Virology Flashcards
1
Q
Intrauterine vs perinatal infection
A
before birth vs in 1w after birth
2
Q
5 significant intrauterine infections
A
Rubella
CMV
VZV
Parvovirus B19
Zika
3
Q
3 important perinatal infections
A
HSV1/2
Enterovirus
HPV
4
Q
How many adults are immune to rubella?
A
90%
5
Q
Transmission of rubella
A
Aerosol
6
Q
Presentations of rubella (3)
A
morbilliform rash (face to trunk to limbs)
fever, malaise
small joint pain
7
Q
Congenital infection of rubella and sequels on the foetus
A
<12w: congenital rubella syndrome (90%)
cataract, glaucoma, deafness, retardation, PDA, DM
12~16w: deafness (20%)
8
Q
Diagnosis of rubella
A
- Serology (IgM, serum acute + convalescent)
- PCR on urine / NPA / amniotic fluid
9
Q
Management for congenital rubella syndrome
A
<16w: counselling for termination of pregnancy
isolation
10
Q
Vertical transmission rate of CMV
A
40% for primary infection
1-3% for activation / reinfection
11
Q
Congenital infection of CMV (2)
A
Congenital cytomegalic disease (10-15%)
deafness (10%)
12
Q
Diagnosis of CMV congenital infection
A
[before birth] amniotic fluid PCR
[after birth] urine / saliva PCR
13
Q
Why CMV serology is not applicable in screening and diagnosis of congenital infection? (3)
A
- CMV IgG +ve in most adults –> screening not effective
- immaturity of baby to produce IgM
- could be FP by passively acquiring IgG from mother
14
Q
What’s the difference between congenital and post-natal infection of CMV? How to determine which is which?
A
- post-natal infection will not cause cytomegalic disease
- if sample +ve within 3 weeks, it must be congenital. Otherwise it is hard to determine
15
Q
% of adults with VZV IgG +ve
A
90%
16
Q
Congenital infection of VZV: timeframe
A
<20w: congenital varicella syndrome (1~2%)
>20w: zoster
perinatal (5d pre and 2d post): severe congenital varicella syndrome (fatal)
17
Q
Diagnosis of VZV congenital infection
A
clinical (seldom do vesicular swab)
18
Q
Management for risk of VZV congenital infection
A
Post-exposure prophylaxis by VZIG if the mother is susceptible
19
Q
% of adults having Parvovirus B19 IgG
A
30%
20
Q
Transmission of parvovirus B19
A
aerosol, blood products
21
Q
Presentations of parvovirus B19 infection
A
- 50% asymptomatic
- 5th disease / erythema infectiosum (“slapped face” rash)
- arthritis
22
Q
Congenital infection of parvovirus B19
A
all or none
anaemia, hydrops fetalis (25~33%)
23
Q
Transmission of Zika
A
vector borne, sexual, blood transfusion
intra-uterine, breast milk
24
Q
Diagnosis of Zika congenital infection
A
[Before birth]
1. Serology: IgM (acute + convalescent)
2. PCR on urine & blood
(timing: within 14 days from onset / back from endemic areas)
3. PCR on aminotic fluid / cord blood
[After birth]
- <7d: PCR on CSF
- >7d: IgM
25
Antenatal screening in HK (3)
Rubella IgG
HBsAg
HIV antibodies
26
What if antenatal screening reveals HBsAg positive on a pregnant lady?
- give antiviral (tenofovir) for mother at ~32w
- give hyperimmune globulin + vaccine for newborn
27
Which congenital infection can result in microcephaly? (2)
VZV, Zika
28
Vector for Zika virus
Aedes mosquitoes
29
Respiratory viruses that are more common in children (2)
RSV, Parainfluenza
30
Respiratory viruses (7)
Influenza, Adenovirus, RSV, Parainfluenza
Rhinovirus, Enterovirus, Coronavirus
31
Basic virology for influenza virus (family, genome, replication, envelop?)
Family: Orthomyxoviridae
Genome: (-) ssRNA, 8 segments
Replication: in nucleus
Enveloped with antigens
32
Types of antigens of Influenza virus (number of subtypes)
Haemaglutinin (18), Neuraminidase (11)
33
Groups of influenza virus
A~D (MC is A, only A, B, C infect human)
34
Diagnosis for influenza virus (2)
NPA for RT-PCR
Rapid antigen test by direct IF assay
35
3 classes of antivirals against influenza virus, examples of drugs (2+2+1), actions
M2 ion channel blocker:
- Amantadine, Rimantadine
- inhibit viral uncoating
Neuraminidase inhibitor:
- Zanamivir, Oseltamivir
- inhibit release
Cap depenpent endonuclease inhibitor:
- Baloxavir
- inhibit RNA transcription
36
Which class of antiviral against influenza is for group A only
M2 ion channel blocker
37
Vaccine types for influenza (2)
1. Inactivated vaccine (injected)
2. Live attenuated vaccine (intranasal)
38
Which pathogen causes formation of multinulceated giant cells?
RSV
39
Family and groups of RSV
Pneumoviridae
A, B
40
MC pneumonia in children
RSV
41
Treatment / Prophylaxis for RSV
Palivizumab 帕利非
42
Serotypes of parainfluenza virus
1,2,3,4a,4b
43
Subgenera of adenovirus
A~G
44
Family, genome, and groups of Rotavirus
Reoviridae, dsRNA, A~E
45
MC viral GE inchildren
Rotavirus
46
Diagnosis of rotavirus
Stool or rectal swab
antigen detection by enzyme immunoassay or latex agglutination
(microscopy)
47
Vaccines for rotavirus (2) (nature) (time) (complication)
RotaRix, RotaTeq
[oral] live attenuated vaccine
1st dose 6-15w, 2nd dose before 32w
intussuception
48
Which 2 serotypes of adenovirus can cause enteric infection?
40, 41
49
2nd MC viral GE in children
adenovirus
50
MC viral GE in adults
Norovirus
51
Pathogen for winter vomiting disease
Norovirus
52
Pathogen for projectile vomiting
Norovirus
53
Diarrhoeal viruses (5)
1. Rotavirus
2. Adenovirus
3. Astrovirus
4. Norovirus
5. Norwalk virus
54
Family and genome for each hepatic virus (which 2 viruses are enveloped?)
HAV: picornaviridae, (+) ssRNA
HBV: hepadnaviridae, dsDNA
HCV: flaviviridae, (+) ssRNA
HDV: /
HEV: hepeviridae, (+) ssRNA
(HBV, HCV)
55
Which hepatic viruses
(a) have HCC risk?
(b) have vaccine available?
(a) HBV, HCV
(b) HAV, HBV
56
Diagnosis of infection of each hepatic virus
HAV: HAV IgM
HBV: HBsAg, HBV DNA
HCV: HCV combo assay (IgG + core Ag), RNA
HEV: HEV IgM, PCR
57
Vaccine type for HAV
inactivated vaccine (monovalent or bivalent)
58
How many genotypes of HEV are there? Which is prevalent in East Asia / HK?
5, 4
59
Which pathogen shows Dane particle under microscope?
HBV
60
HBV chronic infection diagnosis
HBsAg +ve >6 months
61
Implication of anti-HBs, anti-HBc IgM IgG, HBeAg, anti-HBe
anti-HBs ==> immunity
anti-HBc IgM ==> recent infection
anti-HBc IgG ==> previous infection
HBeAg ==> high infectivity
anti-HBe ==> low infectivity
62
When does universal immunization for HBV start?
1988
63
Vaccine type for HBV
recombinant subunit vaccine
64
Treatment for HBV
Interferons
Antivirals (Entecavir, Tenofovir)
65
Which antiviral is preferred for HBV in pregnancy?
Tenofovir
66
Treatment for HCV
Peg-interferon, Ribavirin
67
Family, genus, genome, types of HIV
Retroviridae, Lentivirus, ssRNA-RT, 1&2
68
Which type of HIV is found mainly in Africa?
HIV2
69
Clinical course of HIV
1. Seroconversion illness (IM-like symptoms)
2. Latent phase
3. Acquired immunodeficiency syndrome
70
Diagnostic algorithm for HIV and diagnosis of AIDS
Diagnostic algorithm:
1. 4th generation HIV1/2 immunoassay
(if positive --> step 2)
2. HIV1/2 Ab differentiation immunoassay
(if negative --> step 3)
3. HIV RNA PCR
AIDS:
1. Lab confirmed HIV
2. CD4+ T cell count <200 cells/mm^3 or <14%, or AIDS defining conditions
71
Treatment for HIV
HAART (highly active anti-retroviral therapy)
1. Dual NRTI (nucleoside/-tide reverse transcriptase inhibitor)
2. Adjuvant (1 out of 3)
a. NNRTI
b. protease inhibitor
c. integrase strand-transfer inhibitor
72
Which virus family look like sunny egg under EM?
Herpesviridae
73
Which herpes viruses do not have a high prevalence?
HSV2, HHV-8
74
Which herpes viruses are not dermatotropic?
EBV, CMV
75
Which herpes viruses are not neurolatent?
EBV, CMV, HHV8
76
Which herpes viruses are not lympholatent?
HSV1, HSV2, VZV
77
Transmission of HSV1 and HSV2
HSV1: kissing
HSV2: sexual transmission
also perinatal
78
Latency region for HSV1,2
local sensory DRG (e.g. trigeminal, sacral ganglion)
79
Diagnosis of HSV1,2
1. [CSF] PCR
2. [Skin scrape] IF
3. [Vesicular fluid] PCR, viral culture
80
Treatment for HSV1,2
Acyclovir
81
What are the only 2 airborne viruses?
Measles, VZV
82
Treatment for post-herpetic neuralgia
Amitriptyline
83
Pathogen for Ramsay-Hunt syndrome (What is it?)
VZV
(facial nerve palsy due to involvement of CN7 genicular ganglion)
84
Latency region of VZV
DRG
85
Vaccine type for VZV
Chickenpox: live attenuated vaccine
Zoster: live attenuated / recombinant subunit vaccine
86
Vaccination of VZV for healthcare workers
routine VZV IgG check --> if titre declined: 2 doses of chickenpox vaccine
87
Diagnosis of VZV
mainly clinical
88
Transmission of EBV (full name?)
kissing (saliva), sexual
(Epstein-Barr virus)
89
Latency site of EBV and consequences from reactivation
oropharynx, B cells
nasopharyngeal CA, Burkitt lymphoma
90
Early screening for nasopharyngeal CA
EBV IgA, EBV DNA
if positive: endoscopy / biopsy
91
Latency site and transmission of CMV
salivary glands, kidneys, haemopoietic progenitors
saliva, urine, blood transfusion / transplant / intrauterine
92
Diagnosis of CMV (3)
[urine/ saliva] PCR, viral culture
[amniotic fluid] PCR, viral culture
histology from pathological tissue
93
Pathogens for owl eye appearance of cells under histology
CMV
94
Treatment for CMV
Ganciclovir
95
Which herpes virus can be found in urine?
CMV
96
Presentations of HHV6 (primary and reactivation)
Latency site (2) and transmission
Primary infection: Roseola infantum
Reactivation: encephalitis
Latency: T lymphocytes, brain
Transmission: Kissing
97
Tumour related to HHV-8
Kaposi's sarcoma (AIDS defining)
98
Pathogens transmitted by Aedes mosquitoes (4)
Dengue, Zike, Yellow fever, alpha viruses
99
Pathogens transmitted by Culex mosquitoes (2)
JEV, West Nile fever virus
100
Pathogens transmitted by Ticks (3+2)
Rickettsia rickettsii, Coxiella burnetii, Borrelia burgdorferi
Tick-borne encephalitis, St Louis encephalitis
101
Pathogens transmitted by mites (2)
Orientia tsutsugamushi
Rift valley fever / sandfly fever virus
102
MC arbovirus family (genome)
Flaviviridae
(+) ssRNA, enveloped
103
CBC findings in most arbovirus infection
↓ WCC, ↓ Plt
104
Arboviruses that cause pan-encephalitis (3)
JEV, tick-borne encephlitis virus, St Louis encephalitis virus
105
Arbovirus that causes hepatitis
Yellow fever virus
106
Supportive management for arbovirus infection
Ribavirin
107
Which 4 arboviruses does HK give vaccination against?
Dengue virus, JEV, yellow fever virus, tick-borne encephalitis virus
108
Vector control methods for mosquitoes (3)
ovitrap (for vector surveillance)
water hygiene
solid waste management
109
How many serotypes of Dengue virus are there?
4
110
MC vector for Dengue virus in HK (What type of host is human in the context of Dengue virus?)
Aedes albopictus 白紋伊蚊
amplifying host
111
MC vector for JEV in HK (What type of host is human in the cost of JEV?)
Culex tritaeniorhynchus
accidental host
112
Molecular mechanisms of viruses to cause cancers in humans
(a) ssRNA
(b) Herpesviridae
(c) other dsDNA / ssRNA-RT
(a) chronic inflammation
(b) as episomal gene to produce oncogene
(c) integrate into human genome to express viral oncogene
113
Which pathogen appears as golf ball under EM?
Papovaviridae / HPV
114
Which serotypes of HPV cause warts?
6,11
115
Which serotypes of HPV have high risk to develop into CA cervix?
16,18
116
Carcinogenesis of HPV
viral integration --> ↑ E6, E7 --> ↓ p53, pRb
117
3 vaccines for HPV
bivalent (16,18), quadrivalent (16,18,6,11), nonavalent
118
Screening for HPV (2)
Pap smear for cytology
HPV test
119
Investigations for measles virus
Serology for measles IgM
NPA: PCR for viral detection
120
Antigenic drift vs shift
Drift: replication error of RNA polymerase, Flu A & B, epidemic
Shift: genetic reassortment btw 2 strains, Flu A, pandemic
