13-HERPES Flashcards
(254 cards)
1
Q
What is the virion shape and size of herpesviruses
A
Spherical; 150-200 nm in diameter (icosahedral)
2
Q
What is the genome structure of herpesviruses
A
Double-stranded DNA; linear; 125-240 kbp; reiterated sequences
3
Q
How many proteins are present in a herpesvirus virion
A
Less than 35
4
Q
What is the envelope composition of herpesviruses
A
Viral glycoproteins; Fc receptors
5
Q
Where does herpesvirus replication occur
A
Nucleus; budding from nuclear membrane
6
Q
What are some characteristics of herpesviruses
A
Encode many enzymes; establish latent infections; persist indefinitely; frequently reactivated; some cause cancer
7
Q
What is a unique characteristic of herpesvirus DNA
A
Terminal and internal repeated sequences
8
Q
What is fingerprinting in herpesvirus epidemiology
A
Epidemiologic typing using restriction endonucleases to produce different cleavage patterns
9
Q
What is the tegument in herpesviruses
A
An asymmetric structure between the capsid and envelope
10
Q
Where is the nuclear envelope of herpesviruses derived from
A
The infected cell’s nuclear membrane
11
Q
What is the effect of virion host shutoff
A
Degrades host cell mRNA to compete for resources
12
Q
What is the function of VP16 in herpesvirus replication
A
Protects viral mRNA and acts as a transcriptional activator
13
Q
What is the primary site of infection for HSV-1 and HSV-2
A
Epithelial cells
14
Q
Where do HSV-1 and HSV-2 establish latent infections
A
Neurons
15
Q
What clinical presentation is associated with HSV-1
A
Oropharyngeal lesions; fever blisters; sporadic encephalitis
16
Q
What clinical presentation is associated with HSV-2
A
Genital herpes
17
Q
What diseases does Varicella-Zoster Virus (VZV) cause
A
Chickenpox (varicella) on primary infection; shingles (zoster) upon reactivation
18
Q
What are the symptoms of VZV in adults
A
Serious viral pneumonia
19
Q
Where does Cytomegalovirus (CMV) replicate
A
Epithelial cells of the respiratory tract; salivary glands; kidneys; persists in lymphocytes
20
Q
What diseases are associated with CMV
A
Infectious mononucleosis (heterophile-negative); cytomegalic inclusion disease in newborns; congenital defects; mental retardation
21
Q
Which cells does Human Herpesvirus-6 (HHV-6) infect
A
T lymphocytes
22
Q
What disease is caused by HHV-6
A
Exanthem subitum (roseola infantum)
23
Q
Which cells does Human Herpesvirus-7 (HHV-7) infect
A
T lymphocytes
24
Q
What disease is associated with Epstein-Barr Virus (EBV)
A
Infectious mononucleosis; human lymphoproliferative disorders in immunocompromised patients; Burkitt lymphoma; nasopharyngeal carcinoma; other lymphomas
25
Where does EBV replicate
Epithelial cells of the oropharynx and parotid gland
26
Where does EBV establish latent infections
Lymphocytes
27
What disease is associated with Human Herpesvirus-8 (HHV-8)
Kaposi sarcoma
28
What disease is associated with Herpes B virus of Macaque Monkeys
Severe neurologic diseases
29
Which virus causes Burkitt lymphoma
Epstein-Barr Virus (EBV)
30
Which virus is associated with Kaposi sarcoma
KSHV (Kaposi Sarcoma-associated Herpesvirus)
31
Which virus causes lymphoma in chickens
Marek disease virus
32
Where do herpesviruses establish latency
Neurons; lymphocytes; various tissues
33
How do herpesviruses reactivate from latency
Various stimuli including stress; immunosuppression; UV radiation
34
What are the common modes of transmission for herpesviruses
Direct contact with infected secretions; respiratory droplets; sexual contact; vertical transmission
35
How are herpesviruses diagnosed
Clinical presentation; viral culture; PCR; serology
36
What antiviral drugs are used to treat herpesvirus infections
Acyclovir; valacyclovir; famciclovir
37
How do antiviral drugs like acyclovir work
Inhibit viral DNA polymerase and viral replication
38
What is the role of the tegument in herpesvirus infections
Carries proteins needed for viral replication after cell entry
39
What feature allows herpesviruses to establish lifelong infections
Their ability to establish latency in host cells
40
What are the common characteristics of Alphaherpesviruses
Short reproductive cycle; efficient cell lysis; latency in sensory ganglia
41
What are the common characteristics of Betaherpesviruses
Long reproductive cycle; cytomegalic effect; latency in secretory glands and lymphoid tissue
42
What are the common characteristics of Gammaherpesviruses
Variable reproductive cycle; latency in lymphoid tissue; oncogenic potential
43
Which subfamily does Herpes simplex virus type 1 and 2 belong to
Alphaherpesvirinae
44
What is the growth cycle and cytopathology of Alphaherpesviruses
Short; cytolytic
45
Where do Alphaherpesviruses establish latent infections
Neurons
46
What is the genus of Herpes simplex virus type 1 and 2
Simplexvirus
47
Which subfamily does Varicella-Zoster virus belong to
Alphaherpesvirinae
48
What is the official name of VZV
Human Herpesvirus 3
49
Which subfamily does Cytomegalovirus belong to
Betaherpesvirinae
50
What is the growth cycle and cytopathology of Betaherpesviruses
Long; cytomegalic; long; lymphoproliferative
51
Where do Betaherpesviruses establish latent infections
Glands; kidneys; lymphoid tissue
52
What is the genus of Cytomegalovirus
Cytomegalovirus
53
What is the official name of Cytomegalovirus
Human Herpesvirus 5
54
Which viruses belong to the Betaherpesvirinae subfamily
Cytomegalovirus (HHV-5); Human Herpesvirus 6; Human Herpesvirus 7
55
Which subfamily does Epstein-Barr virus belong to
Gammaherpesvirinae
56
What is the growth cycle and cytopathology of Gammaherpesviruses
Variable; lymphoproliferative
57
Where do Gammaherpesviruses establish latent infections
Lymphoid tissue
58
What is the genus of Epstein-Barr virus
Lymphocryptovirus
59
What is the official name of Epstein-Barr virus
Human Herpesvirus 4
60
Which viruses belong to the Gammaherpesvirinae subfamily
Epstein-Barr virus (HHV-4); Kaposi sarcoma-associated herpesvirus (HHV-8)
61
What is the genus of Kaposi sarcoma-associated herpesvirus
Rhadinovirus
62
What is the official name of Kaposi sarcoma-associated herpesvirus
Human Herpesvirus 8
63
What causes the pathological changes in herpes virus infections
Necrosis of infected cells together with inflammatory response
64
How do lesions induced by HSV in skin and mucous membranes compare to those caused by VZV
They are the same
65
Do primary and recurrent herpes infections cause different types of lesions
No; changes are similar but vary in degree reflecting the extent of viral cytopathology
66
What is an efficient method for cell-to-cell spread of HSV even in the presence of neutralizing antibody
Cell fusion
67
How is HSV entry initiated
By fusion of the viral envelope
68
What happens during viral assembly of HSV particles
Immature enveloped particles fuse with the outer nuclear membrane (de-envelopment)
69
What is syncytium formation in HSV infection
Fusion of infected cells with neighboring cells leading to formation of multinucleated enlarged cells
70
What is required for primary HSV infection to occur
Contact with someone excreting virus; virus must encounter mucosal surfaces or broken skin
71
Are primary HSV infections typically severe
No; usually mild or asymptomatic
72
When does widespread organ involvement occur in HSV infection
In immunocompromised hosts unable to limit viral replication; viremia ensues
73
What is the anatomical site primarily affected by HSV-1
Oropharynx
74
How is HSV-1 transmitted
Respiratory droplets or direct contact with infected saliva
75
What is the route of transmission for HSV-2
Genital routes
76
How long does viral persistence last in latently infected ganglia
For the lifetime of the host
77
How many viral genes are expressed during latent HSV infection
Very few
78
Do HSV reactivations occur despite host immunity
Yes; spontaneous reactivations occur despite HSV-specific humoral and cellular immunity
79
How do recurrent HSV infections compare to primary infections
Less extensive and less severe
80
What are the types of recurrent HSV infections
Asymptomatic (only viral shedding) or symptomatic (cold sores/fever blisters)
81
What is the virion shape of herpesviruses
Icosahedral
82
What type of genome do herpesviruses have
Double-stranded DNA; linear; large (>150kb)
83
How many polypeptides do herpesviruses encode
At least 70
84
What is the function of glycoprotein C in HSV
Complement (C3b) binding protein
85
What is the function of glycoprotein E in HSV
Fc receptor binding to Fc portion of IgG
86
What is the function of glycoprotein D in HSV
Induces neutralizing antibodies
87
What is the function of glycoprotein G in HSV
Type-specific glycoprotein allowing antigenic discrimination between HSV-1 (gG-1) and HSV-2 (gG-2)
88
How long does HSV replication require for completion
8-16 hours
89
Is intact skin susceptible to HSV infection
No; intact skin is resistant to HSV
90
Where do localized HSV lesions occur on the skin
In abrasions that become contaminated with the virus (traumatic herpes)
91
What is herpetic whitlow
HSV infection of fingers; common in dentists and hospital personnel
92
What is herpes gladiatorum
HSV infection of wrestlers' bodies (also called mat herpes)
93
What is eczema herpeticum
A primary HSV infection in a person with chronic eczema
94
What type of HSV causes sporadic fatal encephalitis in the US
HSV-1
95
What percentage of HSV encephalitis patients have primary infections
About half; the rest have recurrent infection
96
What is the most common source of neonatal herpes infection
The mother
97
What is the most common route of HSV transmission to newborns
Contact with herpetic lesions in the birth canal
98
What delivery method is recommended for mothers with active genital herpes
Cesarean section
99
What are the three categories of neonatal herpes disease
Lesions localized to skin/eye/mouth; encephalitis with or without skin involvement; disseminated disease involving multiple organs
100
What causes death in babies with disseminated herpes disease
Viral pneumonitis or intravascular coagulopathy
101
Which transplant recipients are at particular risk for severe herpes infections
Renal; cardiac; bone marrow transplant recipients
102
Which patients experience more frequent and severe HSV infections
Patients with hematologic malignancies; patients with AIDS
103
Which group is prone to fatal disseminated HSV infections
Malnourished children
104
What is the relationship between human herpes viruses and animal reservoirs
Human herpes viruses are not associated with animal reservoir or vectors
105
What can serve as a reservoir for HSV transmission
Asymptomatic or symptomatic infections
106
What is the mode of transmission for HSV-1
Contact with secretions (saliva) or fomites (usually utensils) contaminated with saliva of a virus-shedding person
107
Who typically infects children with HSV-1
Symptomatic adults with herpetic lesions or asymptomatic adults shedding virus
108
What percentage of adults can shed HSV-1
1% of adults
109
What happens in asymptomatic HSV-1 infection
Leads to carrier state for a lifetime with antibody development but virus is not eliminated
110
What percentage of adults have HSV-1 antibodies
70-90%
111
What percentage of US population is infected with HSV-2
40-60%
112
What is the mode of transmission for HSV-2
Sexually transmitted
113
When do HSV-2 antibodies typically appear
After puberty
114
What is the nature of antibody cross-reactivity between HSV types
Cross-reactivity exists between Type 1 and 2 antibodies; type-specific glycoprotein antigens are used for differentiation
115
What percentage of adults ages 30-49 have HSV-2 antibodies
0.17
116
Which demographic groups have higher HSV-2 infection rates
Women; blacks
117
What risk does maternal HSV pose
Can endanger mother and fetus (rare: disseminated infection after primary infection in mother)
118
How does a fetus acquire HSV
By birth canal shedding during delivery
119
What effect can primary HSV-1 have before 20 weeks gestation
Spontaneous abortion
120
How does genital HSV affect HIV acquisition
Increases chances of acquiring HIV due to ulcerative lesions or openings in mucosa
121
What antibodies do newborns have against HSV
Passively transferred maternal antibodies
122
When is the period of greatest susceptibility to HSV infection
Between ages 6 months and 2 years
123
When do HSV-1 antibodies begin to appear
In early childhood
124
When do HSV-2 antibodies begin to appear
During adolescence and with sexual activity
125
What is the antibody response pattern during primary HSV infection
IgM appears transiently followed by IgG and IgA which persist for long periods
126
What is the relationship between primary infection severity and immune response
The more severe the primary infection
127
What cytological finding is characteristic of HSV infections
Presence of multinucleated giant cells
128
What is the definitive diagnostic approach for HSV
Virus isolation
129
What laboratory technique is used for viral isolation of HSV
Inoculation of tissue cultures
130
How is the HSV agent identified after isolation
By neutralization test or immunofluorescence staining with specific antiserum
131
How is typing of HSV isolates performed
Using monoclonal antibody or by restriction endonuclease analysis of viral DNA
132
What has replaced viral isolation for diagnosis of HSV infections of the CNS
PCR amplification from CSF
133
When do antibodies appear after HSV infection
In 4-7 days after infection; reaching peak in 2-4 weeks
134
What virus causes chickenpox,
Varicella-zoster virus (VZV)
135
What is the incubation period for chickenpox,
10–21 days
136
What are early symptoms of chickenpox, Malaise
fever
137
Describe the progression of the chickenpox rash, Macules → papules → vesicles → crusts
all stages may appear simultaneously
138
Where does the chickenpox rash typically start, Face
chest
139
What are rare complications of chickenpox in healthy children, Encephalitis
pneumonia
140
Which groups are at high risk for severe chickenpox, Immunocompromised individuals
pregnant women
141
How is chickenpox transmitted, Respiratory droplets
direct contact with fluid from vesicles
142
What vaccine prevents chickenpox,
Live attenuated varicella vaccine
143
What causes shingles,
Reactivation of latent varicella-zoster virus (VZV)
144
What are early symptoms of shingles, Pain
itching
145
Describe the shingles rash, Unilateral stripe of vesicles
does not cross the midline
146
What is the most common complication of shingles,
Postherpetic neuralgia (PHN) – pain lasting >90 days after rash
147
Which demographic has the highest risk of PHN, Adults >50 years
risk increases with age
148
What serious complication occurs if shingles affects the eye,
Vision loss (herpes zoster ophthalmicus)
149
How does shingles affect immunocompromised patients,
Larger rash disseminated disease
150
What vaccine reduces shingles risk,
Recombinant zoster vaccine (RZV)
151
What antiviral is used to treat shingles,
Acyclovir valacyclovir
152
What percentage of shingles patients develop PHN,
10–18%
153
How does chickenpox differ from shingles in presentation,
Chickenpox: widespread rash Shingles: localized dermatomal rash
154
What distinguishes PHN from acute shingles pain,
PHN persists >90 days after rash resolution acute pain resolves with healing
155
Why is shingles not transmitted directly as shingles,
Reactivated VZV causes shingles transmission occurs as chickenpox in susceptible contacts
156
What innate immune cells respond to primary VZV infection
NK cells and interferon-alpha
157
What type of immunity prevents varicella reinfection
Lifelong immunity via memory B and T cells after recovery
158
How long does varicella vaccine immunity last
At least 20 years
159
What immune components control VZV reactivation
VZV-specific T cells (particularly CD4 and CD8)
160
Do antibodies prevent VZV reactivation
No; neutralizing antibodies exist but T cells are critical for latency control
161
What diagnostic method detects multinucleated giant cells
Tzanck smear of skin scrapings
162
Why is VZV culture rarely used
Low sensitivity; vesicle fluid is labile
163
Is VZV DNA detectable in CSF during early encephalitis
No; often undetectable at presentation
164
What is the reservoir for VZV
Humans only
165
How is VZV transmitted
Direct contact with vesicles or inhalation of aerosols
166
What season shows peak varicella transmission
Winter and early spring
167
What antivirals treat VZV infections
Acyclovir; valacyclovir; famciclovir; foscamet
168
What vaccine prevents varicella
Live attenuated vaccine (80-85% effective in children)
169
What vaccine reduces shingles risk
Zoster vaccine (Zostavax; 14x more potent than varicella vaccine)
170
Who should receive zoster vaccine
Adults >60 years or those with chronic conditions
171
What is unique about CMV's genetic content
Largest genome among human herpesviruses (240 kbp)
172
What cell type does CMV infect in vitro
Human fibroblasts
173
What cytopathic effects are characteristic of CMV
Perinuclear cytoplasmic inclusions + intranuclear inclusions; multinucleated cells
174
What is CMV's incubation period in normal hosts
4-8 weeks
175
How does CMV evade antibodies
Expresses Fc receptor to bind IgG nonspecifically
176
What maintains CMV latency in immunocompetent hosts
Host immune responses (especially T cells)
177
What is the most common CMV complication in transplants
Pneumonia
178
How does congenital CMV cause birth defects
Transplacental transmission during primary/reactivated maternal infection
179
What immune deficiency increases CMV reactivation risk
T-cell deficiencies (organ transplants; AIDS)
180
How long can CMV shedding occur post-infection
Months to years in pharynx/urine
181
What characterizes CMV infection in immunocompetent hosts
Asymptomatic in most cases; occasionally causes heterophil-negative mononucleosis syndrome (20-50% of non-EBV cases)
182
What complications occur in normal hosts with CMV
Rare; may include mild hepatitis or prolonged fever
183
What age group shows hepatosplenomegaly in CMV infection
Children <7 years old
184
What is the most common CMV complication in transplant recipients
Pneumonia (especially in lung transplants)
185
What hematologic effect occurs in organ transplant patients
Virus-associated leukopenia
186
What complication occurs in lung transplant recipients
Obliterative bronchiolitis
187
What vascular complication affects heart transplant recipients
Graft atherosclerosis
188
What rejection risk exists in renal transplants
CMV-related allograft rejection
189
What occurs in untreated AIDS patients with CMV
Disseminated disease (retinitis; colitis; encephalitis)
190
What fetal outcomes occur in congenital CMV
Intrauterine death; CNS/RES involvement; IUGR; jaundice; thrombocytopenia; microcephaly
191
What is the mortality rate for symptomatic congenital CMV
0.2
192
How does maternal CMV reactivation affect infants
Asymptomatic viral shedding in cervix during pregnancy; infants shed virus at 8-12 weeks
193
What is the CMV seroprevalence in adults >60 years
>80%
194
Does humoral immunity prevent CMV reactivation
No; reactivation occurs despite antibodies
195
Does breast milk antibody prevent CMV transmission
No; infants still acquire infection
196
How is active CMV infection detected
Quantitative PCR for viral load in blood/urine
197
What cell type is required for CMV isolation
Human fibroblasts (takes 2-3 weeks)
198
What sample types are used for CMV culture
Throat washings; urine
199
What indicates past CMV infection
Positive CMV IgG
200
What suggests recent CMV infection
Positive CMV IgM
201
What socioeconomic factor affects CMV prevalence
Living conditions and hygiene practices
202
How is CMV primarily transmitted
Close contact via saliva/respiratory secretions; blood transfusion (1-5% risk per unit)
203
What treatment is used for CMV retinitis
Foscarnet (first-line)
204
What drug controls congenital CMV hearing loss
Ganciclovir
205
What preventive measure reduces CMV in transplants
Donor/recipient antibody screening
206
What is the EBV genome structure
Linear double-stranded DNA (~172 kb) encoding ~85–100 genes
207
What are EBV's structural components
DNA core; icosahedral capsid (162 capsomers); tegument; lipid envelope with glycoproteins
208
What are the two major EBV strains
Type A (EBNA-2 variant) and Type B (differ in EBNA-2/EBNA-3 genes)
209
What cells does EBV primarily infect
B lymphocytes (via CD21 receptor) and epithelial cells
210
How is EBV transmitted
Through saliva ("kissing disease") and close contact
211
What occurs during primary EBV infection
Oropharyngeal infection → B cell immortalization → lifelong latency in memory B cells
212
What triggers EBV reactivation
Immunosuppression (transplants
213
What is infectious mononucleosis
Self-limited illness with fever
214
Which cancers are EBV-associated
Burkitt lymphoma; nasopharyngeal carcinoma; Hodgkin lymphoma; gastric carcinoma; post-transplant lymphomas
215
What is unique about Burkitt lymphoma
Jaw tumors in African children; malaria cofactor increases risk
216
Why is nasopharyngeal carcinoma prevalent in Chinese males
Genetic susceptibility (HLA variants) + environmental factors
217
What immune responses occur in EBV
Antibodies (VCA
218
How is EBV diagnosed
Serology (anti-VCA IgM for acute infection); PCR for viral DNA; EBER RNA in situ hybridization
219
Can EBV be cultured
Yes – immortalizes umbilical cord B cells (gold standard but rarely used)
220
What is EBV's global seroprevalence
>90% of adults worldwide
221
When do infections typically occur
Developing countries: age <6; industrialized nations: adolescence/young adulthood
222
What is the US mononucleosis burden
~100
223
Is there an EBV vaccine
No approved vaccine (experimental candidates in trials)
224
Does acyclovir cure EBV
Reduces viral shedding but doesn't eliminate latent infection or treat lymphomas
225
What shows promise for post-transplant EBV
Adoptive T-cell therapy targeting EBV antigens
226
EBV Type A vs Type B
Type A has stronger B cell transformation ability
227
EBV in immunocompetent vs immunosuppressed
Asymptomatic latency vs lymphoproliferative disorders/cancers
228
EBV-associated vs non-EBV lymphomas
EBV+ tumors express LMP1/EBNA2 (except Burkitt's EBNA1-only)
229
What is the structure of HHV-6
Enveloped herpesvirus with icosahedral capsid (~200 nm)
230
What is unique about HHV-6's genome
Contains telomeric repeats (GGGTTA) enabling chromosomal integration into human subtelomeres
231
How does HHV-6 achieve latency
Integrates viral DNA into host chromosomes (chromosomally integrated HHV-6/ciHHV-6)
232
What is HHV-6's primary clinical manifestation
Roseola infantum (exanthem subitum): high fever (3-5 days) followed by truncal rash
233
What neurological complications occur
Febrile seizures in children; encephalitis in immunocompromised patients
234
How is HHV-6 transmitted
Saliva/respiratory droplets; vertical transmission (rare)
235
What distinguishes HHV-6A and HHV-6B
6B causes childhood roseola; 6A more neurotrophic (linked to multiple sclerosis)
236
What is ciHHV-6
Inherited integrated HHV-6 in germline DNA (1% population)
237
How is HHV-6 diagnosed
PCR for viral DNA in blood/CSF; serology (IgM for acute infection)
238
What treatment is used
Ganciclovir/foscarnet for severe cases; no vaccine
239
What cells does HHV-7 infect
CD4+ T cells (uses CD4 receptor) and salivary gland cells
240
How does HHV-7 transmission occur
Saliva (75% adults shed virus)
241
What disease is linked to HHV-7
Roseola-like illness (less common than HHV-6)
242
When do most HHV-7 infections occur
Childhood (90% seropositive by age 6)
243
What diseases does HHV-8 cause
Kaposi sarcoma (vascular tumors); multicentric Castleman disease
244
How is HHV-8 transmitted
Sexual contact (MSM high-risk); saliva; organ transplants
245
What genes make HHV-8 unique
Pirated cellular genes (v-cyclin
246
How is HHV-8 diagnosed
PCR for viral DNA in blood/tissue; serology (latent nuclear antigen)
247
What animals carry B virus
Macaques (rhesus/cynomolgus) - enzootic in Asian Old World monkeys
248
How do humans acquire B virus
Monkey bites/scratches; ocular/respiratory exposure
249
What is B virus's main complication
Severe encephalomyelitis (70% mortality without treatment)
250
What post-exposure treatment is used
Acyclovir/valacyclovir immediately after exposure
251
How to prevent B virus
Strict PPE with macaques; avoid handling as pets
252
What fever pattern occurs in HHV-6 roseola
High fever (40°C+) for 3-5 days resolving before rash
253
Why is HHV-6 a key febrile seizure cause
Common in children 6-24 months; 20-30% of first febrile seizures
254
What distinguishes HHV-6 fever from bacterial causes
Abrupt defervescence coinciding with rash onset
