STIs Flashcards

1
Q

Pregnancy treatment of C4

A

Amoxicillin, erithromycin, azithromycin

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2
Q

% of asymp CT

A

50% men and 70% women

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3
Q

What is CT bacteria

A

Obligate intracellular human parasite

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4
Q

Life cycle length of CT

A

48-72 hours

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5
Q

How does CT enter a cell

A

Endocytosis

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6
Q

CT life cycle

A
  1. Infectious elementary body attaches via endocytosis
  2. Differentiates into larger replicating bodies
  3. Inclusion membrane formed
  4. EBs form in inclusion membrane
  5. Cells lyase and release CT
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7
Q

Test of choice for CT

A

NAAT

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8
Q

What temp.for.NAAT storage

A

Room temp

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9
Q

CT NAAT turn around

A

2-3 days

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10
Q

Are NAATs approved for extra-genital sampling

A

No.
Does appear to work well for it however.

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11
Q

NAAT limitation

A
  1. DNA contamination
  2. Inhibition of assay
  3. Detection of non viable organism
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12
Q

Positive predictive value of CT Naat

A

> 95%

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13
Q

Where is new variant CT most common

A

Sweden

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14
Q

Most at risk group of LGV

A

MSM (and HIV)

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15
Q

CT TOC time?

A

5 weeks
(6 weeks if azithromycin)

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16
Q

Why must TV micro be done immediately

A

20% lose motility in 10 minutes

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17
Q

What TV test cannot be used for men

A

Direct antigen POC test

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18
Q

Most successful chance of TV culture

A

Direct innoculation to growth medium

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19
Q

Hallmark of trichomonads?

A

Characteristic tumbling motility

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20
Q

Best stain for TV?

A

Acridine orange

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21
Q

Sensitivity of wet microscopy for TV

A

45-60% in women
Lower in men

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22
Q

Highest sensitivity test for tv

A

NAAT (88-97%)

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23
Q

NAAT specifity for TV

A

98-99%

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24
Q

Male NAAT sensitivity TV

A

Urine 74%
Swab 95%

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25
Q

TV window period

A

10 days

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26
Q

Culture plate for thrush

A

Sabourauds medium

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27
Q

Direct microscopy signs of candida

A

Gram positive spores
Pseudohyphae

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28
Q

Steps to dry microcoscopy

A
  1. Fix with heat
  2. Stain with violet
  3. Aqueous iodine
  4. Decolourise with acetone
  5. Red counterstain
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29
Q

Sensitivity of thrush slide

A

Gram stain - 65%
Wet - 40-60%, specific

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30
Q

Accuracy of germ tube formation for candida albicans

A

> 95%

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31
Q

Rate of non-albicans in vvc cases

A

5-10%

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32
Q

Asymp Candida rates?

A

20% non pregnant
40% pregnant

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33
Q

Most common cause of recurrent thrush

A

Candida albicans

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34
Q

When is repeat testing for thrush indicated

A

After treatment of persistent non-albicans infection.
Cure is 2 neg cultures at least 7 days apart

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35
Q

How many of Amsels criteria to diagnose BV

A

3 of 4

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36
Q

Normal vaginal ph

A

4.5

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37
Q

Vaginal.ph in BV

A

Greater than 4.5

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38
Q

Factors that elevate vaginal PH

A

BV
TV
Sperm
Menses

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39
Q

What is used to perform.whiff test for BV

A

10% KOH

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40
Q

What is Zheil neelsen staining used for

A

TB and leprosy

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41
Q

What colour do gram stained bacteria go

A

Gram +ve purple
Gram -ve red/pink

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42
Q

What is the Ison-Hay grading for

A

Vaginal flora (grades 0-4)
Grade 3 is BV

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43
Q

What is Amsels criteria

A
  1. Thin homogeneous vaginal discharge
  2. Vaginal ph > 4.5
  3. Positive whiff test
  4. Clue cells on wet mount micro
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44
Q

Which HSV tends to affect only genitals

A

HSV 2

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45
Q

Recurrence of HSV 1

A

20-50% year 1, rapid decline after

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46
Q

Recurrence of HSV 2

A

70-90% have >1 recurrence
Average recurrence 4 a year
Slow decline in recurring, usually 3-5 years
25% increase in recurrence after yr 4

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47
Q

Frequency of asymp viral shedding in HSV 1

A

Infrequent

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48
Q

Frequency of asymp viral shedding in HSV 2

A

Frequent

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49
Q

Incubation period of herpes

A

2-14 days

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50
Q

Does HSV increase your risk of HIV infection

A

HSV 2 can increase infection and transmission

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51
Q

Is visible ulceration common in HSV proctitis

A

No
(HSV swab should always be done in MSM with proctitis)

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52
Q

Diagnostic gold standard for type specific HSV antibody

A

Western blot

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53
Q

What do HIV tests look for?

A

HIV antibodies and HIV antigens (p24 etc)

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54
Q

WP for 4th gen HIV serological test

A

18-45 days

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55
Q

Does someone who has had HIV seroconversion have to test +be for HIV

A

No, may test negative if seroconverts before 45 day window period

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56
Q

Does someone who has had HIV seroconversion have to test +ve for HIV

A

No, may test negative if seroconverts before 45 day window period

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57
Q

Window period of HIV POCT

A

90 days

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58
Q

Can you give a HIV positive result from one positive test

A

No, must be at least 2 positive results

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59
Q

Male to female GC transmission rate

A

50-90%

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60
Q

Female to male GC transmission rate

A

20% (60-80% after 4 exposures)

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61
Q

GC incubation in men

A

3-5 days

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62
Q

Male GC synptoms

A

Urethral discharge, (80%)
Dysuria (50%)

63
Q

Rectal GC symptoms

A

Asymp
Discharge (12%)
Pain (7%)

64
Q

GC asymp rates in women

A

50%

65
Q

Main GC pharyngeal symptom

A

Asymp

66
Q

Does rectal GC in women have to come.from anal sex

A

No, can come from vaginal secretions

67
Q

UK GC complication rate female

A

5-10%

68
Q

UK GC complication rate male

A

<1%

69
Q

Is GC diagnosis on microscopy final?

A

Presumptive - NAAT or culture still required

70
Q

gC micro sensitivity in women

A

60%

71
Q

What is nesseria meningitidis

A

Can be mistaken for GC on micro but can just be in genital tract

72
Q

Can a single positive extra-genital NAAT for GC be accepted alone

A

Repeat NAAT required

73
Q

When should pharyngeal GC sampling happen

A

MSM
Asia Pacific GC
Ceftriaxonen resistant GC

74
Q

How to differentiate GC subtypes

A

NG-MAST test

75
Q

How does GC acquire its abx resistance

A

Acquiring resistant plasmids
Point chromosome mutations

76
Q

How effective should first line GC abx be?

A

> 95%

77
Q

Second line GC tx

A

Oral cefixime plus oral azithromycin 2g

78
Q

Who should avoid oral cirpofloxacin

A

Adverse reaction to quinolones, on costicosteroids, kidney disease, transplant, over 60

79
Q

GC tx with ceph allergy

A

IM gent and azithromycin 2g

80
Q

Is ceftriaxone safe in pregnancy

A

Yes

81
Q

Is ceftriaxone safe in breastfeeding

A

Yes

82
Q

Are quinolones safe in pregnancy

A

No

83
Q

CT strain for occular CT

A

Serovars A-C

84
Q

What immune response clears CT

A

Vigorous TH1 lymphocyte response with production of bacteriocidal gamma interferon

85
Q

% of symptomatic men with CT

A

10

86
Q

What increases risk factor of sexualy acquired reactive arthritis from CT

A

HLA-B27 positive

87
Q

MGen co infection with CT rate

A

5-15%

88
Q

TOC for rectal CT

A

3 weeks

89
Q

CT looks back period

A

Symptoms - 4 weeks
Asymp - 6 months

90
Q

CT UK reinfection rates

A

21-29%

91
Q

CT contact positive test results rate

A

60-70%

92
Q

How does diaphragm use affect UTI rate

A

Decrease vaginal lactobacilli and increase e. Coli
Spermicides may inhibit hydrogen peroxide producing bacteria

93
Q

How does oestrogen affect utis

A

Low oestrogen predisposes to utis

94
Q

Gold standard ex for uti

A

Needle aspiration of bladder urine

95
Q

Most common bacterial UTI cause in uncomplicated cystitis in premenopausal women

A

E. Coli (70-95%)
Staph saphrophyticus (5-10%)

96
Q

Is a renal USS required in all acute uncomplicated pylonephritis cases

A

Yes

97
Q

Prophylactic management of UTIs in postmenopausal women

A

Oestrogen cream

98
Q

HSV-1 associated groups

A

Increasing age
Lower socio-economic status
Early age at first intercourse

99
Q

HSV-2 associated groups

A

Female
Lifetime no. Sexual partners
Ethnicity (southern hemisphere more.common)

100
Q

Percentage of HSV acquisition episodes which are symptomatic

A

30%

101
Q

Prior HSV 1 affects if get HSV 2

A

Less systemic symptoms
No change to no. Of outbreaks

102
Q

Length of time that asymptomatic HSV-2 virus sheds for

A

50% < 12 hours

103
Q

What increases HSV 2 shedding

A

Co-infection with HSV 1
immunocompromised
First year after acquisition
Around outbreaks
Being female

104
Q

Will never having sex while HSV lesions present prevent transmission

A

No

105
Q

Has stress been proven to affect HSV reoccurrences

A

No

106
Q

Alpha sub group herpes virus

A

Human herpes virus 1
Human herpes virus 2
Varicella zoster virus

107
Q

Beta subgroup herpes virus

A

Cytomegalovirus
Human herpes virus 6
Human herpes virus 7

108
Q

Gamma subgroup herpes virus

A

Epstein barr virus
Human herpes virus 8

109
Q

What makes up the structure of a herpes virus

A

Core of viral DNA
Nucleocapsid
Tegument
Envelope of viral+host glycoproteins

110
Q

Which herpes glycoprotein aids in immune escape?

A

gC

111
Q

What percentage of days does asymp shedding happen of hsv2 from an infected woman

A

3-5%

112
Q

Diseases caused by spirocheates

A

STS, yaws, pinta, Weil’s disease, relapsing fever, Vincent’s angina

113
Q

Commonest aerobic bacteria

A

E coli
Enterococci
Proteus
Klebsiella

114
Q

Most common anaerobic bacterial cause of utis

A

Bacteroides
Clostridia
Peptostreptococci

115
Q

Most common cause of breast abscesses

A

Actinomyces
Bacillus anearobes

116
Q

Optimal TV PH

A

4.9-7.5

117
Q

TV asymp rates

A

10-50%

118
Q

TV presentation in men

A

Discharge, dysuria, urethral irritation
Urinary frequency

119
Q

TV affects on pregnancy

A

Pre term delivery
Low birth weight

120
Q

TV spontaneous cure rate

A

20-25%

121
Q

TV pregnancy treatment

A

Metronidazole 500mg BD 7 days
No high dose metronidazole while pregnant or breastfeeding

122
Q

How does lactobacilli support the vaginal ph

A

Metabolised glycogen to produce lactic acid which keeps ph 3.5-4.5
Also produce other factors which inhibit growth of other organisms

123
Q

When is vaginal ph at it’s lowest

A

Mid cycle

124
Q

Alternative oral abx for BV

A

Clindamycin 300mg BD 5 days
Tinidazole 2g

125
Q

Alternative PV BV regiemes

A

0.75% metronidazole cream
2% clindamycin cream
Dequalinium chloride vaginal tablets

126
Q

Side effects of clindamycin cream/oral

A

Pseudomembranous colitis due to C Diff

127
Q

What major drugs may enhance metronidazole

A

Warfarin
Cimetidine

128
Q

All STIs increase risk of hiv. Which STIs increase the risk in particular

A

Ulcerative STIs
10-50x m-f
50-300x f-m

129
Q

When is highest hiv transmission rate from a woman

A

Pre and intermenstrual

130
Q

How does hiv gain entry to the body

A

Via a break in the mucosa or when a dendritic cell carries it across the barrier

131
Q

Which hepatitis virus is the only DNA virus

A

Hep b

132
Q

What is actinomyces

A

Gram positive filamentous, non acid fast (IE non spore forming) anearobic to micro aerobic bacilli

133
Q

Describe the herpes virus

A

Double stranded DNA incased within an icosahedral protein cage

134
Q

HSV suppression in pregnancy dose

A

400mg TDS from 36 weeks

135
Q

What is molluscum

A

Large DNA virus

136
Q

What is hep A

A

RNA picornavirus

137
Q

What is hep b

A

Small partially double stranded DNA virus

138
Q

What is hep c

A

Positive sense RNA virus

139
Q

What is PEP drugs (usually)

A

Tenofovir disoproxil 245mg/emtricitabine 200mg with raltegravir 1200mg

140
Q

PEP routine offer?

A
  • Receptive anal sex hiv status known + unknown
  • receptive vaginal sex with hiv +be
  • occupational exposure known hiv
  • injecting needle sharer known hiv
    If hiv known but viral load undetectable for >6 months pep not indicated
141
Q

When to consider PEP

A

Insertive vaginal sex with hiv +be partner
Insertive anal with hiv unknown status

142
Q

What to avoid while on raltegravir

A

Antacids with aluminium, magnesium, calcium
Multivitamins, iron supplements

143
Q

Mandatory tests for pep

A

Creatinine and egfr
ALT
HIV 1
Hep B
Preg test
Sti screen

144
Q

Pep for pregnant women

A

Tenofovir disoproxil 245mg/emtricitabine 200mg with raltegravir 400mg BD

145
Q

Is pep licensed in pregnancy

A

No

146
Q

Higher risk time for hiv transmission for women

A

Third trimester, post partum,
Period (theoretically)

147
Q

If further high risk sex is had while on pep, how long to continue pep for

A

MSM - 48 hours after last sex
Women etc - 7 days after

148
Q

How long for prep to become effective before and after injecting drugs

A

7 days before 7 days after

149
Q

What test to do if high risk of hiv acquisition in the last 4 weeks?

A

HIV viral load

150
Q

Who cannot use event based prep

A

Frontal/vaginal sex
Injecting drugs
Hep B positive

151
Q

BMD reduction in prep?

A

1.5-2% at hip and spine after 48 weeks treatment

152
Q

Prep NNT

A

13

153
Q

Why can MGen not be gram stained

A

Lacks a cell wall

154
Q

Size of mgen

A

480 kilobases - smallest self replicating bacterium