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
How is gonorrhoea transmitted?
Sexually transmitted via vaginal, anal or oral sex
Vertically transmitted causing conjunctivitis
How does gonorrhoea infection present in a woman?
Often asymptomatic
Usually develop symptoms 2-5 days following infection
Women Altered/increased vaginal discharge (thin watery, green or yellow) Dysuria Dyspareunia Lower abdominal pain Intermenstrual or post coital bleeding (rare) Mucopurulent endocervical discharge Cervicitis and contact bleeding Pelvic tenderness
How does gonorrhoea infection present in a man?
Often asymptomatic
Usually develop symptoms 2-5 days following infection
Mucopurulent urethral discharge
Dysuria
Epididymal tenderness
Rectal – usually asymptomatic, anal discharge or anal pain/discomfort
Pharyngeal infection – asymptomatic 90% of the time
How should suspected gonorrhoea be investigated?
Full STI screen
Women – Vulvovaginal swab for NAAT, endocervical for NAAT or microscopy and culture
Men – first pass urine for NAAT, urethral/meatal swab for NAAT or microscopy and culture
Swabs for NAAT from throat, rectum or eye if indicated
If NAAT positive culture for sensitivity
Dual testing for chlamydia important
Differentiate between Gonorrhoea and Chlamydia instantly with a gram stain
Contact tracing
How is gonorrhoea managed?
Treated empirically until culture returns and then target antibiotics if infection still present
Single dose of 1g ceftriaxone IM
Cefixime 400mg PO stat plus azithromycin 1g PO only if IM injection contraindicated or rejected. If allergic to penicillin or cephalosporins discuss with GUM
Safe sex practices
What are the potential complications of Gonorrhoea infections
PID
Epididymo-orhcitis
Prostatitis
Disseminated gonococcal infection – joint pain and skin lesions – rare
What is Syphilis?
STI caused by spirochete gram negative bacterium – Treponema pallidum
How is syphilis transmitted?
Sexually transmitted – motile bacterium enters through breaks in the skin
Vertical transmission via placenta (congenital syphilis)
Describe the disease progression of syphilis
Bacteria divide forming an infectious hard ulcer called a chancre after incubation period of about 2-3 weeks this is called primary syphilis.
Secondary syphilis follows that with symptoms and then it enters a latent phase, from here it is non-infectious.
If left it can persist and cause systemic damage via obliterating arteritis – endothelial cells excessively proliferate eventually blocking the lumen of the vessel.
Describe the clinical presentation of primary syphilis?
Primary syphilis
Papule forms that ulcerates into a chancre which are painless. Usually singular, hard and non-itchy. These classically heal in 3-10 weeks.
Describe the clinical presentation of secondary syphilis?
Secondary syphilis
Develops 3 months post infection. Features include: skin rash (hands and soles – non itchy or painful), fever, malaise, arthralgia, weight loss, headaches, condylomata lata (elevated plaques like warts in moist areas of the body), painless lymphadenopathy and silvery grey mucus membrane lesions.
Describe the clinical presentation of tertiary syphilis?
Tertiary syphilis
Presents many years later and is categorised into:
• Gummatous syphilis – forms in bone, skin and mucous membranes of the upper respiratory tract, mouth and viscera or connective tissue e.g. lung, liver and testis.
• Neuro syphilis – Tabes dorsalis (ataxia, numbness, loss of pain, temperature and reflexes and lightning pains), Dementia, Meningovascular complications (cranial nerves, strokes and cerebral gummas) and Argyll Robertson pupil – constricted and unreactive to light but accommodates.
• Cardiovascular syphilis – aortic regurgitation and aortic root dilation, angina due to stenosis in coronary arteries and dilation and calcification of the ascending aorta
How should suspected syphilis be investigated?
Dark ground microscopy of the chanchre fluid
PCR testing of swab from active lesion
Antibody tests: Treponemal ELISA (IgG/IgM) +ve for life,
TPPA or TPHA +ve for life
Non Treponemal tests, RPR/VDRL – rises in early disease, negative after treatment
Lumbar punctures – CSF antibody test in neurosyphilis
How should syphilis be managed at different stages of the disease?
Early syphilis – Benzathine penicillin – 2.4 MU IM single dose
Late Syphilis – Benzathine penicillin – 2.4 MU IM 3 doses at weekly intervals
Neurosyphilis – Procaine penicillin 1.8 MU 2.4 MU IM OD plus probenecid 500mg PO QDS for 14 days OR Benzylpenicillin 10.8-14.4g daily given IV in 4 hourly doses for 14 days
Also
Full STI screen Patient education regarding safe sex Abstinence until cured Contact tracing Follow-up serology to determine response to treatment
What is PID?
The result of infection ascending from the endocervix, causing endometritis, salpingitis, parametritis, oophoritis, tubo-ovarian abscess and/or pelvic peritonitis.
Most common between ages 20-30
What are the risk factors for developing PID?
Young age (15-24) Recent partner change Lack of use of barrier contraception Multiple sexual partners Low socioeconomic class IUCD
What are the common causes of PID?
Often polymicrobial
Most commonly due to chlamydia trachomatis or Neisseria Gonorrhoea
Also, can be due to Gardnerella vaginalis, mycoplasma genitalium or hominis
Describe how PID presents?
Pyrexia, pain in lower abdomen iliac fossa area Deep dyspareunia and PCB Abnormal bleeding Abnormal discharge Dysuria History of STI Fever Cervical excitation (pain on examination) Purulent cervical discharge
What differetial diagnoses are important to rule out before diagnosing PID?
Ectopic pregnancy, ruptured ovarian cyst, endometriosis or urinary tract infection.
How should PID be investigated?
Urine dip and pregnancy test Endocervical and high vaginal spear STI screen TV USS Laparoscopy Contact tracing
How is PID managed?
Start treatment whilst awaiting swab results
Ceftriaxone IM STAT, Metronidazole and Doxycycline for 14 days
Symptomatic management of pain
Avoiding sexual intercourse
Contact tracing – nausea, vomiting and high fever
When should a PID patient be admitted to hospital?
Admit to Hospital if: Pregnant or risk of ectopic pregnancy Severe symptoms Signs of pelvic peritonitis Treatment failure Requires emergency surgery
What potential complications can occur form PID?
Tubo ovarian abscess Higher risk of ectopic pregnancy Infertility Chronic pelvic pain Fitz-Hugh-Curtis Syndrome – RUQ pain and peri-hepatitis following Chlamydial PID
What causes thrush?
Overgrowth of candida Albicans, a normal vaginal commensal
What are the risk factors for developing a thrush infection?
Cleaning products Use of antibiotics Oral contraceptives Steroids Pregnancy Obesity Diabetes Immunosuppression – HIV
Describe the clinical features of vaginal thrush infections
White curd like discharge that is odourless Itchy and irritated vulva Erythematous Dysuria Superficial dyspareunia
pH < 4.5
How should a suspected thrush infection be investigated?
Rule out differential diagnoses of bacterial vaginosis, trichomonas vaginalis and UTI.
Check for diabetes
If uncomplicated then no investigations required
Swab
Litmus test for pH
How should an acute thrush infection be managed?
Intravaginal antifungal – clotrimazole or fenticonazole
Oral antifungals – fluconazole or itraconazole (single doses)
Topical imidazole cream – can be given as an adjunct
How should chronic thrush infections be managed?
If recurrent or treatment failure
Consider alternative diagnosis
Consider predisposing factors and treat them
Check concordance with medication
Consider use of induction-maintenance regime with daily treatment for a week followed by maintenance treatment weekly for 6 months.
What is Trichomonas Vaginalis
Anaerobic flagellated protozoan parasite infecting the vagina. Passes on exclusively as an STI.
What are the risk factors for developing Trichomonas vaginalis infections?
Multiple sexual partners
Unprotected sexual intercourse
A history of other STIs
Older woman
What are the clinical features of Trichomonas Vaginalis infection in females?
Female pH > 4.5 Yellow/Green frothy discharge that is fishy and offensive odour Pruritis Vaginitis Dyspareunia Dysuria Strawberry cervix
What are the clinical features of Trichomonas Vaginalis infection in males?
Male Urethral discharge Dysuria and frequency Pain and pruritis around the foreskin Inflammation of the gland penis – balanoposthitis
How should suspected trichomonas vaginalis infections be investigated?
Female
High vaginal swab from the posterior fornix
Self-administered vaginal swab
Full STI screen
Males
Urethral swab or first void urine sample
Full STI screen
How are trichomonas Vaginalis infections managed?
Metronidazole BD for 5 days or large STAT dose 2.5g (avoid in pregnancy or breast feeding)
Treat partner simultaneously or contact tracing
Alternatives
Tinidazole
Abstain from intercourse whilst taking treatment
