Sexually Transmitted Infections Flashcards
What is Bacterial vaginosis and is it an STI?
Definition – overgrowth of bacteria in the vagina commonly Gardnerella Vaginalis resulting in reduction in lactobacilli.
Note – not an STI
Often confused with a Trichomonas infection
What are the risk factors for bacterial vaginosis?
Multiple sexual partners Presence of an STI Cleaning products Antibiotics IUD Black women Smoking
How does bacterial vaginosis typically present?
Asymptomatic Fishy offensive smell Watery grey discharge More noticeable after intercourse Itchy and irritated Dysuria
pH > 4.5
How should suspected bacterial vaginosis be investigated/tested for?
Rule out trichomonas
Swab and culture – clue cells = vaginal epithelial cells studded with gram variable coccobacilli
Litmus test
Amsel’s criteria for diagnosis of bacterial vaginosis - 3 of the following 4 points should be present:
• thin, white homogenous discharge
• clue cells on microscopy: stippled vaginal epithelial cells
• vaginal pH > 4.5
• positive whiff test (addition of potassium hydroxide results in fishy odour)
How is bacterial vaginosis managed?
Asymptomatic doesn’t require treatment
Oral metronidazole for 7 days or single dose of 2g or topical metronidazole for 5 days
(note metronidazole has the same effect as disulfiram when you drink alcohol)
Clindamycin or Tinidazole
What does a full STI screen for a women involve?
Chlamydia – Vulvovaginal swab (first choice) or endocervical swab – NAAT. If indicated rectal, throat or eye swabs
Gonorrhoea – Vulvovaginal swab for NAAT, endocervical for NAAT or microscopy and culture. If indicated rectal, throat or eye swabs
Syphilis – blood test ELISA, TPPA and RPR
Trichomonas – high vaginal swab under posterior fornix
What does a full STI screen for a man involve?
Chlamydia – first catch urine sample or urethral swab – NAAT. If indicated rectal, throat or eye swabs
Gonorrhoea – first pass urine for NAAT, urethral/meatal swab for NAAT or microscopy and culture. If indicated rectal, throat or eye swabs
Syphilis – blood test ELISA, TPPA and RPR
Trichomonas – urethral swab or first pass urine sample
What are the two types of genital herpes?
HSV type 1 – 70% of genital herpes and has lower recurrence compared to type 2 + orofacial also causing cold sores.
HSV type 2 – exclusively found in the genitals. High recurrence rate in 1st year
Both are DNA viruses
Can also have reactivation of Varicella Zoster from childhood chicken pox
How does genital herpes present?
Genital or anal soreness and uritcaria Genital discharge Fever and myalgia Dysuria Headaches Local rash and sores Incubation period of 3-14 days. Time until first symptoms can be years
What do the primary lesions from genital herpes look like?
Primary lesions – look like blisters
Asymptomatic shedding and so spreading can occur meaning people transmit even though they are unaware of their infection
How do recurrent outbreak of herpes present and what can trigger an outbreak?
Recurrent outbreaks often shorter and milder. Usually burning and itching around the genitals with painful red blisters. Triggers for the outbreak can be: immunodeficiency, stress, sexual intercourse and menstruation.
How should suspected herpes be investigated?
Swab open lesions and PCR – sensitive by type specific
Full STD screen
How should genital herpes be managed?
Rest and analgesia – 5% lidocaine ointment
Saline washing and Vaseline
Avoid sexual contact when symptomatic and disclose to partners
Antivirals for 5 days only if symptomatic as it does not cure however, don’t wait for test results before initiating treatment
Aciclovir 3 or 5 times daily
If aciclovir unsuccessful it is unlikely others will as they are all derivatives that break down into it aciclovir
Very frequent outbreaks can be treated with suppressive treatment = daily aciclovir
What complications can occur from untreated herpes outbreaks?
Urinary retention and adhesions
Meningism (HSV meningitis is very rare)
Recurrences
What organism causes a chlamydia infection?
Multiple serotypes, full name Chlamydia Trachomatis
Gram positive intracellular bacterium
How is chlamydia transmitted?
Sexually transmitted but doesn’t necessarily have to be penetrative, can simply be skin to skin contact. Is possible for it to cause conjunctivitis from semen/vaginal fluid in the eye or from infected mother to baby
Can also infect the anal region and the pharynx
How does a chlamydia infection present in women?
Incubation period between 7 and 21 days
Most commonly asymptomatic
Women Dysuria Abnormal vaginal discharge Intermenstrual or postcoital bleeding Deep dyspareunia Lower abdominal pain Cervicitis and contact bleeding Mucopurulent endocervical discharge Pelvic tenderness Cervical excitation
How does a chlamydia infection present in men?
Incubation period between 7 and 21 days
Most commonly asymptomatic
Urethritis causing dysuria and urethral discharge
Epididymo-orhcitis causing testicular pain
Epididymal tenderness
Mucopurulent discharge
What investigations should be done when you suspect chlamydia?
Full STI screen
Women – Vulvovaginal swab (first choice) or endocervical swab.
Men – First catch urine sample or urethral swab.
If indicated rectal, throat or eye swabs for men or women
Sent for NAAT test
Contact Tracing
Dual testing with Gonorrhoea important
Differentiate between Gonorrhoea and Chlamydia instantly with a gram stain
How is Chlamydia treated?
Doxycycline 100mg PO BD for 7 days
Azithromycin 1g PO
Erythromycin 500mg BD for 14 days
Ofloxacin 200mg BD or 400mg OD for seven days
Safe sex practices
What complications can occur due to chlamydia infections?
PID in women
Epididymo-orchitis which is painful and can lead to infertility
Sexually acquired reactive arthritis
What causes gonorrhoea infections?
Gram negative diplococcus bacteria Neisseria Gonorrhoea
