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Flashcards in Micro 23 - RNA Viruses Part 2 Deck (48)
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What is the actual reason for influenza's deadliness?

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.


What is genetic shift?

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


What is genetic drift?

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.


What does the Influenza vaccine contain?

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).


What is H5N1? What are its symptoms and treatment?

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.


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

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).


How do oseltamivir and Zanamivir work?

They are neuraminidase inhibitors.


What four diseases belong to the paramixovirus family?

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


What is croup?

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


How is croup diagnosed?

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


What is the treatment for croup?

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


What does Respiratory syncytial virus cause?

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


What is the treatment for RSV bronchiolitis?

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.


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

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


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

Rotavirus, RSV, Influenza.


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

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


What does the ending -mab in a drug indicate?

That it is a monoclonal antibody.


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

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.


What are the symptoms of measles?

[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.


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

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


What are the complication of measles?

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


What does Mumps cause?

[Mumps is MOP]
Parotitis, Orchitis, Meningitis.


What four viruses can cause viral meningitis?

Coxsackievirus, echovirus, Mumps virus, Enterovirus.


What is the pathophysiology of Rabies virus?

Virus travels from peripheral nerves to CNS.


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

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


What are the symptoms of rabies virus?

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


What are the symptoms of Hantavirus?

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


How is Hantavirus spread?

Spread by aerosolized mouse urine. Deer mouse in USA.


What viruses are spread by rodent urine?

Hantavirus, Lassa virus and LCM virus.


What would be drugs used in prophylaxis for influenza A?

Zanamivir, oseltamivir.