Day 7.2 and 7.3 Micro- Virology Flashcards Preview

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Flashcards in Day 7.2 and 7.3 Micro- Virology Deck (142):
0

Use for acyclovir, ganciclovir

Acyclovir = HSV, VZV, EBV
Ganciclovir = CMV
If these fail, can use foscarnet.

2

HBsAg

Surface Ag
Have disease right now

3

HBsAb

Surface Ab
Either recovered from dz
OR have been immunized

4

HBcAg

Core Ag
Indicates new dz, but this is not something that can be measured in the serum, so won't get a measurement for it on the test.

5

HBcAb

Core Ab
Hx of active dz (only- will NOT be positive if you have just been immunized)

6

What are the core HBV Ab?

IgM for early, active dz
IgG later, for chronic dz

7

HBeAg

E Ag
Indicates active infection
and HIGH lvl of transmissibility
High E = High Enfectivity
eg Chronic contagious

8

HBeAb

E Ab
Indicates infection but chonic, LOW transmissibility
eg Chronic low-infective

9

What will the HBV serologic markers show in active dz?

HBsAg +
HBsAb -

HBeAg +
HBeAb -

HBcAb + (IgM)

10

What will the HBV serologic markers show in the window period (equivalence zone)?

HBsAg -
HBsAb -

HBeAg -
HBeAb -

HBcAb + (IgM)

There are Ab present, but they're all bound to Ag, so nothing is detected in the assay. Confusing, but you know it bc of the IgM core Ab, which indicate a newer infection.

11

What will the HBV serologic markers show in a chronic, highly infective state?

HBsAg +
HBsAb -

HBeAg +
HBeAb -

HBcAb + (IgG)

Think: dz is winning!
This is the same as active dz except for the core Ab is now IgG since it's chronic.

12

What will the HBV serologic markers show in a chronic, low-infective state?

HBsAg +
HBsAb -

HBeAg -
HBeAb +

HBcAb + (IgG)

Will still have +surface Ag and -surf Ab bc you still have dz.
But, since it's low infective (and E is for Enfectivity, your E Ag will be neg (and E Ab pos)

13

What will the HBV serologic markers show in complete recovery?

HBsAg -
HBsAb +

HBeAg -
HBeAb +

HBcAb + (IgG)

Winning! All Ag's neg, all Ab's positive

14

What will the HBV serologic markers show in an immunized pt who has never had dz?

HBsAg -
HBsAb +

HBeAg -
HBeAb -

HBcAb - (this is the only time core will be negative, if you have Ab. other scenario is never had it and never vaccinated)

15

Which Hepatitis virus is a DNA virus?

HBV

16

Transmission of chicken pox vs shingles

Chicken pox = respiratory
Shingles = only by direct contact w active lesions. Cover them and they won't be spread.

17

Where does HSV1 lie dormant?

Trigeminal ganglion

18

Where does HSV2 lie dormant?

S2 and S3 ganglia

19

Where does VZV (chicken pox and shingles) lie dormant?

Trigeminal ganglia and dorsal root ganglia

20

What does EBV cause?

Infectious mono
Burkitt's lymphoma (endemic)
Hodgkin's lymphoma
nasopharyngeal carcinoma
thymic carcinoma
oral hairy leukoplakia

21

What can EBV look similar to? If pt is treated for wrong thing, what happens?

Looks like strep throat
If pt is given aminopenicillins (amoxicillin) for the strep, they will get a rash (and will think they are allergic to amox)
EBV + amox = rash

22

If the pt has mono but has a negative monospot, what is the cause?

Probably CMV

23

When CMV affects AIDS pts, what are they prone to?

Pneumonia from CMV
Esophagitis from CMV

24

What age does roseola usu infect?

7-13 months
Roseola = HHV-6

25

What cancer can be caused by HBV and HCV?
Tumor marker for it?

Hepatocellular carcinoma
Alpha feroprotein (AFP)

26

Main txmsn of HBV

Sexual
Also parenteral (eg injection) and maternal-fetal

27

Main txmsn of HCV

Parenteral (IV drug users)
Also post-transfusion if blood not screened.

28

Rx for HCV

Alpha-interferon (Interferon-alpha)
Ribavirin

29

What causes aplastic crisis in sickle cell pts?

Parvo B19

30

Which papilloma viruses cause warts? CIN?

Warts = 1, 2, 6, 11
Cervical interepithelia neoplasia = 16, 18

31

What is the polyoma virus? What does it cause?

JC virus, causes PML in HIV pts
PML - progressive multifocal leukoencephalopathy

32

What is molluscum contagiousum?

Flesh-colored dome lesions w a central dimple (on skin)
It's a poxvirus

33

Only DNA virus that is not double stranded?

Parvo B19

34

Downey cells

EBV
Downey cells are the abn circulating Cytotoxic T cells (atypical lymphocytes). They have a foamy cytoplasm.

35

Main char- yellow fever

High Fever
Hemorrhagic Dz- Black vom!
Jaundice

Can cause liver, renal dz
Weird tongue: red on tip and sides but white in center

36

Child w major diarrhea in winter months

Rotavirus
ROTA = right out the ass

37

Influenza virus Ag

Hemagglutinin- promotes viral entry
Neuraminidase- promotes release of progeny viruses

38

Pts w influenza are at risk for bacterial superinfection from what?

S. pneumonia, H. influenza, etc
Anything that causes pneumonia
Can be fatal.

39

Shift vs drift

Shift = Reassortment. Worse. (Oh Shift!)

Drift = minor chg based on random mutation.

40

Things that cause aseptic (viral) meningitis

Cocksackie virus
Echovirus
(they are both enteroviruses)

41

What is another name for measles virus?

Rubeola
(RUBy has measles, and is ruby red from head to toe)

(RuBELLA is visiting from Germany for 3 days)
(ROSEola is HHV-6. I want 6 roses for my birthday.)

42

T/F immunodeficient pts who get measles won't have a rash or Koplik spots.

True.
The rash and spots are immune rxns, so pts w/o good immune systems won't get them.
The reactions take place in the endothelial cells of dermal capillaries.

43

In what direction on the body does the measles rash spread?

From head to toe (can of paint)

44

What congenital heart defects are caused by Rubella?

PDA and Pulmonary Artery Stenosis

ruBELLA is visiting from Germany for 3-days.

45

What RNA viruses cause aseptic meningitis and myocarditis?

Echovirus
Coxsackie virus

46

Which polio vaccine is live attenuated?

Sabin is live-attenuated and given orally.
SalK is Killed.

47

How does polio cause paralysis?

Affects the motor neurons of the anterior horn.

48

#1 cause of fatal diarrhea in kids

Rotavirus

49

What RNA virus is causes meningitis in summer months?

Echovirus, bc it is transmitted in swimming pools

50

Tourniquet test is for which RNA virus?

Dengue fever

51

West Nile Virus: reservoir, vectors, hosts

Reservoir- birds
Vectors- mosquitos
Incidental hosts (only bc mosquitos bite them): humans, horses, dogs

52

West Nile virus sympt

Most people: flu-like
1/150 have severe case: meningitis (possibly w encephalitis) incl muscle weakness and flaccid paralysis bc of anterior horn involvement.

53

Avian influenza

H5N1
Bird to human only
URI, diarrhea, fever, pancytopenia, elevated liver enz
Rx: oseltamavir (tamiflu)

54

H1N1 influenza

Swine flu
Flu + GI sympt
Rx oseltamavir or zanamivir but only in high risk or severly ill pts bc of wide spread resistance and side effects

55

Asthma sympt in a preemie in winter

RSV (bronchiolitis)

56

Rx for preemies in winter months

Passive immunization w Palivizumab (monoclonal RSV Ig) monthly during winter to protect them from RSV
Also give it to infants w chronic lung dz.

57

Low-pitched barking cough in kid <4yo

Croup (Parainfluenza virus)
Xray may show steeple sign

58

T/F Ribavirin is the Rx for RSV

True... but NOT in kids.
Used in adults if RSV develops after bone marrow txplt.

59

What anti-viral can be used for Parkinsons?

Amantidine (historically for influenza) has side effect of releasing dopamine from nerve terminals, so can be used.
Rimantidine does not cross the BBB so it cannot be used.

60

First line Rx for HSV or EBV

Acyclovir (or others- Famcyclovir)

61

Second-line for CMV retinitis

Foscarnet

62

Inhibits CMV DNA polymerase

Ganicyclovir
(Foscarnet too)

63

Inhibits viral DNA polymerase when phosphorylated by viral thymidine kinase

Acyclovir, Ganciclover, Famcyclovir, Valacyclovir

64

What kind of virus is HIV (DNA, RNA)

ssRNA
It has a diploid genome (2 RNA molecules)
However, despite being RNA it has to integrate into host DNA, so Reverse Transcriptase synthesized dsDNA from the RNA, and the dsDNA integrates into the host genome w the help of DNA integrase.

65

What receptors does HIV bind to on host cells?

Binds to CXCR4 and CD4 on Tcells (the "T-tropic strain does this, called X4 virus)
Binds to CCR5 and CD4 on macrophages (the macrophage-tropic strain does this- called R5 virus)

66

What HIV membrane protein protein binds to CXCR4, CCR5, and CD4 receptors on host cells?

gp120 envelope protein (the grabber)

67

What HIV membrane protein is responsible for fusion and entry of the virus?

gp41 envelope protein

68

What mutations are protective against HIV?

CCR5
homozygous for mutation = immune
heterozyg = slower course of dz

69

If the ELISA is negative, what do you do next?

Tell the pt they don't have HIV.
Negative ELISA means no HIV- ELISA is a rule out test.

70

If the ELISA is positive, what do you do next?

ELISA has a high false-pos rate, so do a Western Blot to confirm.

71

Normal CD4 count vs AIDS dx

Normal = 500-1500
AIDS = <200

72

How can you make the dx of AIDS?

<1.5

73

If an infant tests positive, how can you tell if they have HIV, or if their positive test is just bc of maternal Ab?

Check the infant's viral load.
Or, wait a few months and test again.

74

Prophylaxis for HIV+ at different CD4 levels

<50 continue TMP-SMX and azith; if pt has had prev hx of cryptococcal meningitis, then give fluconazole (but only w hx)

75

When should HAART be started?

Pt has AIDS-defining illness (PCP pneumonia)
Low CD4+ (<350)
High viral load

76

List protease inhibitors

NAVIR tease a protease.
Saquinavir
Ritonavir
Indinavir
Nelfinavir
Amprenavir
Lopinavir
Atazanavir

77

How do protease and protease inhibitors work?

Normally, HIV virion assembly depends on HIV-1 protease, which cleaves the polypeptide products of HIV mRNA into their functional parts.
Protease inhibitors prevent HIV virions from being able to process their own DNA (prevents maturation of virions in progeny)

78

Nephrolithiasis is a side effect of which HIV drug?

Indinavir (PI)

79

Pancreatitis is a side effect of which HIV drugs?

Pancreatitis alone - Ritonavir (PI)
Pancreatitis + periph neuropathy - didanosine, zalcitabine, stavudine (NRTIs)

80

Lipodystrophy and hyperglycemia are side effects of which drugs?

Saquinavir, Indinavir, Amprenavir (PIs)

81

What are the side effects of PIs that are class effects (all drugs in the PI class cause them)?

GI intolerance (v common)
Cytochrome P450 inhibition (this one is not nec bad- can extend heart meds)

82

How do NRTIs work?

Nucleoside Reverse Transcriptase Inhibitors
They competitively inhibit nucleotide binding to Reverse Transcriptase, and therefore terminate the DNA chain
They need to be phosphorylated (activated) by thymidine kinase in order to work.

83

List the NRTIs

Zidovudine (ZDV, used to be AZT)
Didanosine (ddI)
Zalcitabine (ddC)
Stavudine (d4T)
Lamivudine (3TC)
Abacavir

Have you dined (-vudine) with my nuclear family?

84

Which HIV drug causes Hepatic steatosis (fatty liver)?

Didanosine, Stavudine (NRTI)

85

Which HIV drug causes HPS rxns?

Abacavir

86

How do NNRTIs work?

Non-nucleoside Reverse Transcriptase inhibitors
Non-competitively (irreversibly) bind to inhibit RT.
Do NOT need to be phosphorylated to be active.

87

List the NNRTIs

Nevirapine
Efavirenz
Delavirdine

The non-nucleosides
Never Ever Deliver nucleosides.

88

Which class of HIV drugs causes rash?

NNRTIs

89

Which HIV drug causes a false-pos test to cannabinoids?

Efavirenz (NNRTIs)

90

Which NNRTI causes confusion as a side effect?

Efavirenz

91

Which HIV drug causes bone marrow suppression?

ZDV zidovudine (NRTI)
Bone marrow suppression - neutropenia, anemia
GM-CSF can be used to reduce the suppression.

92

What HIV drug is a fusion inhibitor? How does it work?

Enfuvirtide
Binds gp41, inhibiting the conformational chg req'd for its fusion w CD4 cells
Therefore, entry (and thus replication) is blocked

93

What drug is used during pregnancy to PMTCT?

Zidovudine
(now, HAART as well)

94

What drug is given for HIV+ needle stick pts?

Zidovudine with Lamivudine

95

Which HIV drug is an integrase inhibitor? How does it work?

Raltegravir
Integrase helps integrate viral DNA into host DNA- this blocks integrase.

96

What drug is a CCR5 antagonist? How does it work?

Maraviroc
Binds CCR5 on macrophgs, inhibiting the gp120 confirmational chg (so gp120 can't grab on to it)
Pt must first have a test to see if their HIV is the R5 type.

97

Which HIV drugs cause lactic acidosis?

NRTIs (but not abacavir)

98

Which HIV drug causes megaloblastic anemia?

Zidovudine

99

HAART

combo to control infection and avoid resistance
often 2 NRTIs + PI

100

Diarrhea caused by non-motile gram-neg org that does not ferment lactose

Shigella

101

Gram-neg motile org that doesn't ferment lactose and causes diarrhea

Salmonella (salmon swim- motile!)

102

Diarrhea from gram-neg lactose+ with no fever

E. coli

103

Food poisoning from undercooked hamburger

E. coli O157:H7

104

Food poisoning sympt after handling reptiles (turtles)

Salmonella

105

Pneumonia in immunocomp

Pneumocystis jiroveci

106

Most common cause of atypical pneumonia

Mycoplasma pneumonia

107

Pneumonia in alcoholic

Klebsiella

108

Pneumonia from air conditioners

Legionella pneumophilia

109

Most common pneumonia in kids <1yo

RSV

110

Most common cause of pneumonia in neonate (birth to 28 days)

GBS or Ecoli

111

Most common cause of pneumonia in kids and young adults (college students, military, prisoners)

Mycoplasma pneumonia

112

Cause of pneumonia in pts w other health issues

Klebsiella

113

Most common viral pneumonia

RSV

114

Woolsorter's dz (life threatening pneumonia)

Bacilis anthracis

115

Endogenous flora in 20% of adults that can cause pneumonia

S. pneumonia

116

Bacterial cause of COPD exacerbation

H. influzenza

117

Pneumonia in ventilator pts

Pseudomonas

118

Pneumonia in CF pts

Pseudomonas

119

Pontiac fever

Legionella pneumophilia

120

Rx for kids w meningits

Ceftriaxone (3rd gen)
+dexamethasone to reduce neurologic sequella

121

Rash seen in N. meningitidis

Purpura fulminans (big! and bad)

122

How to dx osteomyelitis

Radiographic bone scan or MRI

123

Male infant congenital defects which can lead to UTI

Posterior urethral valves (send urine back to bladder)
Hypospadius, epispadius

124

Elderly pt w delirium

UTI or anti-cholinergic drugs

125

CSF findings in bacterial meningitis

Increased prs
Increased PMNs
Increased protein
Decreased sugar

Same as fungal/TB meningitis, except for the cell type is different!

126

CSF findings in fungal/TB meningitis

Increased prs
Increased lymphocytes
Increased protein
Decreased sugar

Same as in bacterial meningitis except cell type is different (PMNs for bacterial)

127

CSF findings in viral meningitis

Normal or increased prs
Increased lymphocytes (will have lymphcytosis of the CSF)
Normal or increased protein
Normal sugar

With viral, everything can be normal in the CSF except for the lymphocytosis.

128

Organisms with urease

Particular Kinds Have Urease
Proteus
Klebsiella
H. pylori
Ureaplasma

129

What does urease do?
What organism makes urease and causes stones?

Breaks down urea into ammonium.
Proteus mirabilis makes urease: Ammonium can bind to magnesium and phosphate and make stones (staghorn struvite stones)

130

If leukocyte esterase urine test is positive, what does this indicate?

That there is inflammation.
May be bacterial, but not necessarily so.

131

If a nitrate urine test is positive, what does this indicate?

That a gram-neg organism is present.

132

RX for UTIs

TMP-SMX, fluroquinolones, nitrofurantoin
If prego: 1st/2nd gen cephalosporins, aminopenicillin, nitrofurantoin

133

What is the cause of unilateral hearing loss in a neonate?

CMV

134

What measures are used to prevent vertical txmsn of HIV?

Zidovudine, HAART
C-section

135

What is the cause of temporal lobe encephalitis in a neonate?

Herpes simplex virus

136

What does Parvo B19 cause in pregnancy?

Hydrops fetalis

137

Cause of bacterial vaginosis

Polymicrobial:
Gardnerella vaginalis
Mobiluncus
Anaerobes
Only an STD sometimes.
Clue cells have rough borders.

138

Risk factor for nosocomial Candida albicans?

Hyperalimentation (aka overeating/getting too many nutrients
often bc of total parenteral nutrition

139

Neonate has snuffles (blood-tinged nasal secretions)- what do they have?

Congenital syphilis

140

Neonate w rash followed by desquamation of hands/feet

Congenital syphilis

141

pH, findings, wet prep for:
physiologic vag discharge
candidiasis
trichomonas
bacterial vaginosis

physiologic: low pH (vag is acidic), usu px is young girl in puberty; wet prep- WBCs

Candida: low pH, cottage cheese, wet prep- budding yeast w pseudohyphae. Use KOH prep to see better.

Trich: high pH, irritation, itchy, strawberry cervix, see triangular organisms on wet prep

Bacterial vag: high pH, fishy smell, greenish. See clue cells on wet prep.

142

Know most common causes of pneumonia per age group
Know most common causes of meningitis per age group

p177-8