RNA Viruses Flashcards
(59 cards)
1
Q
What are the positive stranded RNA viruses?
A
1) Caliciviruses
2) Flaviviruses
3) Togaviruses
4) Coronaviruses
5) Retroviruses
6) Picornaviruses
2
Q
What are some negative stranded viruses?
A
1) Rhabdoviruses
2) Filoviruses
3) Bunyviruses
4) Arenaviruses
5) Reoviruses
6) Paramoyxoviruses
7) Orthomyxoviruses
3
Q
What are the Caliciviruses?
How is it spread?
A
- Norwalk virus (leading cause of viral gastroenteritisi), Hep. E
- Spread via fecal-oral transmission
4
Q
What are the clinical symptoms present in Norwalk virus?
A
- Diarrhea and Nausea, fever in 1/3 of patients, incubation 24-48 hours.
5
Q
What are the major diseases spread with Flavivirdae?
A
- Yellow fever, west nile, St. Louis encephalitis, Japanese encephalitits, Japanese encephalitis, Dengue, yellow fever, hep C
6
Q
How are Flaviviridae transmitted?
A
- are transmitted through arthropods- mosquitos
7
Q
What is the pathogenesis of Flaviviridae?
A
primary- general: chills, headaches, and backaches
secondary- viremia- might affect the brain, liver, skin, and vasculatures
8
Q
How is St. Louis Encephalitis virus transmitted?
Age group?
A
- culex mosquito
- attacks in adults older than 40
9
Q
What are the symptoms of West Nile Virus?
What is the time frame of the initial West Nile virus?
What is the time frame of the more severe form?
A
- Mild form - fever, headache, body aches, occasional rash on trunk - several days
- Severe form - (encephalitis)- high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, and paralysis - several weeks
10
Q
Where is Dengue fever found?
How is Dengue fever transmitted?
A
- middle East, Africa, Far East, Caribbean
- transmitted by the Aedes mosquito
11
Q
What is Dengue fever’s other name, from its symptoms?
What are the symptoms associated?
A
- “Break bone fever” - severe muscle and bone aches
- muscle and joint paint, N&V, rash and hemorrhagic manifestations (cytokine storm) - 6-7 days
12
Q
Where is yellow fever classically contracted?
What are the systemic symptoms in the more severe form?
A
- Caribbean, Central, South America, Africa
- Severe systemic disease with degeneration of liver, kidney, heart, and hemorrhage.
- -> liver involvement = jaundice (yellow fever)
- -> GI hemorrhages = black vomit
13
Q
How is Hepatitis C spread?
What is the percentage of patients with Hep C that get chronic cirhosis?
A
- parenteral and sexual contact
- 80%
14
Q
What type of vaccine is available for yellow fever and who is it given to?
A
- Live attenuated vaccine given to travelers
15
Q
How are most of the togaviruses spread?
What is not transmitted similarly?
A
- arboviruses- mosquitos
- Rubella is not spread by mosquitoes
16
Q
What are the disorders associated with togaviruses?
A
- eastern equine encephalitis
- western equine encephalitis
- venezuelan equine encephalitis
- Chickungunya
- Rubella
17
Q
What are the hosts of western, eastern, and venezuelan encephalitis?
A
- horses
18
Q
How is Rubella transmitted?
Why is it harmful to babies?
A
respiratory droplets
- crosses the placents
19
Q
What can differentiate Rubella from Rubeola (measles)?
What can differentiate congenital Rubella from CMV?
A
- Rubella (german measles) - patient has very pronouced lymphadenopathy - not seen in measles
- Congenital Rubella can present with infant cataracts (only one that can).
20
Q
What vaccine is available for Rubella?
A
- MMR- R is for Rubella
21
Q
What is the diseases most associated with coronaviridae?
A
- Common cold (second most common cause) and SARS
22
Q
What is the transmission of coronaviridae?
Where do you need to travel to get this?
A
- Respiratory droplets
- China, Toronto,
23
Q
What are the disorders associated?
A
- Enteroviruses: polio virus, coxsackie A, coxsackie B, Echoviruses
- Rhinovirus
24
Q
What is the normal pathogenesis of picornaviridae?
A
- Viral replication initiated in the mucosa and lymphoid tissues
- Primary viremia spreads virus to receptor bearing targets
- Secondary viremia - polio must cross BBB and gain access to brain by skeletal muscle traveling up.
25
How are picornaviridae transmitted? What type of disease is it not?
- Fecal- Oral transmission
| - Not an enteric disease - weird!
26
What are the symptoms in the polio virus?- what is the percentage in this form.
- flaccid muscle paralysis (anterior horn cell degeneration) but preservation of sensory
- .1-2%- 80% are asymtomatic
27
What is the major disease manifestation of Coxsackie A?
| Where is it frequently found?
Hand-Foot and mouth disease- vesicular lesions on hand, feet, and mouth.
- Daycare
28
What is the main clinical vingenette of a coxsackie B patient?
- sudden onset of heart failure in a young adult (20s)
| - fecal oral spread
29
What virus is commonly transmitted with consumption of undercooked shellfish from sewage infested water?
What vaccine would be used to treat it?
- Hepatitis A virus
| - inactivated vaccine
30
Where and why does the rhinoviruses stay once in the body?
| What receptor does 80% of Rhinoviruses bind to?
- In the upper respiratory tract becuase they can only replicate at 33 degrees celcius
- ICAM receptors
31
What is the main disease associated with Rhabdoviruses?
| - What are the shaped of the viruses?What other diagnostic clues are important?
- Rabies
- bullet shaped,
- Negri bodies (cytoplasmic inclusions in brain)
32
What transmits rabies?
| Once infected how and where does the virus travel?
- bats, raccoons bites , in countries without vaccinations then dogs are main carrier.
- Retrograde axoplasmic to the dorsal root ganglia
33
How long can the virus incubate before signs develop?
| What are the classic symptoms associated with rabies?
- months -
- Prodrome stage: headache, fever, GI, fatigue, anorexia,
- Neurological Stage: Hydrophobia, seizures, disorientation, hallucination, paralysis, confusion, delirium
- Coma:
34
What are the big disease manifestation of Ebola?
| What is its major symptom?
- Ebola
- Severe or fatal hemorrhagic fever due to entering vascular endothelial cells leading to them bleeding in the liver, spleen, LN, and lungs --> edema and shock.
35
Where is this virus mainly found?
| Is this an aerosol virus?
Africa
| - no, need direct contact with blood/ secretions
36
Bunyavirus transmission?
| Pathogenesis?
- Arboviruses, except for hantavirus - RODENT born
- Directly to the blood - primary viremia to CNS, liver, kidney, and vascular endothelium causing neuronal or glial cell damage, cerebral edema leading to encephalitis.
37
Transmission of bunyavirus?
- mosquitoes, ticks, etc. Humans are infected. (Feces can become aerosolized) when they enter the environment of the vector.
38
What is the prominent symptomatic feature of hantavirus?
- hemorrhagic tissue destruction and lethal pulmonary complications, myalgia in the legs, once cardiopulmonary phase begins put on ventilator then it rapidly progress
39
Area significant for Hantavirus?
- SE US - Arizona
40
What is a key feature of the progression of arenaviridae?
- takes cellular ribosomes with them as they replicate and are therefore "studded" in ribosomes
41
What is the transmission and the presenting disease with reovirus?
What are the different types of Reoviridae?
- fecal-oral, respiratory and common cold
| - reovirus, rotavirus, and CTFV
42
What is the transmission and the presenting disease with Rotavirus?
- Fecal-oral and gastroenteritis no blood or pus.
43
How do you differentiate between Norwalks and rotatvirus?
Both are gastroenteritis pathogens but if the patient can walk its Norwalk and if they can't than its rotavirus. Age
44
What are the disease manifestation associated with orthomyoxoviridae?
What species does influenza A infect?
What species does influenza B infect?
- Influenzavirus A and B
- infects people and animals
- infects just people
45
What 2 proteins does the orthomyoxoviridae envelope have?
- Hemagglutinin - binds to N-acetylneuraminic acid (sialic acid) and entry into cells
- Neuraminidase - liquefies mucous, and removes sialic acid to free virus.
- allows these viruses to evolve via antigenic shift and drift
46
Antigenic shift?
How?
What does it result in?
- genetic mutation (random shuffling)- replaced with a new virus. Occurs quickly and can spread rapidly due to lack of antibodies against it
- 2 viruses in the same cell, can occur due to lack of proofreading activity in RNA viruses
- Occurs in flu and only result in PANDEMICS
47
Antigenic drift?
- Small changes in the amino acid sequence of Ha and NA - occurs yearly
- Occurs in EPIDEMICS
48
What group is most at risk of death in orthomyxoviridae?
| What is the main mechanism of action?
- Elderly, and children most likely to develop influenza
- No viremia - but intense inflammatory response in the respiratory tract due to killed epithelia -confined to respiratory tract- symptoms for about 1 week. Can lead to secondary bacterial infections.
49
Why should you not give children aspirin with influenzae A or B?
cause of Reyes
50
What are the 3 viruses associated with Paramyxoviridae?
| What does paramyxoviridae induce?
- Morbillivirus- measles
Paramyxovirus - Parainfluenza
Pneumovirus - Respiratory Synctial virus
- cell to cell fusion resulting in synctia formaltion
51
What are the key symptoms of morbillivirus (measles)?
- high fever that develops into maclopapular rash (BELOW THE EARS), cough conjunctivitis, Coryza (3 C's), Photophobia, Koplick spots appear after 2 days (oral mucosa)
52
How does measles spread?
| What is the vaccine for measles?
- respiratory droplets before and after the onset of symptoms
- Live attenuated vaccine - MMR
53
What is the late sequela for Measles?
- occurring 10-15 years post infection - Subacute Sclerosing pan encephalitis (SSPE)- really rare
54
What characteristic symptom is Parainfluenzae associated with?
How is parainfluenzae transmitted by?
- CROUP due to severe lower respiratory traction infection in infants and young children. Other symptoms are because virus stayed in upper respiratory tract --> bronchiolitis and pneumonia
- Parainfluenzae transmitted by respiratory droplets
55
How fast do the symptoms in children resolve in parainfluenzae?
What is another key diagnostic factor found with parainfluenza?
Recovery within 48 hours
| - syncytia
56
What is the characteristic symptoms of Mumps?
| How is mumps spread?
- Bilateral parotid swelling virus can spread via viremia to testes (ORCHIDITIS--> sterility), ovary, pancreas, thyroid, swelling of ostium of Stenson's duct. Begins as respiratory
- Respiratory droplets - person to person
57
Diagnostic for mumps?
| Vaccine?
- Giant multinucleated cells in cell culture
| - MMR
58
What is the most frequent cause of fatal respiratory tract infection in infants and young children?
Respiratory Syncytial virus (RSV) - infected by age 4 mucous plugs block airway--> death
59
Transmission of RSV?
| RSV symptoms?
- transmitted on hands by fomites and respiratory routes
- Symp: upper respiratory tract infection (rhinorrhea *); lower respiratory tract infections: bronchiolitis, air trapping and decreased ventilation
