Virology Flashcards Preview

Step 1 AB > Virology > Flashcards

Flashcards in Virology Deck (159):
1

a. What are the Picornaviruses?
b. What kind of virus are they?

a. HAV, Enteroviruses (Polio, Coxsackie A/B, Echovirus) and Rhinovirus
b. ss naked + linear RNA virus

2

How are Picornaviruses spread?

Fecal oral (Except Rhinovirus)

3

a. What is the pathology of Poliovirus?
b. What is the clinical course of Poliovirus?

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

What are the two vaccines available for Poliovirus?

1. Salk - inactivated vaccine given parenterally (only forms IgG)
2. Sabin - live attenuated given orally (forms IgG AND IgA Abs)

5

What diseases do Coxsackie virus A cause?

1. Hand, foot, mouth disease (red vesicular rash)
2. Aseptic meningitis infection in summer

6

What diseases do Coxsackie virus B cause?

1. Dilated cardiomyopathy
2. Devil's grip, pleurodynia, Bornholm's disease

7

Which viruses are SS + linear?
a. naked
b. enveloped

a. picornaviruses (echo, coxsackie, polio, rhino, HAV), hepevirus, calicivirus
b. flavivirus, togaviruses, retroviruses, coronaviruses

8

Where do + RNA viruses replicate?

In the cytoplasm

9

What Calicivirus causes gastroenteritis?

Norovirus

10

Norovirus
a. Where are infections common?
b. Causes?

a. Outbreaks with lots of people in close quarters (cruises, young kids in daycare), consumption of shellfish/buffets
b. Causes explosive diarrheal illness

11

What are the Flavivirus viruses?

HCV
Yellow fever
Dengue fever - break bone fever, thrombocytopenia, renal failure
West Nile virus - encephalitis, flaccid paralysis, seizures, coma

12

a. What kind of virus is Togavirus?
b. What are examples of Togaviruses?

a. ss + RNA virus, enveloped
b. Rubella, Western/Eastern Equine Encephalitis

13

What is the clinical disease caused by Rubella

-Postauricular and occipital lymphadenopathy
-Arthralgia and arthritis (adults)
-Descending maculopapular rash that starts on face; 3 days (kids)
-Congenital Rubella

14

What are symptoms of congenital Rubella?

Sensorineural deafness
Congenital cataracts
PDA
(Jaundice, blueberry muffin rash)

15

a. What is Coronavirus?
b. What illnesses does it cause?

a. SS + RNA, enveloped (helical)
b. SARS, MERS, common cold

16

What are the 3 structural genes of HIV and what do they code for?

1. 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
2. gag (p24) - capsid protein
3. pol - reverse transcriptase, aspartate protease, integrase

17

a. What kind of virus is HIV?
b. How does it enter host?

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

How is diagnosis of HIV made?

Screening test - ELISA
Confirmatory test - Western blot

19

How is diagnosis of HIV made in babies? Why?

PCR; ELISA/Western blots are often falsely positive initially in babies born to infected mothers because gp120 can cross the placenta

20

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. Rickettsia rikettsii
b. Tick (Dermacenter - dogtick)
c. Francisella tularensis (lymphadenopathy, site specific ulcer, granuloma formation)

21

What vector transmits the following diseases and what do they cause?
a. Trypanosoma cruzi
b. Yersinia pestis
c. Plasmodium vivax
d. Leishmania donovani

a. Reduviid bug; Chagas disease
b. Flea; Plague
c. Mosquito; malaria
d. Sandfly; Visceral leishmaniasis

22

What species/diseases does the Ixodes tick transmit?

1. Anaplasma phagocytophilum - human granulocytic anaplasmosis
2. Borrelia burgdorferi - Lyme disease
3. Babesia microti -

23

Which stain do you use for each of the following?
a. Cryptococcus neoformans
b. Pneumocystis jirovecii
c. Chalmydia

a. India ink
b. Silver stain
c. Giemsa stain

24

What kind of virus is Orthomyxovirus?

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