), giant cell pneumonia in immunocompromised patients.

Question 22

What does Mumps cause?

Answer 22

[Mumps is MOP]

Parotitis, Orchitis, Meningitis.

Question 23

What four viruses can cause viral meningitis?

Answer 23

[CEME]

Coxsackievirus, echovirus, Mumps virus, Enterovirus.

Question 24

What is the pathophysiology of Rabies virus?

Answer 24

Virus travels from peripheral nerves to CNS.

Question 25

What are Negri bodies and in what disease do we see them?

Answer 25

They are eosinophilic cytoplasmic inclusions that contain viral nuclear capsids. Seen in rabies. The rabies virus has a bullet shaped capsid.

Question 26

What are the symptoms of rabies virus?

Answer 26

Can present months or years after exposure, causes fever, malaise, nausea/vomiting, strange behavior, hallucinations, hydrophobia, coma and death.

Question 27

What are the symptoms of Hantavirus?

Answer 27

Can present as hemorrhagic fever or as pulmonary syndrome (fever, progressive pulmonary edema, ending in respiratory failure).

Question 28

How is Hantavirus spread?

Answer 28

Spread by aerosolized mouse urine. Deer mouse in USA.

Question 29

What viruses are spread by rodent urine?

Answer 29

Hantavirus, Lassa virus and LCM virus.

Question 30

What would be drugs used in prophylaxis for influenza A?

Answer 30

Zanamivir, oseltamivir.

Question 31

What drug is used in the treatment for chronic hepatitis C?

Answer 31

Ribavirin + IFN-alpha.

Question 32

What drug is first line for herpes simplex virus and varicella-zoster virus?

Answer 32

Acyclovir, valacyclovir, famciclovir.

Question 33

Which drug inhibits viral DNA polymerase when phosphorylated by viral thymidine kinase?

Answer 33

Acyclovir, valacyclovir, famciclovir.

Question 34

Which RNA virus causes characteristic barking seal cough?

Answer 34

Croup/parainfluenza.

Question 35

Which RNA virus causes childhood diarrhea in winter months?

Answer 35

Rotavirus.

Question 36

Which RNA virus causes Asthma-sounding infection in infants (esp. Preemies)?

Answer 36

RSV.

Question 37

What virus causes conjunctivitis or diarrhea?

Answer 37

Adenovirus.

Question 38

What virus causes fever, jaundice and black vomit?

Answer 38

Yellow fever.

Question 39

What virus causes enlarged cell with owl's eye inclusion?

Answer 39

CMV.

Question 40

What virus is identified with a Pap smear?

Answer 40

HPV.

Question 41

What virus causes bronchiolitis w/ cough and wheezing in babies?

Answer 41

RSV.

Question 42

What virus causes Negri bodies?

Answer 42

Rabies virus.

Question 43

What virus hides in trigeminal ganglia?

Answer 43

HSV1, HSV2, VZV.

Question 44

What virus are the two most common causes of common cold?

Answer 44

Rhinovirus, coronavirus.

Question 45

What virus causes Downey cells?

Answer 45

EBV.

Question 46

RFF: Fever, runny nose, cough, conjunctivitis, and diffuse rash.

Answer 46

Measles (rubeola).

Question 47

RFF: Small irregular blue-gray spots on the buccal mucosa, surrounded by a base of red.

Answer 47

Koplik spots in measles (rubeola).

Question 48

What family does the influenza virus belong and what are the characteristics of this family?

Answer 48

Orthomyxoviruses. They are enveloped, ssRNA that have hemagglutinin that promotes viral attachment to host cell. Also has neuraminidase which helps release progeny virons. These two things are how influenza viruses are named (the H for hemagglutinin and N for neuraminidase).