Sexually Transmitted Diseases Flashcards
Cause of chlamydia
Caused by bacterium Chlamydia trachomatis
Types of chlamydia
Serotypes A-C - causes ocular infection
Serotypes D-K - responsible for GI infection
Serotypes L1-L3 - causes lymphogranuloma venereum
Pathophysiology of chlamydia
Transmission via unprotected vaginal, anal or oral sex
Enters host cell as an elementary body - infectious form
- becomes reticular body - non-infectious
- mature back to elementary body
Risk factors for chlamydia
Age <25 Sexual partner positive for chlamydia Recent change in sexual partner Co-infection with another STI Non-barrier contraception or lack of consistent use of barrier contraception
Clinical features of chlamydia in women
Symptoms - Dysuria - Abnormal vaginal discharge - Intermenstrual or postcoital bleeding - Deep dyspareunia - Lower abdominal pain Signs - cervicitis +/- contact bleeding - Mucopurulent endocervical discharge - Pelvic tenderness - Cervical excitation
Chlamydia clinical features in men
Symptoms
- urethritis
- dysuria
- urethral discharge
- epididymo-orchitis
- testicular pain
Signs
- epididymal tenderness
-mucopurulent dischargeInvestigations for chlamydia
Tests available at sexual health clinics, GUM clinics and GPs
National screening programme for under 25s
Nucleic acid amplification test
- women = vulvovaginal swab
- men = first catch urine sample
Management of chlamydia
Doxycycline 100mg twice daily for 7 days or
Azithromycin 1g single dose
Avoid sexual intercourse/oral sex until completed treatment/7days following azithromycin
Complications of chlamydia
Reactive arthritis
Women
- salpingitis/endometritis -> PID
-> perihepatitis, ectopic pregnancy and infertility
Men
- epididymitis/epididymo-orchitis -> infertility
Complications of chlamydia in pregnancy
Increase risk of premature delivery with low birth weight
Increased risk of miscarriage/stillbirth
Neonatal chlamydial conjunctivitis and pneumonia
Treat with erythromycin
Causes of genital herpes
Herpes simplex virus
Transmitted via skin-to-skin contact
Types of genital herpes
HSV-1
- genital herpes
- affects areas around mouth and nose causing cold sores
HSV-2
- genital and anal areas causing genital herpes
Pathophysiology of genital herpes
HSV enters body through small cracks in skin or mucous membranes
Virus travels to nearest nerve ganglion and remains there
During reactivation virus travels back down nerve into surface of genitals causing symptomatic outbreak
Risk factors of genital herpes
Having multiple sexual partners
Oral sex with partner suffering from cold sores
Clinical features of primary infection of genital herpes
Small red blisters around the genitals that are very painful and can form open sores
- In males - on the penis, anus, buttocks and thigh
- In females - on the vulva, clitoris, buttocks and anus
Vaginal or penile discharge
Flu-like symptoms, fever, muscle aches
Itchy genitals
Lesions crust and heal after about 20 days
Clinical features of secondary infection of genital herpes
Often shorter and less severe
Burning and itching around the genitals
Painful red blisters around the genitals
Clinical features of cold sores
Painful lesions around the mouth and nose
- last 7-10 days
Investigations for genital herpes
History - sexual partners, cold sores, STIs
Swab from open sore
- tested for presence of HSV
- PCR can differentiate between 1 and 2
Management of genital herpes
Primary infection - aciclovir Recurrent outbreaks - painkillers - petroleum jelly - ice packs - episodic treatment with aciclovir - daily aciclovir if severe to supress
Herpes during pregnancy
If contracted before pregnancy - will have antibodies so baby safe - vaginal or C-section If contracted during last trimester - no antibodies so baby at greater risk - C-section recommended
Define genital warts
Benign epithelial or mucosal outgrowths cause by DNA human papilloma virus (HPV)
Pathophysiology of genital warts
Most commonly HPV6 and HPV11
Spread through skin-to-skin contact
Virus penetrates epithelial barrier and infects basal keratinocytes
- virus replicates -> multiplication of keratinocyte
Types of oncogenic HPV
HPV16 and HPV 18
- lead to cancer of vulva, vagina, cervix and anus
Risk factors for genital warts
Early age at first sexual intercourse Multiple sexual partners Immunosuppression Smoking Diabetes associated with persistence of warts
Clinical features of genital warts
Warts appear after initial infection
- painless, fleshy growths
Investigations for genital warts
Diagnosis by examination
Biopsy for atypical lesions and suspected intraepithelial neoplastic lesions
Management of genital warts
Lesions most likely resolve spontaneously
Topical treatments
- podophyllotoxin - small clusters, non-keratinised lesions
- imiquimod - larger keratinised warts
Physical ablation
- excision - pedunculated/large warts or accessible small hard warts
- cryotherapy - multiple small warts
- electrosurgery - large warts that have failed to respond to topical treatments
- laser surgery - difficult to access warts eg in anus
Features of HPV vaccination
Protects mainly against HPV16 and HPV18
- since 2012 protected against HPV 6 and 11
Offered to girls aged 12-13 in UK
Features of HPBV in pregnancy
Due to hormonal changes genital warts may multiply or enlarge
Treatment aims to reduce lesions so neonate’s exposure reduced
Define HIV
Human Immunodeficiency Virus
- single stranded RNA retrovirus that infects and replicates within human immune system using CD4 host cells
Leads to AIDS (Acquired Immune Deficiency Syndrome)
Pathophysiology of HIV
Infects and replicates within CD4 cells
- single stranded RNA converted to DNA by reverse transcriptase
- combined with host DNA by integrase
When infected cell divides viral DNA read creating viral protein chains
- immature virus pushes out of cell retaining some cell membrane
- virus matures when protease cuts viral protein chains
CD4 levels in HIV infection
Seroconversion - production of anti-HIV antibodies during primary infection
- flu-like symptoms
- CD4 levels fall
Latent phase
- initially asymptomatic
- CD4 levels fall and viral load increases
Transmission of HIV
Unprotected sexual contact
Sharing of injecting equipment
Medical procedure - blood products, skin graft, organ donor, artificial insemination
Vertical transmission - mother to child in utero, during childbirth or breastfeeding
At risk groups in UK for HIV
Men who have sex with men
Intravenous drug users
Those in high prevalence areas
Those who have had unprotected sex with a partner who has lived or travelled in Africa
Define PID
Infection of upper genital tract in females
- affects uterus, fallopian tubes and ovaries
Pathophysiology of PID
Infective inflammation
- spread of bacterial infection from vagina or cervix to upper genital tract
- Chlamydia trachomatis
- Neisseria gonorrhoea
Risk factors for PID
Sexually active
Aged under 15-24
Recent partner change
Intercourse without barrier contraceptive protection
History of STIs
Personal history of pelvic inflammatory disease
Instrumentation of cervix
- inadvertently introduces bacteria
- gynae surgery, TOP, insertion of IUD/IUS
Clinical features of PID
Can be asymptomatic
Lower abdominal pain
Deep dyspareunia (painful sexual intercourse)
Menstrual abnormalities (e.g menorrhagia, dysmenorrhoea or intermenstrual bleeding)
Post-coital bleeding
Dysuria (painful urination)
Abnormal vaginal discharge (especially if purulent or with an unpleasant odour)
Differential discharge of PID
Ectopic pregnancy (a pregnancy test is mandatory to exclude this). Ruptured ovarian cyst Endometriosis Urinary tract infection
Investigations for PID
Endocervical swabs
- for gonorrhoea and chlamydia
Full STI screen – HIV, syphilis, gonorrhoea and Chlamydia
Urine dipstick +/- MSU – to exclude UTI
Pregnancy test - exclude pregnancy
TV USS – if there is severe disease or diagnostic uncertainty
Laparoscopy - severe cases of diagnostic uncertainty for biopsy
Management of PID
14 day broad spectrum abx - ceftriaxone - doxycycline - metronidazole Avoid sexual intercourse All sexual partners from last 6 months should be tested
Reasons for admittance to hospital for PID
f pregnant and especially if there is a risk of ectopic pregnancy
Severe symptoms: nausea, vomiting, high fever
Signs of pelvic peritonitis
Unresponsive to oral antibiotics, need for IV therapy
Need for emergency surgery or suspicion of alternative diagnosis
Complications of PID
Ectopic pregnancy – due to narrowing and scarring of the fallopian tubes
Infertility – affects 1 in 10 women with PID
Tubo-ovarian abscess
Chronic pelvic pain
Fitz-Hugh Curtis syndrome – perihepatitis that typically causes right upper quadrant pain
Define syphilis
STI caused by spirochete gram negative bacteria
- Treponema pallidum subspecies pallidum
Pathophysiology of syphilis
Contracted by sexual intercourse, mother to foetus via placenta and through infected blood products
Treponema pallidum enters, divides and infectious hard ulcer forms at site of contact after incubation period = primary syphilis
If untreated can cause systemic damage by obliterating arteritis
- endothelial cells excessively proliferate
Risk factors for syphilis
Engaging in unprotected sex – especially with high risk partners
Multiple sexual partners
Men who have sex with men (MSM)
HIV infection
Clinical features of primary syphilis
Papule appears before ulcerating into a chancre
- painless ulcer
- singular, hard and non-itch
- heals within 3-10 weeks
Clinical features of secondary syphilis
Usually develops 3 months post-infection
- Skin rash – hands and soles of the feet (not usually itchy or painful)
- Fever
- Malaise
- Arthralgia
- Weight loss
- Headaches
- Condylomata lata - elevated plaques like warts at moist areas of skin
- Painless lymphadenopathy
- Silvery-grey mucous membrane lesions – oral, pharyngeal, genital
Disease then enters asymptomatic latent phase
Clinical features of tertiary syphilis
Presents may years after initial infection
Gummatous syphilis
- form in bone, skin, mucous membranes of the upper respiratory tract, mouth and viscera or connective tissue
- patients non-infectious
Neurosyphilis
- Tabes dorsalis – ataxia, numb legs, absence of deep tendon reflexes, lightning pains, loss of pain and temperature sensation, skin and joint damage
- Dementia – cognitive impairment, mood alterations, psychosis
- Meningovascular complications – cranial nerve palsies, stroke, cerebral gummas
- Argyll Robertson pupil – pupil is constricted and unreactive to light, but reacts to accommodation
Cardiovascular syphilis
- Aortic regurgitation due to aortic valvulitis (diastolic murmur), also aortic root dilatation
- Angina due to stenosis of the coronary ostia
- Dilation and calcification of the ascending aorta
Investigations for syphilis
Dark ground microscopy of chancre fluid - detects spirochaete in primary syphilis
PCR testing of swab from active lesion
Serology:
- Treponemal tests – assess for exposure to treponemes
- Treponemal ELISA (IgG/IgM) – remains positive for life
- TPPA or TPHA – remain positive for life
- Non-treponemal tests:
- RPR/VDRL: rises in early disease; falling titres indicate successful treatment or progression to late disease - False positives can occur in inflammatory conditions or during pregnancy
Lumbar puncture: CSF antibody tests in neurosyphilis
Management of syphilis
Penicillin
Advising patients to avoid sexual contact of any kind, or exposure of other people to active lesions until the condition has been successfully treated
Screening for other STIs
Patient education
Contact tracing
Follow-up serology to determine response to treatment
Syphilis in pregnancy
Screening offered as part of antenatal screening
T. pallidum has potential to cross placenta or infect baby during delivery
If left untreated, syphilis during pregnancy may result in miscarriage, stillbirth, pre-term labour or congenital syphilis
- severe and debilitating
- saddle nose, rashes, fever and failure to gain weight
Define trichomoniasis
Curable STI caused by protozoan trichomonas vaginalis
Pathophysiology of trichomoniasis
Transmitted through unprotected vaginal intercourse
Affects the female urethra, vagina and paraurethral glands and the male urethra and underneath the foreskin
Replicates via binary fission destroys epithelial cells through direct cell contact and by the release of cytotoxins
Risk factors for trichomoniasis
Multiple sexual partners
Unprotected sexual intercourse
A history of other STIs
Older women are more at risk of TV
Female features of trichomoniasis
Symptoms
- Offensive vaginal odour
- Abnormal vaginal discharge – thick/thin/frothy and yellow-green
- Itchiness or soreness of the vulva
- Dyspareunia
- Dysuria
Signs
- Abnormal vaginal discharge – thick/thin/frothy and yellow-green
- Vulvitis
- Vaginitis
- Strawberry cervix – punctate and papilliform appearance
Male features of trichomoniasis
Symptoms - Urethral discharge - Dysuria - Urinary frequency - Pain or itching around the foreskin Signs - Urethral discharge - Balanoposthitis – inflammation of the glans penis (rare)
Investigations for trichomoniasis
Female: - High vaginal swab is taken from the posterior fornix during examination - Self-administered vaginal swab Males - Urethral swab - First void urine sample
Management of trichomoniasis
Metronidazole
Contact tracing - patient’s current partner(s) and any sexual partners of the preceding four weeks should also be tested and treated simultaneously
Abstain from sexual intercourse whilst being treated
Trichomonas vaginalis in pregnancy
May carry risk of premature labour and low-birth weight
Infection at delivery may predispose to maternal postpartum sepsis
