Virology Flashcards
1
Q
a. What are the Picornaviruses?
b. What kind of virus are they?
A
a. HAV, Enteroviruses (Polio, Coxsackie A/B, Echovirus) and Rhinovirus
b. ss naked + linear RNA virus
2
Q
How are Picornaviruses spread?
A
Fecal oral (Except Rhinovirus)
3
Q
a. What is the pathology of Poliovirus?
b. What is the clinical course of Poliovirus?
A
a. Enters GI tract, replicates in lymphoid tissues like Peyer’s patches, spread to anterior horn of LMN bodies (2-3 weeks after infection)
b. Causes asymmetric paralysis, myalgia, decreased deep tendon reflexes, respiratory insufficiency
4
Q
What are the two vaccines available for Poliovirus?
A
- Salk - inactivated vaccine given parenterally (only forms IgG)
- Sabin - live attenuated given orally (forms IgG AND IgA Abs)
5
Q
What diseases do Coxsackie virus A cause?
A
- Hand, foot, mouth disease (red vesicular rash)
2. Aseptic meningitis infection in summer
6
Q
What diseases do Coxsackie virus B cause?
A
- Dilated cardiomyopathy
2. Devil’s grip, pleurodynia, Bornholm’s disease
7
Q
Which viruses are SS + linear?
a. naked
b. enveloped
A
a. picornaviruses (echo, coxsackie, polio, rhino, HAV), hepevirus, calicivirus
b. flavivirus, togaviruses, retroviruses, coronaviruses
8
Q
Where do + RNA viruses replicate?
A
In the cytoplasm
9
Q
What Calicivirus causes gastroenteritis?
A
Norovirus
10
Q
Norovirus
a. Where are infections common?
b. Causes?
A
a. Outbreaks with lots of people in close quarters (cruises, young kids in daycare), consumption of shellfish/buffets
b. Causes explosive diarrheal illness
11
Q
What are the Flavivirus viruses?
A
HCV
Yellow fever
Dengue fever - break bone fever, thrombocytopenia, renal failure
West Nile virus - encephalitis, flaccid paralysis, seizures, coma
12
Q
a. What kind of virus is Togavirus?
b. What are examples of Togaviruses?
A
a. ss + RNA virus, enveloped
b. Rubella, Western/Eastern Equine Encephalitis
13
Q
What is the clinical disease caused by Rubella
A
- Postauricular and occipital lymphadenopathy
- Arthralgia and arthritis (adults)
- Descending maculopapular rash that starts on face; 3 days (kids)
- Congenital Rubella
14
Q
What are symptoms of congenital Rubella?
A
Sensorineural deafness
Congenital cataracts
PDA
(Jaundice, blueberry muffin rash)
15
Q
a. What is Coronavirus?
b. What illnesses does it cause?
A
a. SS + RNA, enveloped (helical)
b. SARS, MERS, common cold
16
Q
What are the 3 structural genes of HIV and what do they code for?
A
- env (gp120 and gp41) - formed from cleavage of gp160 to form envelope glycoproteins; gp120 mediates attachment to CD4 T cells and gp41 mediates fusion and entry
- gag (p24) - capsid protein
- pol - reverse transcriptase, aspartate protease, integrase
17
Q
a. What kind of virus is HIV?
b. How does it enter host?
A
a. Retrovirus; ss + RNA virus, enveloped (reverse transcriptase synthesizes dsDNA from genomic RNA and ds DNA integrates into host)
b. Virus binds CC45 on macrophages (early) or CXCR4 on T cells (late)
18
Q
How is diagnosis of HIV made?
A
Screening test - ELISA
Confirmatory test - Western blot
19
Q
How is diagnosis of HIV made in babies? Why?
A
PCR; ELISA/Western blots are often falsely positive initially in babies born to infected mothers because gp120 can cross the placenta
20
Q
a. What bug causes Rocky Mountain Spotted Fever?
b. What is the vector?
c. What other bug can be transmitted by the same vector?
A
a. Rickettsia rikettsii
b. Tick (Dermacenter - dogtick)
c. Francisella tularensis (lymphadenopathy, site specific ulcer, granuloma formation)
21
Q
What vector transmits the following diseases and what do they cause?
a. Trypanosoma cruzi
b. Yersinia pestis
c. Plasmodium vivax
d. Leishmania donovani
A
a. Reduviid bug; Chagas disease
b. Flea; Plague
c. Mosquito; malaria
d. Sandfly; Visceral leishmaniasis
22
Q
What species/diseases does the Ixodes tick transmit?
A
- Anaplasma phagocytophilum - human granulocytic anaplasmosis
- Borrelia burgdorferi - Lyme disease
- Babesia microti -
23
Q
Which stain do you use for each of the following?
a. Cryptococcus neoformans
b. Pneumocystis jirovecii
c. Chalmydia
A
a. India ink
b. Silver stain
c. Giemsa stain
24
Q
What kind of virus is Orthomyxovirus?
A
Negative sense ss RNA (has 8 segments); enveloped
25
What are the four segmented viruses?
```
Orthomyxovirus
Bunyavirus
Arenavirus
Reovirus
(BOAR)
```
26
Why is it important if virus is segmented?
A segmented virus can undergo reassortment and genetic shift to cause pandemics
27
What is Hemagglutinin? What is it's role? (HA)
It is a protein that binds sialic acid in the upper respiratory tract or on RBCs that promote viral entry
It causes RBCs to clump together
Seen in influenza virus; the subtype (H1, H2, H3) determines the type of cells it can bind to (determines cell tropism)
28
What is role of M2 protein of influenza?
It is a protein channel that creates the proper pH for viral uncoating; only found on Influenza A
29
What is the mechanism of Amantadine/Rimantadine?
Inhibit M2 so that viral uncoating cannot happen; not used for influenza anymore
30
What is the function of Neuraminidase? (NA)
It cleaves the sialic acid to release the newly formed virus particles from the host cell
31
What is mechanism of Oseltamivir?
NA inhibitor; prevents release of viral progeny
32
enveloped ss - RNA virus, non-segmented
Paramyxovirus
33
Parmyxovirus viruses
Parainfluenza
RSV
MEasles
Mumps
34
4 C's of Rubeola (Measles)
Cough
Coryza
Conjunctivitis
Koplik spots - white spots on buccal mucosa
35
What kind of vitamin can reduce measles mortality in malnourished children?
Vitamin A
36
What is Subacute Sclerosing Pancencephalitis?
Presentation?
Treatment?
Late complication of measles infection
Inflammation and sclerosing of brain caused by persistent measles infection
6 year interval between symptom development; presents as behavioral changes, clumsiness, involuntary jerky movements, seizures, coma, death
No treatment
37
Symptoms of Mumps
```
Parotitis
Orchitis (inflammation of testis) --> can cause sterility
aseptic Meningitis
Meningitis
POM
```
38
Where does mumps replicate?
| What kind of virus is it?
In the parotid glands - or in the CNS
| Paramyxovirus (enveloped ss - RNA)
39
Virus that causes Croup
| Symptoms of Croup
Paramyxovirus (enveloped ss - RNA)
| Seal-like barking cough, inspiratory stridor
40
X-ray finding for Croup
Steeple sign (from narrowing of trachea and subglottis)
41
Virulence factor of all Paramyxoviruses
Fusion protein --> causes respiratory epithelial cells to fuse and form multinucleate cells
42
Pallivizumab
monoclonal antibody against F protein that prevents pneumonia caused by RSV infection in premature infant
43
Most common cause of pneumonia and bronchiolitis in infants
RSV (Paramyxovirus; enveloped ss - RNA)
44
Rhabdovirus
enveloped ss - RNA that causes Rabies virus
45
Cytoplasmic inclusions in neurons infected by Rabies virus
Negri bodies
46
Shape of Rhabdovirus envelope
Bullet shaped
47
Progression of Rhabdovirus
Fever, malaise --> agitation, photophobia, hydrophobia, hypersalivation --> paralysis, coma --> death
48
Pathogenesis of Rhabdovirus
Binds to Nicotinic Ach receptors and travels to CNS by migrating in retrograde fashion up nerve axons; initial infection happens in post synaptic motor endplate
49
Replication and Infection of Rhabdovirus
Incubation period of weeks to months; depends on distance of original infection from CNS
50
Where are Negri bodies found?
Purkinje cells of cerebellum and hippocampal neurons in Rhabdovirus (Rabies) infection
51
Filovirus
Enveloped ss - RNA virus (helical capsule)
| Causes Ebola/Marburg hemorrhagic fever
52
Filovirus targets which types of cells?
Presentation?
What can it progress to?
Targets endothelial cells, phagocytes and hepatocytes
Presents with abrupt onset of flu-like symptoms, diarrhea/vomiting, high fever, myalgia
Can progress to DIC, diffuse hemorrhage, shock
53
What kind of virus is Bunyavirus?
Enveloped ss - RNA virus (3 segments)
54
Where does Bunyavirus get it's envelope from
Golgi body complex of host cells
55
What kind of virus is Hanta virus?
Bunyavirus
| Enveloped, ss - RNA (3 segments)
56
What is the vector of Hanta virus?
Deer mouse
57
What are symptoms of Hanta virus?
Pulmonary edema via capillary leak
Pre-renal azotemia
Hemorrhagic fever
58
What are other Bunyaviruses? What are they transmitted by?
California encephalitis and Rift Valley fever - transmitted by Aedes mosquito
Hantavirus - transmitted by deer mouse
59
What kind of virus is Arenavirus?
Enveloped, SS - circular RNA (2 segments)
| BOAR = Segmented viruses = Bunyavirus, Orthomyxovirus, Arenavirus, Reovirus
60
How are Arenaviruses spread?
By rodents
61
What diseases does Arenavirus cause?
Lymphocytic choriomeningitis virus -> febrile, meningoencephalitis
62
How can you inactivate Arenavirus?
Heating, low pH, detergent, irradiation
63
What kind of virus is Reovirus?
NAKED DS RNA (10-12 segments)
64
#1 cause of fatal diarrhea in children
Rotavirus (a Reovirus = DS RNA virus)
65
How is Rotavirus transmitted? What does it cause?
Transmitted fecal-oral route
| Exposive, watery diarrhea caused by toxin
66
What does the Rotavirus toxin do?
Toxin = NSP4 enterotoxin
| Increases Chloride permeability --> secretory diarrhea
67
What is classic time of year for Rotavirus outbreak? In which population
Winter; especially in day care centers, kindergartens
68
What is a S/E of the Reovirus vaccine?
| When is vaccine given?
Intussusception - telescoping of bowel
| Before 3 months of age
69
What is a S/E of the Reovirus vaccine?
| When is vaccine given?
Intussusception - telescoping of bowel
| Before 3 months of age
70
What kind of virus is EBV?
Herpesviruses ds DNA, enveloped
| HHV-4
71
What kind of virus is EBV?
Herpesviruses ds DNA, enveloped
| HHV-4
72
What are symptoms of EBV Mononucleosis?
Fevere
HepatoSPLENOMEGALY (from T cell proliferation)
Lymphadenopathy (especially POSTERIOR CERVICAL)
73
How is EBV transmitted?
Respiratory secretion and saliva
74
What cells does EBV infect?
Infects B cells through CD21 but then causes proliferation of reactive cytotoxic T cells (Downey cells) trying to control infection
75
How is EBV detected?
+ Monospot Test (heterophile Abs detected by agglutination of sheep or horse RBCs)
76
What are associations of EBV?
Nasopharyngeal carcinoma (tumor of Asians)
B cell lymphoma (endemic Burkitt lymphoma in jaw, sporadic Burkitt lymphoma in ileocecum, with t(8;14))
Oral Hairy Leukoplakia seen in patients with HIV, not precancerous
77
What are associations of EBV?
Nasopharyngeal carcinoma (tumor of Asians)
B cell lymphoma (endemic Burkitt lymphoma in jaw, sporadic Burkitt lymphoma in ileocecum, with t(8;14))
Oral Hairy Leukoplakia seen in patients with HIV, not precancerous
78
What are the TORCHeS infections?
```
Toxoplasma
Other (VZV, Parvo)
Rubella
CMV
HIV, Herpes
Syphilis
```
79
What are the TORCHeS infections?
```
Toxoplasma
Other (VZV, Parvo)
Rubella
CMV - most common fetal viral infection
HIV, Herpes
Syphilis
```
80
What are the TORCHeS infections?
```
Toxoplasma
Other (VZV, Parvo)
Rubella
CMV - most common fetal viral infection
HIV, Herpes
Syphilis
```
81
Congenital CMV Infection
Blueberry muffin rash from thrombocytopenia
Jaundice
Hepatosplenomegaly
Sensorineural hearing loss
Intracranial calcifications --> seizures, mental retardation
82
Congenital CMV Infection
Blueberry muffin rash from thrombocytopenia
Jaundice
Hepatosplenomegaly
Sensorineural hearing loss
Intracranial calcifications --> seizures, mental retardation
(Congenital CMV is more likely to be asymptomatic)
83
Congenital CMV Infection
Blueberry muffin rash from thrombocytopenia
Jaundice
Hepatosplenomegaly
Sensorineural hearing loss - develop hearing loss later in life
Intracranial calcifications --> seizures, mental retardation
(Congenital CMV is more likely to be asymptomatic - 80-90%)
84
Which trimester is associated with highest risk of Congenital CMV?
Second trimester
| Hydrops fetalis = heart failure --> severe edema ---> leads to spontaneous abortion
85
Which trimester is associated with highest risk of Congenital CMV?
Second trimester
| Hydrops fetalis = heart failure --> severe edema ---> leads to spontaneous abortion
86
#1 cause of mental retardation from congenital viral infection
CMV
87
#1 cause of sensorineural hearing loss in infants
CMV
88
Organ transplant patients at risk of developing which CMV infection?
Pneumonia
89
Organ transplant patients at risk of developing which CMV infection?
Pneumonia
90
When are HIV patients at risk of CMV infections?
With CD4 counts
91
What is common CMV disease in HIV patients?
AIDS retinitis (vision loss, flashing lights, etc - usually unilateral)
92
What is common CMV disease in HIV patients?
AIDS retinitis (vision loss, flashing lights, etc - usually unilateral)
93
CMV vs. Herpes esophagitis
CMV - singular, deep and linear
| Herpes - multiple and shallow
94
CMV vs. Herpes esophagitis
CMV - singular, deep and linear
| Herpes - multiple and shallow
95
Treatment for CMV
Ganciclovir
96
Treatment for CMV
Ganciclovir - first line
| Fascarnet - second line (when virus has UL97 gene mutation that makes it resistant to Ganciclovir)
97
Treatment for CMV
Ganciclovir - first line
| Fascarnet - second line (when virus has UL97 gene mutation that makes it resistant to Ganciclovir)
98
How do you distinguish CMV and EBV?
CMV has (-) monospot test
99
What is the characteristic looking cell in CMV?
Owl eye inclusions
100
How do you transmit CMV?
```
Congenitally
Transfusion
Sexual Contact
Saliva
Urine
Transplant
```
101
Where is CMV latent?
In mononuclear cells (T, B, macrophages)
102
What kind of virus is CMV?
Herpesvirus - Enveloped, ds DNA (HHV-5)
103
What kind of virus is CMV?
Herpesvirus - Enveloped, ds DNA (HHV-5)
104
What is Congenital Varicella syndrome?
Limb hypoplasia
Cutaneous scarring in dermatomal pattern
Blindness
105
What virus is responsible for Roseola?
HHV6 (also called Exanthema subitum)
106
What characterizes Roseola illness?
High fevers for several days that can cause seizures, followed by a diffuse macular rash
Affects children ages 6 months - 2 years
107
What does the rash of Roseola look like?
Diffuse macular rash that has lacy appearance and spares the face
108
What virus is responsible for Kaposi sarcoma?
HHV-8 (enveloped, DS DNA)
109
Which patients does Kaposi sarcoma commonly affect?
HIV/AIDS, transplant patients
| Seen in old Russian men and African patients
110
What does Kaposi sarcoma look like?
Dark/violaceous plaques/nodules on nose, extremities or mucous membranes (most commonly HARD PALATE)
Also affects GI tract and lungs
111
What is the pathophysiology of Kaposi sarcoma plaques?
They represent vascular proliferations from the virus causing dysregulation of VEGF
112
How is HHV8 (Kaposi sarcoma) transmitted?
By sexual contact (includes kissing)
113
What diseases does Polyomavirus cause?
JC virus - progressive multifocal leukoencephalopathy in HIV
| BK virus - transplant patients, commonly targets kidney
114
What is JC virus?
A polyomavirus (naked ds DNA) that causes PML in HIV patients; they are non-enhancing ring lesions caused by demyelination
115
What is BK virus?
A polyomavirus (naked ds DNA) that causes hemorrhagic cystitis in transplant patients
116
What is the only ss DNA virus?
Parvovirus
117
What kind of virus is Papillomavirus?
Naked ds DNA
118
Diseases caused by HPV 1-4
Verruca vulgaris (cutaneous wart)
119
Diseases caused by HPV 6, 11
1) Laryngeal papillomatosis (recurrent respiratory papillomatosis) - tumors in airway, seen in kids from transmission during birth
2) Anogenital warts - sexually transmitted
120
Diseases caused by HPV 16, 18, 31, 33
Anogenital cancers (squamous cell carcinoma)
121
HPV Vaccine
Gardasil
| Inactivated subunit vaccine against HPV 6, 11, 16, 18
122
Pathogenesis of HPV
Disrupts cell cycle -->
- E6 degrades p53 and removes break from transition from G1 --> S phase
- E7 degrades Rb (tumor suppressor)
123
Most common STD
HPV
124
Post coital bleeding
Think cervical cancer
125
ss DNA virus
Parvovirus
126
How is Parvovirus spread?
By respiratory droplets
127
Parvovirus disease in children and adults
Children - Slapped cheeks rash
Adults - arthritis and edema
Sickle cell patients - Aplastic crises
128
Causes RBC destruction in fetus that leads to hydrops fetalis and death
Parvovirus B19 (smallest DNA virus, single stranded)
129
NAKED ss DNA virus
Parvovirus
130
Causes RBC destruction in fetus that leads to hydrops fetalis and death
Parvovirus B19 (smallest DNA virus, single stranded)
131
What diseases does Adenovirus cause?
Conjunctivitis
Hemorrhagic cystitis
Pharyngitis, sore throat
Pneumonia
132
What diseases does Adenovirus cause?
Conjunctivitis
Hemorrhagic cystitis
Pharyngitis, sore throat
Pneumonia
133
What kind of virus is Adenovirus?
Naked, double stranded DNA virus
134
What kind of virus is Adenovirus?
Naked, double stranded DNA virus
135
How is Adenovirus transmitted?
Fecal oral transmission
136
Who is commonly infected with Adenovirus?
Military recruits
Kids in daycare
People swimming in public pools
137
How is Adenovirus transmitted?
Fecal oral transmission or by respiratory droplets
138
Who is commonly infected with Adenovirus?
Military recruits
Kids in daycare
People swimming in public pools
139
Who can be given an Adenovirus vaccine? What kind of vaccine is it?
Military recruits are given a live attenuated vaccine
140
Who can be given an Adenovirus vaccine? What kind of vaccine is it?
Military recruits are given a live attenuated vaccine
141
Enveloped Double Stranded DNA virus (LARGEST)
Poxvirus
142
Enveloped Double Stranded DNA virus (LARGEST)
Poxvirus
143
B cytoplasmic inclusions (Guarnierni)
Sites of viral replication of Poxvirus
144
B cytoplasmic inclusions (Guarnierni)
Sites of viral replication of Poxvirus
145
Where does Poxvirus replicate?
In the cytoplasm because it contains everything it needs - it makes it's own envelope and it has a DNA dependent RNA polymerase
146
Where does Poxvirus replicate?
In the cytoplasm because it contains everything it needs - it makes it's own envelope and it has a DNA dependent RNA polymerase
147
Flesh colored papule with central umbilication
Molluscum contagiosum (caused by Poxvirus)
148
Flesh colored papule with central umbilication
Molluscum contagiosum (caused by Poxvirus)
- Spread by sexual contact in adults (single papule)
- In kids, multiple papules on trunk
149
What kind of virus is Hepatitis B?
Enveloped, partially DS DNA virus
150
Enveloped DNA viruses
Herpesviruses
Hepadnavirus (Hepatitis B)
Poxvirus
151
Non-enveloped DNA viruses
Adenovirus
Parvovirus (single stranded)
Papillomavirus
Polyomavirus (JC and BK)
152
Transcription of HBV genome
Starts as partially DS DNA virus --> ss RNA --> ds DNA
| Carries reverse transcriptase and does NOT integrate into host chromosome like HIV
153
Transcription of HBV genome
Starts as partially DS DNA virus --> ss RNA --> ds DNA
| Carries reverse transcriptase and does NOT integrate into host chromosome like HIV
154
How is HBV transmitted?
Sex and blood
155
Associations of HBV (3)
1. Polyarteritis nodosa - purpuric rash with non-blanching dark merciless, arthralgia and kidney damage (vasculitis)
2. Membranous glomerulonephritis (thickened BM)
3. Membranoproliferative glomerulonephritis (tram track)
156
Which liver enzyme is higher in viral hepatitis?
ALT
157
How is HBV transmitted?
Sex and blood, perinatally
158
Which liver enzyme is higher in viral hepatitis?
ALT
159
What is given to babies of moms infected with HBV?
Immunoglobulin AND the HBV vaccine
