Sexually transmitted disease Flashcards
HIV
Single stranded RNA retrovirus that infects and replicates within the human immune system using host CD4 cells
HIV pathophysiology
Single stranded RNA retrovirus that infects and replicates with CD4 cells
Penetrates the host CD4 cell & empties its contents
Infected cell divides, viral DNA is read, creating viral protein chains & immature viruses pushes out of the cell, retaining some cell membrane
Host cell destroyed in process
HIV CD4 levels
Upon seroconversion (the process of producing anti-HIv antibodies during primary infection), flu-like sx experienced
CD4 levels fall → person is extremely infectious
Over next months to years → infection can enter a latent phase → more susceptible to infections
HIV transmission
Unprotected sexual contact
Sharing of injecting equipment
Medical procedures
Vertical transmission
HIV risk factors
MSM
IV drug users
High prevalence areas
Unprotected sex with a partner who has lived/travelled in Africa
HIV clinical features
Seroconversion illness - non-specific, flu-like illness → fever, muscle aches, malaise, lymphadenopathy, maculopapular rash, pharyngitis
Symptomatic HIV - weight loss, high temperatures, diarrhoea, frequent minor opportunistic infections e.g. HZV or candidiasis
HIV ix
4th generation combo essay (EIA) - detect anti-HIV antibodies
Confirmatory tests in lab if positive - immunoblot
RNA detection by PCR for ‘viral load’ → better in earlier disease
Second sample to confirm patient ID
HIV+ = CD4 count, HIV viral load, HIV resistance testing, baseline bloods, screening for other relevant infections
HIV mx
HAART: highly active antiretroviral therapy
2 NRTI + 3rd agent
- integrase inhibitor
- protease inhibitor
Compliance key and patient must keep taking the drugs for the rest of their lives
Most patients stable & monitored 6-12 monthly
HIV monitoring
Regular tests:
- CD4 count
- HIV viral load
- FBC
- U&Es
- Urinalysis
- ALT, AST & bilirubin
Pregnancy testing & in treatment failure → resistance testing
HIV prevention
Safe sex, condom use
Screening & regular testing
Treatment as prevention
Post-exposure prophylaxis → within 72 hours of high-risk exposure, available via A+E/sexual health service, truvada + raltegravir
Pre-exposure prophylaxis → at risk patients eligible, truvada/descovy daily or ‘event-based’
Hep B transmission
Parenteral
Vertical
Sexual - multiple partners, condom less AI, rimming
Sporadic - prisons, LD institutions
Hep B prevention
Testing - high risk groups
Vaccinations - high risk groups
Advice to patient living with HBV - inform GP/dentist, don’t donate, cover wounds
Pregnancy & HBV - vaccinate neonate
Sexual contacts - vaccination, condoms/dental dams
Household contacts - vaccination
Hep B investigations
Surface antigen - does pt have hep B? → active hep B
Core antibody - has pt ever been exposed?
Surface antibody - is pt immune to hep B?
Hep B viral load
Hep B mx
Notifiable
Hepatology referral
Screen for other infections
Treatment options inc. peg interferon alpha 2a, antivirals (entecavir, tenofovir)
Post-exposure prophylaxis in BBI
HIV PEP - starter packs of ARVs, duration of 28 days
Hep B - booster, HBIG
Hep C - no prophylaxis available
Hep B needlestick injury
Source patient - not affected staff member
Recipient - blood samples, further testing at 6, 12 & 24 weeks
While waiting - safe sex, good infection control, avoid blood donation
Hep B complications
Acute liver failure
Mortality
Increased risk of pregnancy cx
Chronic hep B
Hep C transmission
Parenteral - needlestick, transfusion, haemodialysis
Vertical
Sexual transmission - low
Hep C clinical features
Asymptomatic
Acute icteric hepatitis, chronic hepatitis picture
Incubation period ~6 weeks
70% untreated progress to chronic infection → cirrhosis & HCC
Hep C testing
Anti-HCV (total) for initial screening - current or past infection
- positive 4-10 weeks after exposure
- antibody provides incomplete protection - reinfection possible
HCV RNA - distinguish current from past infection
Hep C genotype - guide treatment
Hep C prevention
Risk modification
No vaccine
No immunoglobulin
No PEP
Testing can reduce the risk of transmission to others
Hep C advice
Curable
Check for other hepatitis infections
Do not donate blood, semen or organs
Screen for STIs
Acute hepatitis is notifiable
Hep C mx
Refer to hepatology
Direct acting antivirals - 8-12 weeks
- often used in combination
- prevent virus from completing life-cycle
Genital sores aetiology
Infectious
- viral - HSV, varicella, CMV, EBV, mpox
- bacterial - syph, strep, staph
- fungal
Inflammatory/immune
Drug related
Malignancy
Genital sores hx
Hx of PC
Associated symptoms - genital, systemic, rashes, eyes, mouth, joints
Happened before?
DHx, PMHx, DHx, allergies
Sexual hx, contraception, pregnancy risk
Mpox
Zoonotic viral infection → mostly west and central Africa
- SymptomsSystemic features precede rashRash 1-5 days later → widespread/local, contagious until scabs fall over with healed skin below
Vaccination for high risk groups in future
Mx - self-limiting, tecovirimat for severe presentations
Genital sores differentials
LGV (MSM) - invasive chlamydia, primary lesion = ulcer
- untreated → secondary disease (LN, lymphadenitis) , tertiary disease (chronic inflammation & destruction)
Tropical ulcer disease
Non sexually acquired genital ulceration - often adolescents, supportive treatment, associated with EBV
Behcet’s
Fixed drug eruption
Erosive lichen planus
Malignancy - chronic, non-healing ulceration
- RFs = smoking, previous HPV linked malignancy, lichen sclerosus
Genital HSV presentations
Primary - first infection with no pre-existing antibodies
Non-primary - first infection with pre-existing antibodies
Recurrent episodes - recurrence of clinical symptoms due to reactivation of pre-existent infection
Genital HSV ix
Immediate - HSV PCR from base of lesion
Delayed - full STI screen, syphilis serology, HIV antibody test
HSV serology (helpful only in specific situations) - serum samples weeks apart can show seroconversion, pregnancy
Genital HSV mx
Course of oral antiviral
5% lidocaine - pain relief
Rest and analgesia
Salt water bathing
Vaseline
Avoid sexual contact whilst symptomatic, disclose to partner
Genital HSV complications
Superinfection
Urinary retention
Proctitis
Emotional distress
HSV in pregnancy
Recurrent episode - low rise
Primary infection in last trimester - risky for newborn
- neonatal HSV has high rates of morbidity
Syphilis aetiology
Treponema pallidum
Syphilis transmission route
Sexually - including OI
Vertical
Syphilis stages
Primary (chancre) - ulcer around genitals, anus, oral mucosa
Secondary - maculopapular rash all over body, mucous patches in mouth, early neurological involvement
Latent - no symptoms after period of primary & secondary stages
Tertiary - late neuro, CVS complications
Syphilis ix
Lesion - treponemal PCR
Bloods - Treponemal enzyme immunoassay
If initial test is positive - TPPA, RPR
Full STI screen inc. HIV testing
Syphilis mx
Depends on the stage
First line - IM benzathine penicillin
Alternatives - doxy, ceftriaxone
Genital warts
HPV 6 & 11 (16 + 18 → high risk types for neoplastic change)
Nearly always transmitted via sexual contact, spread through skin to skin contact
Genital warts clinical features
Usually asymptomatic & painless
Itching or feeling sore
Psychological distress
Consider internal lesions → bleeding, distortion of urine flow
Peri-anal lesions
Hx of suddenly noticing them/only noticing them once sexual contact
Genital warts differentials
Fordyce spots, pearly papules, skin tags, follicles, sebaceous cysts
Syphilis
Vulval intraepithelial neoplasia, prostatic intraepithelial neoplasia
Molluscum contagiosum
Genital warts mx
Screen for other STIs
Aimed at getting rid of the appearance of the warts but will not clear the virus → body clears over time
No treatment - spontaneously resolve
Destruction - cryoRx, hyfrecation
Anti-mitotic agents
Immune modifiers - imiquimod cream
Surgery
Genital warts referral
Suspicious/uncertain/internal lesions
Recalcitrant lesions
Cervical lesions
Meatal warts
Immunosuppressed, pregnancy, children & young people, elderly patients, high-risk
HPV immunisation
Quadrivalent vaccine protects against subtypes 16&18
Given in school age 12-13 years
Genital warts pregnancy
Common for warts to present in the first time in pregnancy → linked to altered immunological response
Risk of vertical transmission very low
W&W approach, cyro, surgical removal
Vaginal delivery is fine
Genital discharge aetiology
Physiology - pregnancy, sexual arousal
Vaginal - candidiasis, BV, TV
Cervical - gonorrhoea, chlamydia
Genital discharge ix
Examination + pH testing
Vulvovaginal swab - NAAT for G+C, PCR for T, vaginalis
High vaginal swab - culture (T. vaginalis, candida), microscopy (wet mount - TV, gram stain)
Endocervical swab (where relevant) - gonorrhoea
Other tests - culture, HSV PCR, mycoplasma genitalium (VVS PCR)
Anogenital candidiasis
Fungal infection caused by candida yeast
Anogenital candidiasis risk factors
Immunosuppression
Oestrogens
Recent abx
DM
Mucosal breakdown
Recurrent candidiasis ? associated with atopy
Anogenital candidiasis clinical features
Pruritus vulvae - itchiness of the vulva
Vaginal discharge - white, curd-like
Dysuria
O/E - erythema & swelling of the vulva, satellite lesions (red, pustular lesions with superficial white/creamy pseudomembranous plaques that can be scraped off)
Curd-like discharge in vagina
Anogenital candidiasis ix
None are necessary if acute uncomplicated vulvovaginal candidiasis
pH normal (< 4.5)
High vaginal/vaginal wall swab
Anogenital candidiasis mx
Initial course of an intravaginal antifungal - clotrimazole or fenticonazole
Oral antifungal - fluconazole or itraconazole → prescribed as an alternative to the intravaginal mx
Topical imidazole - for vulval sx
Management of candidiasis in pregnancy
Intravaginal antifungal
Do NOT give oral antifungals eg. fluconazole & itraconazole
Treat vulval sx with topical antifungal
Return if sx have not resolved within 7-14 days
Recurrent candidiasis
4 symptomatic episodes/year
Consider alternative diagnosis & concordance
Induction followed by maintenance therapy
Consider host factors → iron deficiency, diabetes
Bacterial vaginosis
Imbalance in vaginal flora
Loss of lactobacilli, elevated pH
Gardnerella, prevotella, M. Hominis
Bacterial vaginosis risk factors
Douching/perfumed products
Cunnilingus
Black race
Recent change in partner
Smoking
Presence of an STI
Bacterial vaginosis clinical features
Offensive fishy smelling vaginal discharge → not usually associated with soreness, itching or irritation
O/E - thin, white/grey, homogenous vaginal discharge
Bacterial vaginosis ix
Clue cells, reduced numbers of lactobacilli, absence of pus cells
pH > 4.5 & KOH whiff test
High vaginal swab
Bacterial vaginosis mx
Metronidazole PO (no alcohol)
Alternative - clindamycin/metronidazole gel
Washing advice
Trichomonas vaginalis
Curable STI caused by the protozoan trichomonas vaginalis
Trichomonas vaginalis clinical features
Female - offensive vaginal odour, abnormal vaginal discharge, itchiness/soreness of the vulva, dyspareunia, dysuria, strawberry cervix
Male - urethral discharge, dysuria, urinary frequency, urethral discharge
Trichomonas vaginalis risk factors
Multiple sexual partners
Unprotected sexual intercourse
Hx of other STIs
Older women
Trichomonas vaginalis investigations
Female - high vaginal swab from posterior fornix
Male - urethral swab or first void urine sample
Trichomonas vaginalis mx
Metronidazole PO
Current partner & any other sexual partners in preceding four weeks should be tested & treated
Abstain from sexual intercourse
Trichomonas vaginalis pregnancy
May carry a risk of premature labour & baby having a low birth-weight
At delivery → may predispose to maternal postpartum sepsis
Metronidazole can also affect taste of breast milk → high dose is avoided
Neisseria gonorrhoea
Gram negative intracellular diplococci
Transmitted through direct inoculation of infected secretions
Neisseria gonorrhoea clinical features
Urethral - mucopurulent discharge, +/- dysuria
Endocervical - altered discharge, dysuria, dyspareunia, lower abdo pain
Rectal - asymptomatic, anal discharge, pain
Phayngeal - asymptomatic, sore throat
Neisseria gonorrhoea risk factors
Aged < 25 years
Men who have sex with men
Living in high density urban areas
Previous gonorrhoea infection
Multiple sexual partners
Neisseria gonorrhoea ix
Gonorrhoea culture - taken in all cases prior to treatment for AMR
NAAT
Microscopy
Neisseria gonorrhoea mx
Ceftriaxone IM - 1st line
If antimicrobial susceptibility known - ciprofloxacin 500mgms stat dose
Screening for other STIs, further safe sex practices
Neisseria gonorrhoea complications
Disseminated infection - pustular lesions, joints, tendon involvement
Transluminal spread - PID, prostatitis, epididymo-orchitis
Neisseria gonorrhoea pregnancy
May be associated with complications such as perinatal mortality, spontaneous abortion, premature labour & early fetal membrane rupture
Vertically transmitted during delivery → neonatal conjunctivitis → prophylactic abx can be given to prevent this
Chlamydia trachomatis clinical features
Asymptomatic
Female genital tract - discharge, PCB, IMB, dysuria, LAP, deep dyspareunia
Penile urethra - urethral discharge, dysuria
Rectal infection - asymptomatic, anal discharge, anorectal discomfort
Pharyngeal - no sx
Conjunctiva - low grade, unilateral irritation
Chlamydia trachomatis ix
Women - vulvovaginal swab, endocervical swab or first catch urine
Men - first catch urine sample or urethral swab
NAAT
Chlamydia trachomatis mx
Doxycycline PO or azithromycin single dose
Avoid sex until they and/or their partner have completed treatment
Chlamydia trachomatis complications
PID
Epididymitis or epididymo-orchitis
Reactive arthritis
Non-specific urethritis
Describe the presence of urethritis when a gonococcal bacteria are not identifiable or the initial swab
Non-specific urethritis aetiology
Chlamydia trachomatis
Mycoplasma genitalium
Less common - ureaplasma urealyticum, tichomonas vaginalis, e. coli
Non-specific urethritis ix
NAAT
Urine
HSV
Non-specific urethritis mx
Contact tracing
Doxycycline PO
Azithromycin - mycoplasma genitalium
