STI

Question 1

What is the cause of bacterial vaginosis?

Answer 1

Gardnerella vaginallis

Question 2

What is the damsel criteria for bacterial vaginosis?

Answer 2

1. Thin, white homogenous discharge
   clue cells on microscopy: stippled vaginal epithelial cells
2. Vaginal pH > 4.5
3. Positive whiff test (addition of potassium hydroxide results in fishy odour)

Question 3

How is bacterial vaginosis treated?

Answer 3

Metronidazole

70-80% initial cure rate
relapse rate > 50% within 3 months
the BNF suggests topical metronidazole or topical clindamycin as alternatives

Question 4

What is the buzz word for bacterial vaginosis?

Answer 4

Clue cells

Question 5

What is the complicating factor of bacterial vaginosis in pregnancy?

Answer 5

Risk in preterm labour, low birth weight and chorioamnionitis, late miscarriage

Question 6

Can metronidazole be used in pregnancy?

Answer 6

Yes.

Question 7

What are clue cells?

Answer 7

Clue cells - epithelial cells develop a stippled appearance due to being covered with bacteria

Question 8

How does trichomonas vaginalis differ from bacterial vaginosis?

Answer 8

BV:
- White discharge
- Clue cells

Both:
- pH > 4.5
- Offensive discharge

Trichomonas:
- Frothy yellow/green discharge
- Vulvovaginitis
- Strawberry cervix
- Wet mount: motile trophozoites

Question 9

What STI is caused by gram negative diplococcus?

Answer 9

Neisseria gonorrhoeae.

Question 10

What is the incubation period of gonorrhoaeae?

Answer 10

2-5 days

Question 11

What are the features of Neisseria gonorrhoeae?

Answer 11

Males: urethral discharge, dysuria
Females: cervicitis e.g. leading to vaginal discharge
rectal and pharyngeal infection is usually asymptomatic

Question 12

Why is gonorrhoea vaccination challenging?

Answer 12

antigen variation of type IV pili (proteins which adhere to surfaces) and Opa proteins (surface proteins which bind to receptors on immune cells)

Question 13

How is gonnorhoeae treated?

Answer 13

IM ceftriaxone 1 gram

Alertnative:
Oral cefixime 400mg (single dose) + oral azithromycin 2g (single dose)

Question 14

What are the most common causes of septic arthritis in young people?

Answer 14

Disseminated gonococcal infection (DGI) and gonococcal arthritis

Question 15

What are the features of a disseminated gonococcal infection? It’s a triad

Answer 15

Tenosynovitis
Migratory polyarthritis
Dermatitis (lesions can be maculopapular or vesicular)

Question 16

Why is doxycycline the new treatment for chlamydia?

Answer 16

Macrolide resistance

now preferred to azithromycin due to concerns about Mycoplasma genitalium. This infection is often coexistant in patients with Chlamydia and there is evidence of rising levels of macrolide resistance, hence why doxycycline is preferred

Question 17

What is the most prevalent STI in the UK?

Answer 17

Chlamydia

Question 18

What are the features of chlamydia?

Answer 18

women: cervicitis (discharge, bleeding), dysuria
men: urethral discharge, dysuria

Question 19

What are the complications of chlamydia?

Answer 19

epididymitis
pelvic inflammatory disease
endometritis
increased incidence of ectopic pregnancies
infertility
reactive arthritis
perihepatitis (Fitz-Hugh-Curtis syndrome)

Question 20

What are the first line investigations for chlamydia?

Answer 20

Female: Vulvalvaginal swb
Men: Urine test

Nucleic acid amplification testing

Question 21

How should chlamydia be treated?

Answer 21

Doxycycline

Question 22

How should someone who is pregnant be treated for chlamydia?

Answer 22

Erythromycin
Amoxicillin
Azithromycin (best choice)

Question 23

How should men with urethral symptoms be contact traced?

Answer 23

All contacts since, and in the four weeks prior to, the onset of symptoms

Question 24

How should women and asymptomatic men be contact traced?

Answer 24

All partners from the last six months or the most recent sexual partner should be contacted

Question 25

What are the features of genital herpes? What is the underlying infection?

Answer 25

Painful ulcers - Multiple Caused by HSV2 Primary attack associated with fevers and pain

Question 26

What is the feature of chancroid ulcer?

Answer 26

Genital ulcers associated with unilateral, painful inguinal lymph node enlargement. Ulcers typically have a sharply defined, ragged, undermined border.

Question 27

What causes a chancroid ulcer?

Answer 27

Haemophilus Ducreyi

Question 28

What are the phases of lymphogranuloma venereum? What is the causative agent?

Answer 28

stage 1: small painless pustule which later forms an ulcer stage 2: painful inguinal lymphadenopathy stage 3: proctocolitis Chlamydia trachoma's

Question 29

What is pelvic inflammatory disease?

Answer 29

inflammation of the female pelvic organs including the uterus, fallopian tubes, ovaries and the surrounding peritoneum *Usually from infection of endocervix

Question 30

What causes pelvic inflammatory disease?

Answer 30

Chlamydia trachomatis (Most common cause) Neisseria gonorrhoeae Mycoplasma genitalium Mycoplasma hominis

Question 31

What are the features of pelvic inflammatory disease?

Answer 31

Lower abdominal pain Fever Deep dyspareunia Dysuria and menstrual Vaginal or cervical discharge Cervical excitation

Question 32

What is the treatment for PID?

Answer 32

oral ofloxacin + oral metronidazole OR intramuscular ceftriaxone + oral doxycycline + oral metronidazole

Question 33

How do you test for syphilus?

Answer 33

1. Non- treponemal test: - Not specific for syphilis - based upon the reactivity of serum from infected patients to a cardiolipin-cholesterol-lecithin antigen assesses the quantity of antibodies -negative after treatment Tests: 1. rapid plasma reagin (RPR), and 2. Venereal Disease Research Laboratory (VDRL) 2. Treponemal specific test: - Specific to syphikus - Qualitative only and are reported as 'reactive' or 'non-reactive' - examples include: TP-EIA (T. pallidum enzyme immunoassay), TPHA (T. pallidum HaemAgglutination test)

Question 34

What does a Positive non-treponemal test + positive treponemal test mean?

Answer 34

Consistent with active infection

Question 35

What does a Positive non-treponemal test + negative treponemal test mean?

Answer 35

Consistent with false positive

Question 36

What does a Negative non-treponemal test + positive treponemal test mean?

Answer 36

Consistent with treated syphilus

Question 37

Can chlamydia be diagnosed by gram stain?

Answer 37

No - it does not gram stain

Question 38

What is the gram stain of gonorrhoea?

Answer 38

Gram negative diplococcus

Question 39

How do you treat trichinas vaginalis?

Answer 39

Oral metronidazole for 5-7 days, although the BNF also supports the use of a one-off dose of 2g metronidazole

Question 40

What is the gram stain of gardnerella?

Answer 40

Gardnerella vaginalis is a coccobacillus which can appear as both gram-positive or occasionally gram-negative due to its very thin wall.

Question 41

Painless penile ulcer + painful inguinal lymphadenopathy?

Answer 41

Lymphogranula venereum

Question 42

Painless penile ulcer + painless inguinal lymphadenopathy?

Answer 42

Syphilus

Question 43

What is non-specific urethritis?

Answer 43

Non-gonococcal urethritis (NGU, sometimes referred to as non-specific urethritis) is a term used to describe the presence of urethritis when a gonococcal bacteria are not identifiable or the initial swab.

Question 44

Causes of non-specific urethritis?

Answer 44

Chlamydia trachomatis - most common cause Mycoplasma genitalium - thought to cause more symptoms than Chlamydia

Question 45

Management of non-specific urethritis?

Answer 45

Doxycycline or azithromycin

Question 46

What is the cause of multiple painless genital ulcers, known as granuloma inguinale?

Answer 46

Klebsiella granulomatos