Armando Hasudungan
Biology and Medicine videos

Sexual Transmitted Infection

Definitions
STI:
Infections that can be spread during sexual contact, some infections like herpes and warts can also be transmitted by skin to skin contact
Contraception: Deliberate use of artificial methods or other techniques to prevent pregnancy as a consequence of sexual intercourse. Methods include barrier methods, contraceptive pill and intrauterine devices. Only the barrier method can prevent STIs
Sex Protection: Safe sex is having sexual contact while protecting yourself and your sexual partner against sexually transmissible infections (STIs) and unplanned pregnancy.
Vaginal swab: First-line investigation for suspicion of STI. You can perform high vaginal swab, low vaginal swab or swab from the cervix itself.
Nucleic acid amplification test: Nucleic acid amplification is a valuable molecular tool not only in basic research but also in application oriented fields, such as clinical medicine development, infectious diseases diagnosis, gene cloning and industrial quality control. Polymerase chain reaction (PCR) was the first nucleic acid amplification method developed and until now has been the method of choice.
PCR: Polymerase chain reaction (PCR) was the first nucleic acid amplification method developed.
Pap smear: Quick and simple test used to check for changes to the cells of the cervix that may lead to cervical cancer.

Introduction Sexually transmitted infections (STI) are a significant public health worldwide. STI can result in chronic disease, pregnancy complications, infertility, and even death. Globally, congenital syphilis is still a leading cause of stillbirth and neonatal death. Antibiotic-resistant Neisseria gonorrhoeae continues to be a significant public health concern. Chlamydia trachomatis infection is the most frequently reported sexually transmitted infectious disease in the United States and continues to be an important risk factor for pelvic inflammatory disease (PID), ectopic pregnancies, urethritis, cervicitis, chronic pelvic pain, and infertility. Treatment of STDs should also include treatment of patients’ partners. Overall, patients, especially the younger population, should be screened regularly and counselled to ensure early diagnosis and treatment. Contraception does not prevent STI, protection such as condoms do.

Remember Premenarche female with signs of STD – sexual abuse?
Notifiable STI in Australia
Chlamydia
Donovanosis
Gonorrhoea
Syphilis
Hepatitis
HIV

Clinical Presentation 

  • Ulcers, rash, itch around genitals
  • Intermenstrual bleeding or post-coital bleeding
  • Low abdominal pain
  • Dyspareunia
  • Dysuria
  • Discharge – different, non-physiological
Characteristic of common cause of vaginal discharge
 Appearence  Smell Itch 
Physiological Clear/white, mucoid
Foreign body Grey or bloody, purulent Offensive
Malignancy Bloody, watery Offensive
Bacterial Vaginosis Grey, watery Offensive Itchy
Trichomonas Green, frothy Offensive  –
Candidasis Curd like (cheesy) Itchy
Gonococcal Green, watery  –

 

Risk Factors
Unprotected intercourse without male or female condom use
Unprotected mouth-to-genital contact
Early sexual activity, especially before age 18
Having multiple sex partners
Having a high-risk partner (one who has multiple sex partners or other risk factors)
Having anal sex or a partner who does
Alcohol and Illicit Drug use
Exchange of sex (sex work) for drugs or money

Approach

  • History
    • Sexual History and partners over the past 12months
    • Past STI
    • Assess Risk factors
  • Examination
  • Investigation
    • Swab (should be done at presentation)
Remember It is important to note notifiable sexually transmitted infections and also CONTACT TRACING!
Side note Although initial treatment of simple infection may be appropriate without culture, symptomatology can be variable and the gold standard should be a positive culture and sensitivity, especially with persistent or recurrent symptoms

 

Pubic lice

Overview

  • Pubic lice also known as pthirus pubis is a six-legged insect
  • Commonly live in pubic hair areas including armpit.
  • Can be transmitted during sexual intercourse or through shared clothes/sheets

Diagnosis

  • Identification of the adult lice or their egg (nits) in the affects area

Treatment

Trichomonas

Overview

  • Trichomonas vaginalis
  • Flagellated protozoan
  • Cervix may have a strawberry appearence (from punctate haemorrhage)

Clinical Presentation

  • Asymptomatic (majority)
  • Vaginal discharge
  • Vulval itching and soreness
  • Dysuria
Characteristic of common cause of vaginal discharge
 Appearence  Smell Itch 
Physiological Clear/white, mucoid
Foreign body Grey or bloody, purulent Offensive
Malignancy Bloody, watery Offensive
Bacterial Vaginosis Grey, watery Offensive Itchy
Trichomonas Green, frothy Offensive  –
Candidasis Curd like (cheesy) Itchy
Gonococcal  Green, watery  –

Diagnosis

  • Vaginal swab → Microscopy on wet smear (normal saline) or acridine orange stained slide
  • Culture vaginal swab
  • Vaginal Swab/cervical swab → nucleic acid amplification test (gold standard)

Treatment

  • Metronidazole
  • Partner must be contacted and tested/treated
Pharmacology Metronidazole is a prodrug. Unionized metronidazole is selective for anaerobic bacteria due to their ability to intracellularly reduce metronidazole to its active form. This reduced metronidazole then covalently binds to DNA, disrupt its helical structure, inhibiting bacterial nucleic acid synthesis and resulting in bacterial cell death. Metronidazole is used against protozoa such as Trichomonas vaginalis, amebiasis, and giardiasis. Metronidazole is extremely effective against anaerobic bacterial infections and is also used to treat Crohn’s disease, antibiotic-associated diarrhea, and rosacea.

Complications

  • ↑HIV transmission
Side Note In pregnancy Trichomonas infection is associated with preterm delivery and low birth weight baby

Chlamydia

Overview

  • Chlamydia trachomatis
  • Gram-negative bacterium that lives as an obligate intracellular parasite
  • Most common STI
  • Coinfection with neisseria gonorrhoea

Clinical Presentation

  • Asymptomatic (70% of cases)
  • Dysuria
  • Vaginal discharge
  • Irregular menstrual bleeding

Diagnosis

  • Vaginal Swab/cervical swab → Gram stain
    • Presence of pink “gram -ve”
  • Vaginal Swab/cervical swab → Culture
  • Vaginal Swab/cervical swab → nucleic acid amplification test (gold standard)

Treatment

  • Doxycycline
  • Pregnancy use erythromycin (doxycycline is contraindicated)
  • Partner must be contacted and tested/treated
Side note In pregnancy chlamydia infection is associated with preterm rupture of membranes. Risks to the baby include neonatal conjunctivites and pneumonia.

Complications

  • Pelvic Inflammatory Disease
  • Conjuctivitis
  • Fitz-Hugh-Curtis syndrome
  • Reiter’s syndrome (Reactive Arthritis)
  • Tubule infertility
  • Risk of ectopic pregnancy
Fitz-Hugh-Curtis syndrome is a rare complication of Pelvic inflammatory disease which involves liver capsule inflammation leading to the creation of adhesions.
Reiter’s syndrome also known as reactive arthritis presents with the classic triad: conjuctivities, urethritis and arthritis. (Can’t see, can’t pee, can’t climb a tree)

Gonorrhoea

Overview

  • Neisseria gonorrhoea
  • Bacteria – Gram -ve diplococcus
  • Second most common STI
  • Co-infection with chlamydia trachomatis

Clinical Presentation

  • Asymptomatic (majority)
  • Vaginal discharge
  • Low abdominal pain
  • Irregular menstrual bleeding
Characteristic of common cause of vaginal discharge
 Appearence  Smell Itch 
Physiological Clear/white, mucoid
Foreign body Grey or bloody, purulent Offensive
Malignancy Bloody, watery Offensive
Bacterial Vaginosis Grey, watery Offensive Itchy
Trichomonas Green, frothy Offensive  –
Candidasis Curd like (cheesy) Itchy
Gonococcal Green, watery  –

Diagnosis

  • Vaginal Swab/cervical swab → Gram Stain
    • Presence of pink “gram -ve” diplococcus
    • Presence of neutrophils
  • Vaginal Swab/cervical swab → Culture
    • Check for antibiotic syndrome
  • Vaginal Swab/cervical swab → nucleic acid amplification test
Remember Antibiotic-resistant Neisseria gonorrhoeae continues to be a significant public health concern.

Treatment

  • Ceftriaxone + azithromycin
  • Pregnancy same treatment
Side note In Pregnancy the risk of gonorrhoea infection to the baby is opthalmia neonatarum (50% of cases)

Complications

Bartholin’s abscess (cyst) The bartholin glands are located bilaterally at the base of the labia minora. Obstruction of the distal Bartholin’s duct may result in the retention of secretions, with resultant dilation of the duct and formation of a cyst. The cyst may become infected, and an abscess may develop in the gland. A Bartholin’s duct cyst does not necessarily have to be present before a gland abscess develops

Syphilis

Overview

  • Treponema pallidum
  • Bacteria – spiral looking (spirochete)

Clinical Presentation Syphilis can present in one of latent different stages

  • Primary
    • Occurs 1week-3 months post infection
    • Painless genital ulcers (chancre)
    • Inguinal lymphadenopathy
  • Secondary
    • Occurs within 2 years of infection
    • Fever
    • Polymorphic rash affecting palms, soles and everywhere else
    • Genital chondyloma lata
    • Lymphadenopathy
    • Anterior uveitits
  • Latent
    • no signs and sympoms before tertiary syphilis
  •  Tertiary (not contagious)
    • Occurs after 2 years of infection, but may take >40yrs to develop
    • Neurosyphilis
    • Cardiovascular syphilis
    • Gunmata (inflammatory plaques or nodules)
STDS with Ulcers
Chancroid (Painful)
Syphilis (Painless
Herpes (Painful)

Diagnosis

  • Treponemal enzyme immunoassay
  • Primary syphilis ulcer smear may show spirochaetes on dark feild microscopy

Treatment

  • Benzylpenicillin (1st line)
  • Erythromycin – If allergic to penicillin
  • Doxycycline – If allergic to penicillin (contraindicated in pregnancy)

Complications

Side Note In Pregnancy syphilis infection can result in preterm delivery, stillbirth, congenital syphilis and miscarriage

Bacterial Vaginosis

Overview

  • Mixed anaerobes: Gardnerella and Mycoplasma hominis which replace the usually dominant vaginal lactobacilli
  • Common cause of abnormal vaginal discharge in young women
  • NOT SEXUALLY TRANSMITTED
  • 12% of women will experience bacterial vaginosis at some point in their lives

Clinical Presentation

  • Asymptomatic (majority)
  • Smelly vaginal discharge “fishy”
Characteristic of common cause of vaginal discharge
 Appearence  Smell Itch 
Physiological Clear/white, mucoid
Foreign body Grey or bloody, purulent Offensive
Malignancy Bloody, watery Offensive
Bacterial Vaginosis Grey, watery Offensive Itchy
Trichomonas Green, frothy Offensive  –
Candidasis Curd like (cheesy) Itchy
Gonococcal  Green, watery  –

Diagnosis – Amsel criteria 3 out of 4 required

Amsel criteria
Homogenous whitish grey discharge
Vaginal pH >4.5 (5.5?)
Fishy smell of vaginal discharge
Presence of ‘clue cells’ on microscopy

Treatment

  • Metronidazole
  • Avoid vaginal douching/overwashing which can destroy natural vaginal flora

Complications

  • ↑Pelvic infection post surgery
Side Note In pregnancy bacterial vaginosis is associated with mid-trimester miscarriage, preterm rupture of membranes and preterm delivery

 

Candidiasis

Overview

  • Candidiasis is a fungal infection caused by yeasts that belong to the genus Candida
  • Candidiasis that develops in the mouth or throat is called “thrush” or oropharyngeal candidiasis
  • Candida albicans (90% )
  • Risk factors: immunosupressoin, antibiotics, pregnancy, diabetes mellitus and anaemia
  • Nearly 75% of all adult women have had at least one “yeast infection” in their lifetim

Clinical Presentation

  • Asymptomatic
  • Vulval itch or soreness
  • Thick, cur-like vaginal discharge
  • Dysuria
  • Classic white plaques on vaginal wall
Characteristic of common cause of vaginal discharge
 Appearence  Smell Itch 
Physiological Clear/white, mucoid
Foreign body Grey or bloody, purulent Offensive
Malignancy Bloody, watery Offensive
Bacterial Vaginosis Grey, watery Offensive Itchy
Trichomonas Green, frothy Offensive  –
Candidasis Curd like (cheesy) Itchy
Gonococcal  Green, watery  –

Diagnosis

  • Characteristic appearance
    • Vulval and vaginal aerythema
    • Vulval fissuring
    • White plaques on vaginal wall
  • Microscopic – wet slide show spores and pseudohyphae

Treatment

  • Only treat if asymptomatic
  • Azoles +/- topical azoles
Pharmacology Azole inhibit fungal inhibitis enzymes responsible for the synthesis  of ergosterol. Ergosterol is an essential component of the fungal cell membrane, inhibition of its synthesis results in increased cellular permeability causing leakage of cellular contents. Side effects: symptoms of overdose include hallucinations and paranoid behavior.

Complications

  • Not significant

Herpes Simplex

Overview

  • Herpes Simplex Virus type 1 and type 2
    • HSV-1 cause oral and genital ulcers
    • HSV-2 cause genital ulcers only
  • Both HSV-1 and HSV-2 are chronic and lifelong infections
  • HSV-1 is mainly transmitted by oral-to-oral contact to cause oral herpes (which can include symptoms known as “cold sores”), but can also cause genital herpes.
  • Symptoms of herpes include painful blisters or ulcers at the site of infection.
  • Herpes infections are most contagious when symptoms are present but can still be transmitted to others in the absence of symptoms.

Clinical Presentation

  • Similar for HSV-1 and HSV-2 infections.
  • Patients will often experience prodromal symptoms
    • Tingling
    • Itching
    • Paresthesias
    • Pain from an hour to a day before the outbreak
  • Flu-like symptoms +/- inguinal lymphadenopathy
  • Ulcers develop – lesions typically heal within 5 to 10 days.
  • Patients with HSV-1 infections typically have fewer outbreaks than patients with HSV-2 infections.

Diagnosis

  • Presence of classic herpes rash
  • PCR testing of vesicular fluid
  • Culture of vesicular fluid

Treatment

  • Not cure for gential herpes
  • Symptomatic relief – analgesia, topical anaesthetic
  • Oral aciclovir
  • Topical aciclovir
  • Condoms or abstinence whilst prodromal or sympatomatic → ↓transmission
Pharmacology Aciclovir is an antiviral drug that acts as an antimetabolite, inhibits DNA synthesis by acting as a chain terminator. Aciclovir is used for the treatment of herpes simplex virus infections, varicella zoster (chickenpox) and herpes zoster (shingles). Side effects: Nephrotoxicity and neurotoxicity, which usually resolve after cessation of aciclovir therapy.

Complications 

  • Meningitis
  • Encephalitis
  • Keratitis
  • Sacral radiculopathy
  • Transverse melitis
  • Depression – with stigma
Side Note In pregnancy herpes infection can lead to neonatal herpes a rare, but sometimes fatal, condition that can occur when an infant is exposed to HSV in the genital tract during delivery.

Human Papillomavirus

Overview 

  • HPV is the most common sexually transmitted infection
  • Many types of HPV
  • Responsible for cervical cancer and genital warts
    • HPV types 6 and 11 cause 90% of genital warts (Condyloma accuminatum)
    • HPV types 16 and 18 cause 70% of cervical cancers

Clinical Presentation – condyloma accuminatum

  • Asymptomatic (majority)
  • Painless genital lumps
  • Perianal warts (no association with anal intercourse)

Diagnosis

  • Clinical appearence
  • Pap smear

Treatment for genital warts

  • Clinic Treatment – Ablation
    • Cryotherapy
    • Trichloroacetic acid
    • Laser
  • Home treatment (contraindicated in Pregnancy)
    • Podophyllotoxin cream
    • Imiquimod cream

Complications

  • HPV types 6 and 11 cause 90% of genital warts
  • HPV types 16 and 18 associated with high-grade CIN and cause 70% of cervical cancers

References

Drugbank.ca
CDC
Oxford Handbook of Obstetrics and Gyaenacology