Term
| Who can Orthomyxoviridae infect? |
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Definition
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Term
| What do members of Orthomyxoviridae cause? |
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Definition
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Term
| How many strain types of influenza are there and what are they? |
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Definition
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Term
| Which strains of influenza cause human disease? |
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Definition
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Term
| Currently, outside of SARS, _______ is most likely to do us damage. |
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Definition
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Term
| What classification are Orthomyxoviridae? |
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Definition
Baltimore Class V
(-) ssRNA |
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Term
| What is unique about the Orthomyxoviridae RNA? |
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Definition
| it is segmented; 8 segments each code for certain genes |
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Term
| Are Orthomyxoviridae enveloped or non-enveloped? |
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Definition
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Term
| What are the two types of spike proteins that are found on the envelope of Orthomyxoviridae? (also important RNA segments & major antigens!) |
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Definition
1. Hemagglutinin (HA)
2. Neuraminidase (NA) |
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Term
| Can the A & B strains of influenza virus also target animals? |
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Definition
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Term
| In what species is the C strain of influenza found? |
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Definition
| animals only, so far (not jumped to humans yet) |
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Term
| What is HA used for by the influenza virus? |
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Definition
| binding to our host cells (uses sialic acid as receptor); hemagglutination of RBC |
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Term
| What is NA used for by the influenza virus? |
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Definition
| allows the viruses to be released from the host cells |
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Term
| What does "A" stand for in HA & NA? |
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Definition
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Term
| What is the receptor for the influenza virus? |
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Definition
| sialic acid on epithelial cells |
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Term
| How does influenza virus get into the cell? |
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Definition
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Term
| What happens to the influenza virus after endocytosis? |
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Definition
| the capsid escapes from the vesicle and enters the nucleus |
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Term
| Where is the viral influenza mRNA transcribed from (-) RNA? |
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Definition
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Term
| How is the viral influenza mRNA transcribed from (-) RNA? |
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Definition
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Term
| Where is viral influenza mRNA translated into protein? |
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Definition
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Term
| How does the influenza virus escape from the cell? |
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Definition
| it buds from the CYTOPLASMIC MEMBRANE! |
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Term
| How is influenza transmitted? |
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Definition
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Term
| Where does influenza infection initially occur? |
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Definition
| in the upper respiratory tract |
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Term
| What are the primary cell targets for the influenza virus? |
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Definition
| ciliated, mucus-producing cells |
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Term
| What are the basic "flu-like" symptoms caused by infection with influenza virus? |
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Definition
1. fever
2. myalgia
3. headache
4. malaise
5. nonproductive cough
6. sore throat
7. chills |
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Term
| What are many of the basic "flu-like" symptoms caused by infection with influenza virus associated with? |
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Definition
| interferon & cytokine induction |
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Term
| What are some of the more severe lower respiratory infection problems caused by infection with influenza? |
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Definition
1. shedding of the bronchial epithelium
2. compromised immune response
3. promotes secondary bacterial infection (ex - pneumonia) |
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Term
| What is the hallmark of influenza viruses? |
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Definition
| antigenic change & genetic diversity |
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Term
| How do new strains of influenza develop? |
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Definition
| mutation & segmentation reassortment |
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Term
| How do we monitor public health in regard to influenza virus? |
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Definition
| surveillance of influenza strains |
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Term
| What is the "nature" of the influenza virus? |
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Definition
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Term
| What is the range of possibilities for infection related to influenza virus? |
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Definition
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Term
| What organs does influenza usually involve? |
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Definition
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Term
| Who is considered "high risk" for influenza virus infection? |
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Definition
1. children
2. elderly
3. immunosuppressed
4. people with heart & lung conditions |
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Term
| What is the incubation period of influenza virus? |
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Definition
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Term
| What complications can arise with infection by influenza virus? |
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Definition
1. secondary bacterial infections (often pneumonia)
2. Reye's syndrome
3. Guillain-Barre syndrome
4. CNS involvement |
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Term
| T-cell responses are important with influenza virus infection for... |
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Definition
| effecting recovery & immunopathogenesis |
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Term
| antibodies are important concerning the influenza virus to... |
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Definition
| prevent the disease (including vaccine-induced Ab) |
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Term
| Concerning the influenza virus, the cell-mediated immune response... |
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Definition
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Term
| Concerning the influenza virus, the antibody-mediated response is.. |
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Definition
| specific for each strain of influenza. |
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Term
| Concerning the influenza virus, T-cell memory may provide... |
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Definition
| future protection against infection by different strains of A or B |
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Term
| How do we generally diagnose influenza virus? |
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Definition
1. symptoms
2. epidemic state |
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Term
| What is useful for the early treatment of influenza virus? |
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Definition
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Term
| What vaccine is available for influenza virus? |
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Definition
| inactivated; trivalent against A & B types |
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Term
| What must happen to HA of the influenza virus in order for it to be infectious and attach? |
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Definition
| HA must be cleaved by a host cell serine protease |
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Term
| What are the influenza virus vaccines based on? |
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Definition
| the HA (hemagglutinin antigen) |
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Term
| Antigenic drift of the influenza virus results from... |
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Definition
| minor changes in the HA & NA due to mutation |
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Term
| Antigenic shift of the influenza virus results from... |
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Definition
| major changes in HA due to genetic reassortment btw viruses co-infecting animal hosts |
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Term
| Antigenic drift of the influenza virus occurs... |
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Definition
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Term
| Antigenic drift of the influenza virus causes... |
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Definition
| local outbreaks of A & B infection |
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Term
| antigenic shift of the influenza virus occurs ONLY with... |
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Definition
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Term
| The major changes of influenza virus antigenic shift are often associated with... |
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Definition
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Term
| antigenic shift of the influenza virus does NOT occur with strain B primarily because... |
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Definition
| it is predominantly a human virus |
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Term
| How often does antigenic shift of the influenza virus occur? |
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Definition
| infrequently, but it can be devastating |
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Term
| Who all should get the seasonal flu vaccine? |
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Definition
| all people 6 months of age and older |
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Term
| What are some issues with the flu vaccine? |
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Definition
1. thimerosal (mercury)
2. autism (recent data says probably not)
3. Guillain-Barre syndrome (neurological, body reacts w/ immune response that crosses w/ nerves) |
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Term
| What are the approved vaccines for influenza virus? |
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Definition
1. IM single dose (INACTIVATED!)
-2 type As, 1 type B
-probably given to most people
2. Intranasal single dose (LIVE ATTENUATED)
-often used with children |
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Term
| How does Amantadine work? |
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Definition
| inhibits M2 (matrix protein), an ion channel in envelope that helps virus uncoat & get in cell |
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Term
| What is a problem with Amantadine? |
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Definition
| current viruses are resistant to it; recommended not to use in recent flu seasons |
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Term
| What is another treatment for the flu? |
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Definition
| Tamiflu - oseltamivir & zanamivir |
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Term
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Definition
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Term
| When is the best time to take Tamiflu? |
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Definition
| ASAP! (preferably before fever) |
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Term
| What strain is the Avian Flu we looked at in class? |
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Definition
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Term
| The flu is contagious; how is it easily passed? |
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Definition
1. coughing
2. sneezing
3. nasal secretons
4. "togetherness" - especially in peak season (think winter) |
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Term
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Definition
antigenic SHIFT
-5 RNA segments from swine flu
-2 RNA segments from bird flu
-1 RNA segment from human flu |
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Term
| How can we protect ourselves from the flu? |
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Definition
1. vaccines
2. handwashing
3. masks |
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Term
| What is the general U.S. flu season? |
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Definition
| Nov/Dec, peak Jan/Feb, never really @ 0 |
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Term
| Why is the influenza virus so unique? |
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Definition
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Term
| What about the influenza virus makes it able to change so rapidly? |
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Definition
1. the RNA being replicated by RNA polymerase; poor job that makes lots of mistakes and leads to lots of variants (only HIV can compete)
2. can infect a variety of animals successfully
3. multiple segments allow interchanging (hybrids!) if cell infected with more than one influenza virus strain (A) |
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Term
| What four things contribute to the genetic diversity of the influenza virus? |
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Definition
1. we are a reservoir
2. also produces disease in pigs & birds
3. swap back & forth within a community
4. enough variation allows virus to move into humans |
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Term
| What is special about influenza vRNP? |
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Definition
| it has an enzyme that clips off 5' cap from our message & puts it on the viral message |
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Term
| What is the consequence of the action of influenza vRNP? |
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Definition
1. viral message gets processed like a normal RNA
2. our cells can't make protein b/c caps being stolen
3. cap & tail degradation results
4. w/o cap & tail we can't produce enough message
5. viral message is now protected
7. LYTIC CELL |
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Term
| List four influenza pandemics, when they occurred, and what type of flu it was. |
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Definition
1. Spanish Flu (1918-1919), H1N1
2. Asian Flu (1957-1958), H2N2
3. Hong Kong Flu (1968-1969), H3N2
4. Swine Flu (2009-2010), H1N1 |
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Term
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Definition
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