JC105 (O&G) - Obstetric and gynaecological infections

Question 1

List natural immune defenses in the female genital tract

Answer 1

 Apposition of labia & vaginal walls

 Stratified squamous epithelium in lower genital tract (natural resistance to infection)

 Vaginal microbiome (especially lactobacilli)

 Vaginal acidity (pH 3.5-4.5)

Question 2

Factors that adversely affect immune defense in the female genital tract

Answer 2

Menstrual cycle – secretions (alkaline) around menses

Pregnancy & puerperium:
 high pH
 Higher estrogen levels and higher glycogen content in vaginal secretions
 Trauma at delivery  infection in lower genital tract
 Lochia (alkaline) – heavy flow of blood and mucus that starts after delivery

Diabetes

Antibiotics

Question 3

Non-infectious causes of vaginal discharge

Answer 3

 Physiological (hormones)
 Cervical ectropian
 Foreign bodies (IUCD, ring pessary for prolapse)
 Vulval dermatitis
 Benign and malignant tumours (cervical cancer)

Question 4

Infectious causes of vaginal discharge

Answer 4

Non-sexually transmitted
 Bacterial vaginosis
 Candidiasis
 Group B Streptococcus

Sexually transmitted
 Chlamydia trachomatis
 Neisseria gonorrhea
 Trichomonas vaginalis

Question 5

Outline history taking questions for vaginal discharge

Answer 5

History: Differentiate between physiological vs. pathological discharge
 Timing of discharge
 Smell, color, character

 Associated symptoms, e.g. abdominal pain, fever, pruritus
 Contraception (IUCD - non-infectious cause of vaginal discharge)

 Past health (diabetes)
 Cervical smear (up to date? Normal?)

 Previous obstetrics history

Question 6

Top 5 STDs in Hong Kong

Answer 6

1. Non-gonococcal urethritis/ nonspecific genital infection
2. Genital warts/ condyloma acuminatum - HPV
3. Gonorhoea
4. Syphilis
5. Herpes genitalis

Question 7

Follow-up tests, referrals and plan of action after STI diagnosis

Answer 7

Present illness:
 Screen for other STIs (HIV, VDRL)
 Treatment (appropriate and prompt)

Sex partner:
 Partner(s) referral (to social health clinics) & treatment
 Safer sex education (e.g. barrier method)

Gynaecological:
 Special consideration during pregnancy (treat to prevent preterm labor; use safe antibiotics for babies)
 Cervical smear (opportunistic screening)
 Counselling on possible sequaelae

Question 8

Pelvic inflammatory disease

• Structures infected
• Routes of infection
• Causative organisms

Answer 8

pelvic infection:
 Infection of the uterus, fallopian tubes, adjacent parametria & overlying peritoneum
 Does not include lower genital tract (vulval/ vaginal infection)

Route of infection:

1. Ascending – from the lower genital tract (most common)
2. From nearby organs, e.g. acute appendicitis
3. Haematological route

Causative organisms:
 Sexually transmitted: Chlamydia trachomatis, Neisseria gonorrhoeae
 Aerobic organisms: staphylococci, streptococci, coliforms, Haemophilus influenzae
 Anaerobic organisms: Clostridium sp., bacteroides, peptococci, streptopeptococci
 Others (less common): Mycobacterium tuberculosis, Actinomyces…etc

Question 9

Pelvic inflammatory disease

• Risk factors

Answer 9

Risk factors: 
 Existing lower genital tract infection/ hematogenous infection
 Risky sexual behaviour
 Post-abortal
 Puerperium
 Following surgery
 IUCD insertion (first 2-4 weeks)
 Previous history of PID

Question 10

Pelvic inflammatory disease

- S/S

Answer 10

Symptoms: 
 Abdominal pain
 Fever
 Vaginal discharge/ abnormal uterine bleeding
 Urinary symptoms
 GI symptoms

Signs:
 Fever, BP, pulse (hypotension and tachycardia can indicate severe sepsis)
 Abdomen: signs of peritonitis (severe disease, or other DDx)
 Vagina: hot, discharge
 Cervical excitation tenderness
 Uterine & adnexal tenderness
 Adnexal mass (tubo-ovarian complex/abscess)

Question 11

Describe the patient presentation that needs presumptive Dx of PID and early treatment

Answer 11

 Sexually active women experiencing pelvic/ lower abdominal pain
 In the absence of other cause
 With cervical motion/ uterine/ adnexal tenderness

Question 12

Ddx of pelvic inflammatory disease

Answer 12

 Ectopic pregnancy
 Ovarian cyst complication
 Urinary tract infection
 Acute appendicitis

Question 13

First-line investigations for PID

Answer 13

Blood: CBP – leukocytosis, (+/- inflammatory markers: ESR, CRP)

Microbiology:
 Endocervical swabs: Chlamydia (IF + culture), gonococcus (culture)
 High vaginal swabs: trichomonas (microscopy, culture)
 Blood: VDRL (syphilis), HIV-Ab
 MSU: UTI
 Cervical pap smear

Additional
 Pregnancy test (exclude ectopic pregnancy)
 USG or MRI pelvis: ovarian cyst complications

Question 14

Outpatient treatment options for Pelvic inflammatory disease

Answer 14

Recommended:
1. IM ceftriaxone + oral doxycycline + oral metronidazole
Alternative:
2. Oral Ofloxacin + oral metronidazole (high ride effects)
3. Oral moxifloxacin (best against M. genitalium infection)
4. Intramuscular ceftriaxone + oral azithromycin (last-line)

Indications for adding metronidazole:
 Evidence/ suspicion of vaginitis (Trichomonas); or
 The patient underwent gynecologic instrumentation in the
preceding 2-3 weeks

Question 15

Inpatient treatment option for PID

Answer 15

Continue intravenous antibiotic until 24 hours after clinical improvement  follow by oral therapy

First-line:
IV Ceftriaxone + Oral antibiotics
Follow by: Oral doxycycline or oral metronidazole

Alternatives:

• IV cefoxitin
• IV augmentin + IV doxycycline
• IV clindamycin/ IV Gentamicin + oral clindamycin or oral metronidazole

Question 16

Indications for inpatient treatment of PID

Answer 16

 Cannot exclude surgical emergency
 Clinically severe disease
 Tubo-ovarian abscess complication (adnexal mass)
 PID in pregnancy
 Lack of response to oral therapy
 Intolerance to oral therapy

Question 17

Last-resort treatment options for PID refractory to medication

Answer 17

Surgical intervention for tubo-ovarian abscess not responding to antibiotrics (image-guided drainage/ laparoscopy/ laparotomy)

Remove IUD (controversial):
 Consider if no clinical improvement occurs within 48-72 hours of treatment
 Balance against the risk of pregnancy in those who have had otherwise unprotected intercourse in the preceding 7 days

Treat male partners of women with PID empirically with doxycycline,

Question 18

Complications of PID

Answer 18

Early:
 Tubo-ovarian abscess
 Septic shock

Late: 
 Recurrent PID
 Chronic pelvic pain (15-20%): dysmenorrhoea, dyspareunia
 Fitz-Hugh-Curtis syndrome
 Ectopic pregnancy
 Subfertility (tubal obstruction)

Question 19

Prevention methods of recurrent PID

Answer 19

 Education (avoid risky sexual behavior)

 Contraception (barrier methods, e.g. condom)

 Prompt diagnosis and treatment

 Contact tracing and treatment

Question 20

List 3 Non-sexually transmitted disease that cause vaginal discharge

Answer 20

Bacterial vaginosis

Vulvovaginal candidiasis/ Candida vulvovaginitis

Group B Streptococcus(GBS) infection

Question 21

Bacterial vaginosis

• Prevalence
• Causative pathogens
• Risk factors
• Type of discharge and presentation

Answer 21

commonest cause of vaginal discharge in reproductive aged women

Pathogens: Mainly anaerobes (Gardnerella vaginalis, Prevotella sp., Mycoplasma hominis, Mobiliuncus sp.)

Risk factors: 
 Black
 IUCD
 Smokers
 Antibiotics
 Sex

Types of discharge:

• offensive, fishy-smelling
• Thin, white, homogeneous discharge coating vaginal wall/ vestibule
• Not usually associated with vulvo-vaginitis

Question 22

Bacterial vaginosis

Complications

Answer 22

Infections:
 PID
 Post-TOP endometritis

Pregnancy-related:
 Late miscarriage
 Preterm labour
 PPROM (Preterm premature rupture of the membranes, pregnancy complication)
 Postpartum endometritis

Iatrogenic:
 Vaginal cuff cellulitis and abscess after vaginal hysterectomy

Question 23

Bacterial vaginosis

Diagnostic tests

Answer 23

Amsel’s criteria (3 out of 4): indicate high vaginal swab

1. Thin, white homogeneous discharge
2. Clue cells on microscopy
3. pH of vaginal fluid >4.5
4. Release of fishy odour on adding alkali (10% KOH) (‘whiff’ test positive)

Question 24

Bacterial vaginosis

• management options

Answer 24

General:
Advice against vaginal douching/ use of shower gels/ antiseptic bath agents

Antibiotics: 
Indications:
 Symptomatic women
 Those undergoing surgery
 Pregnant women
Options: 
- Oral metronidazole (non-breastfeeding)
- Intravaginal gel (breastfeeding)
- CLindamycin cream

Question 25

Vulvovaginal candidiasis/ Candida vulvovaginitis Causative pathogens Risk factors Vaginal discharge and presentation

Answer 25

Pathogen: Candida albicans ``` Risk factors: change defense mechanism of vagina  Pregnancy  Diabetes, immunosuppression  Oral contraceptive pills  Broad spectrum antibiotics ``` Presentation: - thick, white/yellow, cheesy - Vulvovaginitis: pruritus vulvae, soreness - Erythema of vulva, vagina - May cause skin fissure

Question 26

Vulvovaginal candidiasis/ Candida vulvovaginitis Diagnostic tests

Answer 26

Vaginal swab from vaginal fornix (vaginal discharge/ scraping from vulvar lesions) for: 1. Microscopic examination: mix with saline and wet mount - Slings of pseudohyphae of Candida albicans surrounded by round vaginal epithelial cells - Blastospores, conidia 2. ± culture for complicated cases: severe symptoms, pregnancy, abnormal host, non-albicans, recurrent

Question 27

Vulvovaginal candidiasis/ Candida vulvovaginitis Treatment options

Answer 27

asymptomatic: no need Symptomatic 1. Genital hygiene:  Keep genital area clean and dry  Avoid tight fitting synthetic clothing  Avoid local irritants in vulvovaginal area, e.g. perfumed products  Use vulval moisturisers as soap substitute, and regular skin conditioner 2. Antifungal agents, e.g. clotrimazole, econazole, miconazole:  Topical, oral (e.g. clotrimazole pessary 200 mg for 3 nights)  Vaginal route for pregnant women Maintenance therapy for recurrent candidiasis (rare)

Question 28

Group B Streptococcus(GBS) infection of female genital tract - Causative pathogen - Vaginal discharge and presentation - Complications

Answer 28

Causative pathogen: Streptococcus agalactiae (primary reservoir in GIT) Presentation: yellow or green discharge, vaginal burning and/or irritation Complications: Maternal risks:  UTI  PROM / PPROM (premature rupture of membranes = PROM before 37 weeks)  Preterm labour  Chorioamnionitis (associated with prolonged labor)  Post-partum endometritis Neonatal infection: - Early vertical infection: Septicaemia, pneumonia, respiratory failure, death - Late vertical/ horizontal infection: Meningitis, pneumonia

Question 29

GBS infection of female genital tract - DIagnostic tests in pregnant women - Indication for testing

Answer 29

Universal Group B Streptococcus screening: - low vaginal and rectal swab at 35-37 weeks Not required if:  Required intrapartum antibiotic prophylaxis; or  Planned for caesarean section

Question 30

GBS infection of female genital tract Treatment options Effectiveness

Answer 30

Intrapartum antibiotic prophylaxis (during labor): - Penicillin G/ benzyl penicillin Alternatives to penicillin: - cefazolin/ clindamycin/ erythromycin/ vancomycin Effectiveness: - Prevents early-onset GBS infection (not 100%) - Cannot prevent late-onset GBS infection/ horizontal infections

Question 31

Chlamydial infections in women - Causative pathogen - Risk factors - Incubation period - Presentation

Answer 31

Pathogen: Chlamydia trachomatis (obligate intracellular gram negative bacterium) Risk factors:  Young age  Multisexual partners, unsafe sex, low socioeconomic class  History of STD/ PID Incubation: 7-21 days Presentation: Most asymptomatic - Dysuria - Abnormal vaginal Mucopurulent discharge - Intermenstrual or postcoital bleeding - Deep dyspareunia - Lower abdominal pain - Cervicitis +/- contact bleeding (Men: Urethritis, Dysuria, Urethral discharge, Epididymo-orchitis)

Question 32

Chlamydial infections Complications

Answer 32

 PID  Chronic pelvic pain ``` Pregnancy:  Increased risk of ectopic pregnancy  Subfertility  Preterm labour  PPROM  Low birth weight  Post-partum endometritis ``` Syndromes:  Reiter’s Syndrome – urethritis, conjunctivitis and arthritis  Fitz-Hugh-Curtis Syndrome: perihepatitis/ perihepatic adhesions seen in laparotomy Complication in babies:  Conjunctivitis (5-12 days)  Pneumonitis (2-3 weeks)

Question 33

Chlamydial infections Diagnostic tests

Answer 33

Endocervical swab and/or first void urine:  Immunofluorescence  Culture (McCoy cell line)  PCR, ligase chain reaction  ELISA: Monoclonal Chlamydia-specific antibodies

Question 34

Chlamydial infections Treatment options

Answer 34

Recommended: - Doxycycline (100 mg bd for 7 days) Alternative for Allergic/ intolerant/ pregnancy: - azithromycin (1g oral single dose, then 500mg daily for 2 days) - erythromycin - amoxicillin 2. Screen for other STD 3. Contact tracing and treatment 4. Test of cure - Recommended in pregnancy (implication in newborn)

Question 35

Gonorrhea - Causative organism - Risk factors - Incubation period - Presentation

Answer 35

Neisseria gonorrhoeae:  Gram-negative diplococci Risk factors:  Multisexual partners, unsafe sex, low socioeconomic class  History of STD/ PID Incubation period: 10 days ``` Presentation:  yellow- green vaginal discharge  Dysuria, frequency  Vaginal pruritus, burning  Post-coital bleeding Speculum exam:  Vaginal erythema  Vulval swelling/ pain – Bartholin’s abscess ```

Question 36

Gonorrhea Complications in women

Answer 36

 PID  Chronic pelvic pain  Increased risk of ectopic pregnancy  Subfertility ``` Systemic involvement:  Arthritis, conjunctivitis, urethritis  Pharyngitis  Proctitis  Endocarditis  Meningitis  Disseminated gonococcal infection (rare) ``` ``` Pregnancy:  Miscarriage  Premature labour  PPROM  Chorioamnionitis  SGA (small for gestational age)  Stillbirth  Post-partum endometritis and pelvic sepsis ``` ``` Baby: Ophthalmia neonatorum (first few days of life) ```

Question 37

Gonorrhea Diagnostic test

Answer 37

Endocervical, urethral, anal, pharyngeal swabs:  Microscopy: Gram-negative diplococci  Culture (Thayer-Martin medium, Martin-Lewis medium)  PCR for DNA

Question 38

Gonorrhea Treatment options

Answer 38

1. Recommended within 14 days of exposure: IM ceftriaxone Alternatives: - Ciprofloxacin if C/ST shows sensitive - IM ceftriaxone + azithromycin - IM spectinomycin + azithromycin * * do not use quinolone due to pregnancy S/E and high resistance** 2. Screen for other STD 3. Contact tracing 4. Test of cure for all cases

Question 39

Trichomoniasis - Causative pathogen - Risk factors - Presentation - Complications

Answer 39

Pathogen: Trichomonas vaginalis (flagellated protozoal parasite) ``` Risk factors:  Smokers  Afro-Caribbean/ African race  Lower educational level, unsafe sex, multiple sexual partners ``` Presentation: - Foul smell, frothy, yellowish-green - Vaginitis: usually present with pruritus, soreness, dyspareunia - Post-coital bleeding (in pregnant women) Speculum: Strawberry cervix Pregnancy Cx:  Preterm birth  Low birth weight

Question 40

Trichomoniasis Diagnostic tests

Answer 40

High vaginal swab - Wet mount for microscopy: motile parasites - Culture (7 days) - Rapid antigen test (immunofluorescence, enzyme immunoassay) - Nucleic acid amplification tests (NAAT): detect rRNA - PCR

Question 41

Trichomoniasis Treatment options

Answer 41

For symptomatic women: 1. Metronidazole (oral) for 5-7 days or single high dose (Avoid high dose if pregnant/ breast feeding) 2. Screen for other STDs 3. Screen and treat partner 4. Test of cure if symptomatic despite Tx/ recurrence