Virology: Exam 1 Flashcards
1
Q
What is a virion and what is it composed of?
A
infectious particle composed of nucleic acids, protein capsid, and envelope
2
Q
What is a virus?
A
generic term for any and all aspects of a viral pathogen at any stage of development
3
Q
What is VZV and what disease is caused by it?
A
Varicella zoster virus which causes chicken pox
4
Q
What is the main symptom of a VZV infection?
A
itchy, blister-like rash
5
Q
What type of virus is VZV?
A
Herpesvirus (DNA)
6
Q
What type of virus is herpesvirus?
A
DNA virus
7
Q
What is herpes zoster known as?
A
Shingles
8
Q
What does the primary vs recurrent VZV infection cause?
A
Primary infection results in varicella (chickenpox)
Recurrent infection results in herpes zoster (shingles)
9
Q
What is varicella also known as?
A
chicken pox
10
Q
What is the general survival time of VZV in the environment?
A
short survival
11
Q
90% of primary varicella infections occur at what age and between what ages is the maximum incidence rate?
A
Occurs at <10 years of age and max between 1-6 years of age
12
Q
What is the varicella reservoir?
A
Human
13
Q
How is varicella transmitted?
A
- Airborne droplet
- Direct contact with lesions
14
Q
When does varicella peak throughout the year?
A
in the winter and early spring
15
Q
What is the household transmission rate vs transmission rate with secondary contacts of varicella?
A
> 90% household transmission
10-35% secondary transmission
16
Q
In varicella, when can a host start to spread the infection and until when?
A
1-2 days before onset of rash and out to 4-5 days after onset
17
Q
What is the incubation period in varicella and what is the average range?
A
10-21 days with an average of 14-16
18
Q
What is the incubation period in varicella patients treated with immunoglobulins?
A
up to 28 days
19
Q
Who is at higher risk of developing herpes zoster?
A
healthy children infected with VZV during infancy
20
Q
What are complications in shingles?
A
postherpetic neuralgia
myelitis
small vessel encephalitis (immunocompromised)
large vessel granulomatous arteritis (immunocompetent)
21
Q
VZV virion components
A
- lipid envelope
- tegument
- nucleocapsid
- dsDNA genome
- glycoprotein spikes
22
Q
What types of viruses are alpha herpes viruses and what do they lead to?
A
dsDNA viruses which lead to human infection and latency in dorsal root ganglia
23
Q
List the three types of alphaherpes viruses
A
- HSV-1
- HSV-2
- VZV
24
Q
List the three types of betaherpes viruses
A
- CMV
- HHV-6
3.HHV-7
25
What is a common gammaherpes virus?
EBV
26
What is herpesvirdae?
family of DNA viruses that cause latent infection
27
How is VZV transmitted?
1. air
2. formites
3. Direct contact
28
How does VZV enter the body?
through mucuous membranes
29
where does VZV replicate?
regional lymph nodes
30
how soon does viremia occur after initial VZV infection?
4-6 days after infection
31
in VZV, what does viremia result in?
replication in other organs (liver, spleen, sensory ganglia)
32
In VZV, when does secondary viremia appear and how is it expressed?
after day 14 and expressed as skin infection with characteristic rash
33
Where does VZV become latent?
in ganglia
34
What is the difference between herpes zoster and zoster sine herpete?
zoster sine herpete produces pain but without a rash
35
What is VZIG and who receives it?
varicella post-exposure prophylaxis given to individuals at hight risk
1. either with varicella 5 days before to 2 days after delivery
2. immunocompromised
36
List all of the dsDNA viruses
1. Poxviridae
2. Adenoviridae
3. Herpesviridae
4. Papillomaviridae
37
What viruses fall into the poxviridae family?
smallpox (varieola)
Monkeypox
38
What viruses fall into the Adenoviridae family?
adenovirus
39
What viruses fall into the Herpesviridae family?
HSV-1
HSV-2
CMV
EBV
VZV
HHV 6, 7, 8
40
What viruses fall into the papillomaviridae family?
HPV
41
What is the structure of an adenoviridae virus?
naked icosahedral dsDNA
42
What are the common adenoviridae serotypes?
1 to 8, 11, 21, 35, 37, 40
43
What infections are caused by adenoviridae?
1. pneumonia
2. gastroenteritis
3. keratoconjunctivitis
4. acute hemorrhagic cystitis
5. pharyngoconjunctival fever
44
Which adenoviridae serotypes are most commonly associated with respiratory illness and which is most severe?
3, 4, and 7 (most severe)
45
Which adenoviridae serotypes cause epidemic keratoconjunctivitis?
8, 19, 37, 53, and 54
46
Which adenoviridae serotypes are enteric and cause gastroenteritis?
40 and 41
47
Which adenoviridae serotypes can be transmitted in bodies of water and cause febrile disease and conjunctivitis?
4 and 7
48
What is the structure of herpesviridae?
enveloped dsDNA
49
How many species of herpesviridae are there and what are they?
eight species
1. HSV-1
2. HSV-2
3. VZV
4. EBV
5. CMV
6. Human herpesvirus-6
7. Human herpesvirus-7
8. Human herpesvirus-8
50
which species of herpesviridae is kaposi's sarcoma herpes virus?
HHV-8
51
What is the mortality rate of HSV encephalitis and which species is most prevalent in neonates vs adult?
70%
HSV-1 in adults
HSV-2 in neonates
52
What is the causative agent of variety of warts and tumors in respiratory, GI, and genital tracts?
HPV
53
what type of vaccine is the HPV vaccine and which types does it protect against?
quadrivalent against type 6, 11, 16, and 18
54
Why is serology not helpful in diagnosing HSV?
there is a high prevalence of HSV antibodies in population
55
Where does EBV establish latency?
in B cells
56
What is the primary EBV infection?
infectious mononucleosis
57
What can cause EBV reactivated?
B cell lymphoma
Lymphoproliferative
58
what can an immunosuppressed patient with CMV develop?
retinitis and enteritis
59
What is a Karposi's sarcoma?
HHV-8 which causes BV tumor in AIDS patients
60
which viruses cause latent infections?
herpesviruses
human retroviruses
human papillomavirus
61
Oncogenic associations of EBV?
lymphoma
nasopharyngeal carcinoma
leiomyosarcoma
62
Oncogenic associations of Herpesvirus-8?
Kaposi's sarcoma
B-cell lymphoma of body cavities
63
Oncogenic associations of Hepatitis B and Hepatitis C viruses?
Hepatocellular carcinoma
64
Oncogenic associations of human papillomavirus?
cervical cancer
rectal/anogenital carcinoma
65
What is the herpesvirus structure in primary infection vs latency?
linear dsDNA virus
linear in mature virion
circular in latent form
66
What is human papillomavirus also known as?
Papovavirus
67
What is the most common viral STD?
HPV
68
What the the structure of HPV virion?
dsDNA virus with genome entirely sequenced
69
What is HPV type defined by?
DNA sequence
70
Which HPV types are plantar and common warts?
1,2
71
Which HPV type is associated with condylomata and laryngeal warts?
6,11
72
Which HPV type is associated with anogenital malignancies?
16,18
73
What causes an increased risk of developing cervical cancer?
1. early age of intercourse
2. Number of sexual partners
3. Smoking
4. Lower socioeconomic status
5. high-risk male partner
6. STDs
74
Which HPV type is responsible for 90% of genital warts?
6 and 11
75
Which HPV type is responsible for 70% of cervical cancers?
16 and 18
76
Hepatitis A route of transmission?
fecal/oral, contaminated food/oral
77
Hepatitis B route of exposure?
blood, semen, mother-child
78
Hepatitis C route of exposure?
Blood (IV drug use, transfusion, sexual intercourse, etc.)
79
Hepatitis D route of transmission?
Survive only in cells co-infected with hepatitis B
80
Hepatitis E route of transmission?
fecal/oral, contaminated food/water
81
Which hepatitis types are there vaccines for?
Hepatitis A and B
82
Which hepatitis causes short-term disease and is not a chronic carrier state?
Hepatitis E
83
Which types of hepatitis are associated with an increased risk of HCC?
Hepatitis B and C
84
Which hepatitis is the most common chronic blood borne infection in the US?
Hepatitis C
85
What type of specific virus is Hepatitis C?
flavivirus
86
The is the virion structure of Hepatitis C?
enveloped ssRNA virus
87
Where does hepatitis C replicate?
In the liver cells, lymphocytes, and monocytes
88
How many progeny/day does hepatitis C replicate?
> 1 trillion progeny/day
89
Which hepatitis mutates rapidly and why?
Hepatitis C due to error-prone RNA polymerase
90
What is the mechanism of Hepatitis C?
Down regulates stimulatory receptors on NK cells
Increases inhibitory receptors on NK and CD+ killer cells
Produces TGF-beta, which blocks activation of T cells and inhibits production of IFN-gamma
91
What are other examples of Flavivirus other than Hepatitis C?
Dengue
West Nile
Yellow Fever
Zika
92
How many genotypes and subtypes does Hepatitis C have?
Six major genotyped and >15 subtypes
93
How is heterogeneity involved in the transmission of Hepatitis C?
The polymerase lacks proofreading capability resulting in many mutations and significant viral diversity which allows escape from host immune system and medications as well as vaccines
94
What does the prozone phenomenon refer to?
to the absence of antibody-antigen precipitation
95
What is the prozone?
the prozone reaction refers to the absence of antibody-antigen precipitation in the presence of antibody excess
96
What is the postzone?
the absence of precipitation with excess antigen. Term is applied to false-negative antigen test results in undiluted serum, which become positive on dilution
97
What is the zone of equivalence?
the point of maximum precipitation
98
what increases the risk of chronic HCV?
illicit drug use
male gender
black race
low income family
10 lifetime sexual partners
Incarceration
99
Main transmission for all hepatitis types
Hepatitis A = fecal/oral
Hepatitis B = blood/sexual
Hepatitis C = blood
100
Which Hepatitis types can be transmitted perinatally?
Hepatitis B and C
101
Which hepatitis involves spontaneous resolution and chronic infection and at what percent?
hepatitis C chronic (85%) and spontaneous (15%) resolution
102
What type of virus is picornaviruses?
non enveloped, icosahedral capsid, ssRNA, linear
103
Where do picornaviruses replicate?
in the cytoplasm of the cell
104
What type of viruses are in the picornavirus family?
enteroviruses (polio)
rhinoviruses (common cold)
hepatovirus (hepatitis A)
105
What is an example of enterovirus?
polio virus
106
Which enzymes are found within hepatocytes and when are they released?
ALT and AST which are released when liver cells are damaged
107
Which liver enzyme is specific for liver injury?
ALT
108
Which liver enzyme is also found in skeletal and cardiac muscles?
AST
109
In what diseases is AST a predominant biomarker?
in alcohol-related liver disease and cirrhosis
110
What is classified as severe AST and ALT elevation?
>15x
111
What are the two main conditions causing severe AST and ALT elevation?
acute viral hepatitis
ischemic hepatitis
112
Where is alkaline phosphatase found in the body?
hepatocytes that line the bile canaliculi
113
What is elevated in a biliary obstruction and why?
alkaline phosphatase which stretched the bile canaliculi
114
Other than hepatocytes, where can alkaline phosphatase be found in the body?
bone and placenta
115
Where is GGT found?
bile cancaliculi
116
Why is GGT not specific for identifying obstructions?
it can be elevated by drugs/toxins
117
What is bilirubin?
water insoluble product of heme metabolism
118
What happens to bilirubin once it enters the liver and why?
it is conjugated to become water soluble so it can excreted in bile and into bowel
119
What is indirect vs direct bilirubin?
indirect billirubin is non-conjugated whereas direct is conjugated
120
What is an example of prehepatic disease and what type of bilirubin is elevated?
hemolysis which elevated indirect bilirubin
121
What is an example of hepatic disease and what type of bilirubin is elevated?
viral infection which increases direct and indirect bilirubin
122
What is an example of post hepatic disease and what type of bilirubin is elevated?
Gallstones which increases direct bilirubin
123
What condition results in dark (foamy) and pale stool?
gallstones
124
What two tests are true tests of liver function?
prothrombin time/INR
Albumin
125
What does prothrombin time/INR measure?
vitamin K dependent clotting factors (factor II, VII, IX, X)
126
Why aren't clotting factors produced when there is liver damage?
the liver is involved in a captivating vitamin K
127
What two conditions cause albumin to drop rapidly?
acute illness and nephrotic syndrome
128
What kind of damage does elevated AST and ALT indicate?
hepatocellular damage
129
What kind of damage does elevated alkaline phosphatase and Bilirubin indicate?
Cholestatic damage
130
Hepatitis A incubation period
15-50 days (average of 28)
131
Where does hepatitis A replicate and where does it shed?
replicated in the liver and sheds in feces
132
When does Hepatitis A begin to shed in feces?
two weeks before to one week after onset of clinical illness
133
Does hepatitis A result in chronic infection and/or chronic liver disease?
no
134
Who is at an increased risk of developing hepatitis A?
international travelers, child care-givers, patients with chronic liver disease, IV drug users
135
on average, how long do hepatitis A symptoms last?
< 2 months
136
What kind of virus is rotavirus?
naked dsRNA virus
137
What is the most common cause of gastroenteritis in infants and children?
rotaviruses
138
When do most rotavirus outbreaks occur?
winter months in temperate zones and year-round in subtropical and tropical regions
139
what is the route of transmission in rotaviruses?
fecal oral route
140
incubation period of rotaviruses
1-4 days
141
How it is rotavirus diagnosed?
cultures, immunoassays, PCR
142
Why does rotavirus lead to malabsorption of nutrients?
virus can destroy microvilli
143
What is the main cause of death in rotavirus?
dehydration
144
what typeof viruses are norovirus and sapovirus?
ssRNA
145
what type of virus is Ebola virus?
ssRNA
146
what type of virus is yellow fever and dengue virus?
ssRNA
147
What type of virus is coronavirus?
ssRNA
148
what type of virus is West Nile virus and zika virus?
ssRNa
149
what type of virus is influenza A-C?
ssRNA
150
what type of virus is mumps, measles, parainfluenza, and RSV?
ssRNA
151
what type of virus is enterovirus virus?
ssRNA
152
what type of virus is HIV?
ssRNA
153
what type of virus is Hepatitis A-E?
ssRNA
154
what type of virus is rubella?
ssRNA
155
which group of rotavirus is most common in humans?
group A
156
what are rotaviruses composed of?
segmented dsRNA without envelope
157
how is rotavirus transmitted?
fecal oral route
158
What is the most common cause of infectious gastroenteritis in the United States?
norovirus
159
which populations are at risk of getting norovirus?
individuals ins schools, nursing homes, families, cruises/resorts
160
how's norovirus transmitted?
waterborne and person to person
161
what is the infection rate of norovirus?
50%
162
when does illness with norovirus subside?
72 hours
163
How is norovirus diagnosed and what laboratory test cannot be used?
diagnosed wit RT-PCR but cannot be grow in culture
164
How is sapovirus detected?
electron microscopy, RT-PCr, and ELISA
165
symptoms of sapovirus?
diarrhea and vomiting
166
who is most likely to experience symptoms with sapovirus?
infants, young children, and older patients
167
what virus causes 15% of childlike infections in adults?
coronaviruses
168
what do coronaviruses target in the body?
the GI tract
169
why are children less likely to get coronavirus?
higher seroconversion rate in children
170
how is coronavirus transmitted?
direct contact, droplet, airborne, and occasionally in urine and feces
171
why can't corona viruses be cultured?
they are extremely fragile
172
preferred detection methods of coronavirus?
RT-PCR
173
how is yellow fever prevented?
vaccines (required for travel to endemic regions)
174
what causes yellow fever?
mosquito bite (lil bitches)
175
who are the natural hosts of yellow fever?
monkeys
176
who is the natural host of west niles virus and how is it transmitted?
birds and is transmitted via mosquitos
177
how is zika virus transmitted?
mosquito but also via infected blood or sexual contact
178
what molecular methods are used at OSF SFMC to detected SARS CoV-2?
RT-PCR, ForuPLEX, TORCH, and Abbott ID-NOW
179
what did influenza originate as?
zoonotic infection
180
how are enveloped members of influenza distinguished?
by matrix (M) protein and nucleoprotein (NP)
181
whys is influenza virus changing every year?
due to antigenic drift caused by RNA replication of errors of the virus
182
Which types of influenza does antigenic drift occur in?
A, B, and C
183
when does antigenic shift occur?
when surface antigens change drastically
184
which influenza types are associated with antigenic shift?
influenza A
185
What do influenza A and B infect?
mammals and avian species
186
what does influenza C cause?
mild upper respiratory illness in humans
187
What is the causative agent of croup bronchitis, bronchiolitis, and interstitial pneumonia?
RSV
188
what is the most common cause of lower respiratory tract disease among infants and young children?
RSV
189
which virus is associated with nosocomial infections?
RSV
190
what genus is RSV a member of?
pneumovirus
191
how is RSV transmitted?
large particle droplets and formites
192
is there a vaccine for RSV?
no
193
how many parainfluenza viruses are there?
4
194
which types of PIV cause paramyxovirus and rubulavirus?
paramyxovirus = 1 and 3rubulavirus = 2 and 4
195
what is the structure of PIV?
enveloped helical RNA
196
what are the two distinct receptors in PIV?
HN: hemagglutinin-neuramindae
F: fusion antigen
197
what is the primary cause of respiratory disease in young children?
PIV
198
which PIV types cause croup?
1 and 2
199
what is the structure of mumps virus?
enveloped ssRNA virus
200
what are the surfaces antigens in mumps virus?
HN and F surface antigens
201
how is mumps virus transmitted?
droplets of infected saliva
202
causative agent of infectious parotitis?
mumps virus
203
which virus causes swollen parotid glands, swelling of testes, ovaries, pancreas, and potentially permanent sterility?
mumps virus
204
Where are swabs taken from when diagnosing mumps virus?
stensen duct or saliva
205
when are swabs collected in mumps virus?
9 days before until 8 days after parotitis appears
206
Ro of mumps?
8-12
207
What is rubeola virus also known as?
measles
208
what genus does measles virus belong to?
morbillivirus
209
structure of measles virus
ssRNA, enveloped
210
who are the natural hosts of measles?
humans
211
where does initial viral replication occur in measles virus and where does it replicate after?
mucosal cells of respiratory tract and then in the local lymph nodes and spreads systemically
212
measles incubation period
7-10 days
213
does measles cause abrupt symptoms?
yes abrupt onset of sneezing, rhinorrhea, red eyes, and fever
214
what develops 2-3 days after abrupt onset of symptoms in measles?
maculopapular rash on head and trunk, whitish spots, and fever
215
which virus is easily diagnosed clinically without laboratory testing?
measles
216
Ro of measles?
12-18
