STIs Flashcards
(154 cards)
1
Q
Pregnancy treatment of C4
A
Amoxicillin, erithromycin, azithromycin
2
Q
% of asymp CT
A
50% men and 70% women
3
Q
What is CT bacteria
A
Obligate intracellular human parasite
4
Q
Life cycle length of CT
A
48-72 hours
5
Q
How does CT enter a cell
A
Endocytosis
6
Q
CT life cycle
A
- Infectious elementary body attaches via endocytosis
- Differentiates into larger replicating bodies
- Inclusion membrane formed
- EBs form in inclusion membrane
- Cells lyase and release CT
7
Q
Test of choice for CT
A
NAAT
8
Q
What temp.for.NAAT storage
A
Room temp
9
Q
CT NAAT turn around
A
2-3 days
10
Q
Are NAATs approved for extra-genital sampling
A
No.
Does appear to work well for it however.
11
Q
NAAT limitation
A
- DNA contamination
- Inhibition of assay
- Detection of non viable organism
12
Q
Positive predictive value of CT Naat
A
> 95%
13
Q
Where is new variant CT most common
A
Sweden
14
Q
Most at risk group of LGV
A
MSM (and HIV)
15
Q
CT TOC time?
A
5 weeks
(6 weeks if azithromycin)
16
Q
Why must TV micro be done immediately
A
20% lose motility in 10 minutes
17
Q
What TV test cannot be used for men
A
Direct antigen POC test
18
Q
Most successful chance of TV culture
A
Direct innoculation to growth medium
19
Q
Hallmark of trichomonads?
A
Characteristic tumbling motility
20
Q
Best stain for TV?
A
Acridine orange
21
Q
Sensitivity of wet microscopy for TV
A
45-60% in women
Lower in men
22
Q
Highest sensitivity test for tv
A
NAAT (88-97%)
23
Q
NAAT specifity for TV
A
98-99%
24
Q
Male NAAT sensitivity TV
A
Urine 74%
Swab 95%
25
TV window period
10 days
26
Culture plate for thrush
Sabourauds medium
27
Direct microscopy signs of candida
Gram positive spores
Pseudohyphae
28
Steps to dry microcoscopy
1. Fix with heat
2. Stain with violet
3. Aqueous iodine
4. Decolourise with acetone
5. Red counterstain
29
Sensitivity of thrush slide
Gram stain - 65%
Wet - 40-60%, specific
30
Accuracy of germ tube formation for candida albicans
>95%
31
Rate of non-albicans in vvc cases
5-10%
32
Asymp Candida rates?
20% non pregnant
40% pregnant
33
Most common cause of recurrent thrush
Candida albicans
34
When is repeat testing for thrush indicated
After treatment of persistent non-albicans infection.
Cure is 2 neg cultures at least 7 days apart
35
How many of Amsels criteria to diagnose BV
3 of 4
36
Normal vaginal ph
4.5
37
Vaginal.ph in BV
Greater than 4.5
38
Factors that elevate vaginal PH
BV
TV
Sperm
Menses
39
What is used to perform.whiff test for BV
10% KOH
40
What is Zheil neelsen staining used for
TB and leprosy
41
What colour do gram stained bacteria go
Gram +ve purple
Gram -ve red/pink
42
What is the Ison-Hay grading for
Vaginal flora (grades 0-4)
Grade 3 is BV
43
What is Amsels criteria
1. Thin homogeneous vaginal discharge
2. Vaginal ph > 4.5
3. Positive whiff test
4. Clue cells on wet mount micro
44
Which HSV tends to affect only genitals
HSV 2
45
Recurrence of HSV 1
20-50% year 1, rapid decline after
46
Recurrence of HSV 2
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
47
Frequency of asymp viral shedding in HSV 1
Infrequent
48
Frequency of asymp viral shedding in HSV 2
Frequent
49
Incubation period of herpes
2-14 days
50
Does HSV increase your risk of HIV infection
HSV 2 can increase infection and transmission
51
Is visible ulceration common in HSV proctitis
No
(HSV swab should always be done in MSM with proctitis)
52
Diagnostic gold standard for type specific HSV antibody
Western blot
53
What do HIV tests look for?
HIV antibodies and HIV antigens (p24 etc)
54
WP for 4th gen HIV serological test
18-45 days
55
Does someone who has had HIV seroconversion have to test +be for HIV
No, may test negative if seroconverts before 45 day window period
56
Does someone who has had HIV seroconversion have to test +ve for HIV
No, may test negative if seroconverts before 45 day window period
57
Window period of HIV POCT
90 days
58
Can you give a HIV positive result from one positive test
No, must be at least 2 positive results
59
Male to female GC transmission rate
50-90%
60
Female to male GC transmission rate
20% (60-80% after 4 exposures)
61
GC incubation in men
3-5 days
62
Male GC synptoms
Urethral discharge, (80%)
Dysuria (50%)
63
Rectal GC symptoms
Asymp
Discharge (12%)
Pain (7%)
64
GC asymp rates in women
50%
65
Main GC pharyngeal symptom
Asymp
66
Does rectal GC in women have to come.from anal sex
No, can come from vaginal secretions
67
UK GC complication rate female
5-10%
68
UK GC complication rate male
<1%
69
Is GC diagnosis on microscopy final?
Presumptive - NAAT or culture still required
70
gC micro sensitivity in women
60%
71
What is nesseria meningitidis
Can be mistaken for GC on micro but can just be in genital tract
72
Can a single positive extra-genital NAAT for GC be accepted alone
Repeat NAAT required
73
When should pharyngeal GC sampling happen
MSM
Asia Pacific GC
Ceftriaxonen resistant GC
74
How to differentiate GC subtypes
NG-MAST test
75
How does GC acquire its abx resistance
Acquiring resistant plasmids
Point chromosome mutations
76
How effective should first line GC abx be?
>95%
77
Second line GC tx
Oral cefixime plus oral azithromycin 2g
78
Who should avoid oral cirpofloxacin
Adverse reaction to quinolones, on costicosteroids, kidney disease, transplant, over 60
79
GC tx with ceph allergy
IM gent and azithromycin 2g
80
Is ceftriaxone safe in pregnancy
Yes
81
Is ceftriaxone safe in breastfeeding
Yes
82
Are quinolones safe in pregnancy
No
83
CT strain for occular CT
Serovars A-C
84
What immune response clears CT
Vigorous TH1 lymphocyte response with production of bacteriocidal gamma interferon
85
% of symptomatic men with CT
10
86
What increases risk factor of sexualy acquired reactive arthritis from CT
HLA-B27 positive
87
MGen co infection with CT rate
5-15%
88
TOC for rectal CT
3 weeks
89
CT looks back period
Symptoms - 4 weeks
Asymp - 6 months
90
CT UK reinfection rates
21-29%
91
CT contact positive test results rate
60-70%
92
How does diaphragm use affect UTI rate
Decrease vaginal lactobacilli and increase e. Coli
Spermicides may inhibit hydrogen peroxide producing bacteria
93
How does oestrogen affect utis
Low oestrogen predisposes to utis
94
Gold standard ex for uti
Needle aspiration of bladder urine
95
Most common bacterial UTI cause in uncomplicated cystitis in premenopausal women
E. Coli (70-95%)
Staph saphrophyticus (5-10%)
96
Is a renal USS required in all acute uncomplicated pylonephritis cases
Yes
97
Prophylactic management of UTIs in postmenopausal women
Oestrogen cream
98
HSV-1 associated groups
Increasing age
Lower socio-economic status
Early age at first intercourse
99
HSV-2 associated groups
Female
Lifetime no. Sexual partners
Ethnicity (southern hemisphere more.common)
100
Percentage of HSV acquisition episodes which are symptomatic
30%
101
Prior HSV 1 affects if get HSV 2
Less systemic symptoms
No change to no. Of outbreaks
102
Length of time that asymptomatic HSV-2 virus sheds for
50% < 12 hours
103
What increases HSV 2 shedding
Co-infection with HSV 1
immunocompromised
First year after acquisition
Around outbreaks
Being female
104
Will never having sex while HSV lesions present prevent transmission
No
105
Has stress been proven to affect HSV reoccurrences
No
106
Alpha sub group herpes virus
Human herpes virus 1
Human herpes virus 2
Varicella zoster virus
107
Beta subgroup herpes virus
Cytomegalovirus
Human herpes virus 6
Human herpes virus 7
108
Gamma subgroup herpes virus
Epstein barr virus
Human herpes virus 8
109
What makes up the structure of a herpes virus
Core of viral DNA
Nucleocapsid
Tegument
Envelope of viral+host glycoproteins
110
Which herpes glycoprotein aids in immune escape?
gC
111
What percentage of days does asymp shedding happen of hsv2 from an infected woman
3-5%
112
Diseases caused by spirocheates
STS, yaws, pinta, Weil's disease, relapsing fever, Vincent's angina
113
Commonest aerobic bacteria
E coli
Enterococci
Proteus
Klebsiella
114
Most common anaerobic bacterial cause of utis
Bacteroides
Clostridia
Peptostreptococci
115
Most common cause of breast abscesses
Actinomyces
Bacillus anearobes
116
Optimal TV PH
4.9-7.5
117
TV asymp rates
10-50%
118
TV presentation in men
Discharge, dysuria, urethral irritation
Urinary frequency
119
TV affects on pregnancy
Pre term delivery
Low birth weight
120
TV spontaneous cure rate
20-25%
121
TV pregnancy treatment
Metronidazole 500mg BD 7 days
No high dose metronidazole while pregnant or breastfeeding
122
How does lactobacilli support the vaginal ph
Metabolised glycogen to produce lactic acid which keeps ph 3.5-4.5
Also produce other factors which inhibit growth of other organisms
123
When is vaginal ph at it's lowest
Mid cycle
124
Alternative oral abx for BV
Clindamycin 300mg BD 5 days
Tinidazole 2g
125
Alternative PV BV regiemes
0.75% metronidazole cream
2% clindamycin cream
Dequalinium chloride vaginal tablets
126
Side effects of clindamycin cream/oral
Pseudomembranous colitis due to C Diff
127
What major drugs may enhance metronidazole
Warfarin
Cimetidine
128
All STIs increase risk of hiv. Which STIs increase the risk in particular
Ulcerative STIs
10-50x m-f
50-300x f-m
129
When is highest hiv transmission rate from a woman
Pre and intermenstrual
130
How does hiv gain entry to the body
Via a break in the mucosa or when a dendritic cell carries it across the barrier
131
Which hepatitis virus is the only DNA virus
Hep b
132
What is actinomyces
Gram positive filamentous, non acid fast (IE non spore forming) anearobic to micro aerobic bacilli
133
Describe the herpes virus
Double stranded DNA incased within an icosahedral protein cage
134
HSV suppression in pregnancy dose
400mg TDS from 36 weeks
135
What is molluscum
Large DNA virus
136
What is hep A
RNA picornavirus
137
What is hep b
Small partially double stranded DNA virus
138
What is hep c
Positive sense RNA virus
139
What is PEP drugs (usually)
Tenofovir disoproxil 245mg/emtricitabine 200mg with raltegravir 1200mg
140
PEP routine offer?
- 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
When to consider PEP
Insertive vaginal sex with hiv +be partner
Insertive anal with hiv unknown status
142
What to avoid while on raltegravir
Antacids with aluminium, magnesium, calcium
Multivitamins, iron supplements
143
Mandatory tests for pep
Creatinine and egfr
ALT
HIV 1
Hep B
Preg test
Sti screen
144
Pep for pregnant women
Tenofovir disoproxil 245mg/emtricitabine 200mg with raltegravir 400mg BD
145
Is pep licensed in pregnancy
No
146
Higher risk time for hiv transmission for women
Third trimester, post partum,
Period (theoretically)
147
If further high risk sex is had while on pep, how long to continue pep for
MSM - 48 hours after last sex
Women etc - 7 days after
148
How long for prep to become effective before and after injecting drugs
7 days before 7 days after
149
What test to do if high risk of hiv acquisition in the last 4 weeks?
HIV viral load
150
Who cannot use event based prep
Frontal/vaginal sex
Injecting drugs
Hep B positive
151
BMD reduction in prep?
1.5-2% at hip and spine after 48 weeks treatment
152
Prep NNT
13
153
Why can MGen not be gram stained
Lacks a cell wall
154
Size of mgen
480 kilobases - smallest self replicating bacterium
