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Flashcards in HIV & STIs Deck (39)
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1
Q

What are the key symptoms presenting with STI?

A
  • urethral, vaginal discharge
  • lower abdo pain
  • genital lumps, ulceration
  • genital itching
  • rectal symptoms
2
Q

What are the four ‘core’ STIs tested for at sexual health clinics, and how are they tested for in men and women?

A
  • Chlamydia trachomatis (CT)
  • Neisseria gonorrhoeae (GC; gonococcus)
  • HIV
  • Syphilis
  • GC/CT tested for by vulvovaginal swab (VVS) in women, and by first void urine (FVU) in men.
  • consider throat and rectum swabs in MSM
  • high vaginal swab (HVS, Amies swab) in recurrent/persistent discharge, postpartum or post gynae surgery, PID etc.
  • HIV and syphilis via serology
3
Q

Describe the swab findings in a positive case of GC infection.

A
  • > 5 polymorphs per high powered field indicates urethritis
  • look for gonococcal cells (these are purple gonococci within cells)
  • NB CT cannot be seen on gram stain
4
Q

Name the three categories of serovar seen in CT and which infection types they may cause.

A
  • A-B: ocular infection
  • D-K: urethritis, epididymo-orchitis, neonatal pneumonia and conjunctivitis
  • L1-3: LGV (lymphogranuloma venereum), mainly MSM with rectal symptoms
5
Q

Name the clinical features of CT.

A
  • milky urethral discharge, irregular bleeding, abdominal pain, dysuria
  • inflammation of urethra, cervix, epididymis, rectum
  • [neonatal pnuemonia, conjunctivitis]
6
Q

What is Fitz Hugh-Curtis Syndrome?

A

A very rare presentation of CT, with perihepatitis and piano-string adhesions

7
Q

Describe the management of CT.

A
  • doxycycline 100mg BD/wk
  • azithromycin 1g stat + 500mg OD/2days; this is second line and should only be used when tetracyclines genuinely cannot be taken (e.g., during pregnancy) due to antibiotic resistance
8
Q

What are the complications of CT?

A
  • ectopic pregnancy
  • PID (manage with ceftriaxone, doxycycline, metronidazole)
  • reactive arthritis
  • reinfection (1/5)
9
Q

Describe the symptoms and management of NG.

A
  • men: anterior urethritis, mucopurulent discharge, dysuria
  • female: vaginal discharge, dysuria, PCB/IMB, lower abo pain
  • rarer: proctitis, sepsis/DGI, tenosynovitis, arthritis, erythematous skin
  • 1st line ceftriaxone 1g IM stat
  • 2nd line ceftaime 400mg PO + azithromycin 2g PO (if infection C/I / rejected)
  • test of cure in all patients 2 weeks following treatment
10
Q

What are the complications of GC?

A
  • Bartholin abscess
  • ascending infection (endometritis, hydrosalpinx, PID)
  • abscess (periurethral, rectal)
  • infertility, ectopics
11
Q

What are the most common causes of non-gonococcal urethritis (NGU)?

A

CT, mycoplasma genitalium, ureaplasma urealyticum, TV, HSV 1/2, adenoviruses

12
Q

What is the wider differential diagnosis for genital ulceration?

A

vIndIcATe

  • infectious (HSV, VZV, EBV, HIV)
  • iatrogenic (drug eruption, SJS)
  • autoimmune (Crohn’s, Behcet’s, lichen sclerosus)
  • trauma (self-harm, artefacta)
13
Q

Describe the timeline of HSV infections.

A
  • primary: virus ascends peripheral sensory nerves to DRG, establishing latency.
    • symptoms: ulcers, inguinal lymphadenopathy, viraemia, dysuria, vulval pain
  • non-primary genital infection: those with previous HSV1/2 who acquire the other type.
    • cross-protection from other type means a milder illness
  • recurrent infection: 4x more common in HSV2 than 1
    • tingling, itching, pain, unilateral ulcer, can be asymptomatic
    • usually resolves 5-7days, although all episodes potentially infectious
14
Q

Describe the management of HSV-caused genital ulceration.

A
  • primary infection: saltwater bathing, topical anaesthetic (5% lidocaine), and acyclovir (400mg TDS 6/7 days).
  • avoid sharing towels, etc. to prevent autoinoculation
  • suppressive therapy offered with >6 recurrences/yr. This is acyclovir 400mg OD
15
Q

Describe the natural history of syphilis.

A
  • a chronic systemic disease caused by Treponema pallidum, a motile spirochete
  • early infection [primary, secondary, early latent <2yr], and late non-infectious [late latent >2yr, tertiary]
  • incubation 9-90 days with primary papule at site of inoculation which ulcerates to form a chancre
  • secondary: widespread rash on palms/soles, anterior uveitis, condylomata lata (highly infectious plaques)
  • tertiary: gummatous syphilis. can affect cardiovascular and neurological systems
16
Q

Describe the investigations used for syphilis.

A
  • cannot be cultured
  • dark field microscopy, PCR, or serology (IgM/IgG ELISA)
  • non-treponemal tests: VDRL, RPR
  • treponemal tests: TPPA, ELISA, INNO-LIA, FTS antibodies
17
Q

Describe the management of syphilis.

A
  • single dose of 2.4 MU benzthine penicillin G IM stat
  • doxycycline 100mg BD 2/52
  • late syphilis: penicillin G IM weekly for 3 wk
  • followup until RPR -ve or serofast. Titres should decrease fourfold by 3-6m
18
Q

Which HPV subtypes are covered by the quadrivalent vaccine, and what pathologies do these cause?

A
  • HPV 6/11: viral warts

- HPV 16/18: oncogenic

19
Q

Describe the pathology of HPV infection and the main management options.

A
  • warts appear at sites of trauma during sex (prepuce/glans, fourchette, vulva, perineum)
  • non-hair-bearing skin: soft and non-keratinised
  • hair-bearing skin: firm and keratinised
  • topical podophyllotoxin, imiquimod, ablation (cryotherapy, electrocautery)
20
Q

Name the partner notification (PN) periods for CT, GC, NGU, TV, PID, HIV, and syphilis.

A
  • CT: male urethral 4w, others 6m
  • GC: half of CT (2w/3m)
  • NGU/TV: 4w
  • PID: 6m
  • HIV: 4w before last negative result, or 4w before most likely infection
  • syphilis: primary 90 days, secondary 2yr
21
Q

For which sexual infections is partner notification (PN) not required?

A
  • warts, herpes
  • thrush
  • bacterial vaginosis
22
Q

Describe the pathology of most cases of bacterial vaginosis (BV).

A

A lack of lactobacilli allows overgrowth of pathogenic bacteria (including Gardnerella vaginalis, anaerobes, mycoplasmas, and Mobiluncus spp.)
An increased pH can lead to prolonged/heavy periods

23
Q

Describe the clinical features and management of BV.

A
  • increased vaginal discharge, offensive fishy odour, creamy-white homogenous discharge which may be frothy
  • amine production causes offensive odour and froth
  • metronidazole 400mg BD 5-7/7
  • alternatives: intravaginal metronidazole, intravaginal clindamycin
24
Q

Name the key viral proteins expressed on the HIV particle.

A
  • p10 (protease - processes viral genome RNA)
  • p17, p24, gp120 (transcribes viral mRNA)
  • p32 (integrase - integrates viral DNA into CD4 cells)
  • gp41 - binds CD4 cells, inc. CCR5 receptors
25
Q

Describe the main types of HIV, and how their epidemiology varies.

A
  • HIV-1: accounts for most cases worldwide. subgroups include
    • M (major, 98%)
    • N (new)
    • O (outlier)
    • P (single patient in Cameroon)
  • HIV-2: localised mainly to sub-Saharan Africa
26
Q

Describe the viral lifecycle of HIV.

A
  1. binding (gp41)
  2. fusion
  3. reverse transcription
  4. integration (p32)
  5. replication
  6. transcription (p10, gp160, p24, p17)
  7. viral budding
27
Q

Describe the changes HIV infection causes on CD4 and CD8 cells.

A
  • decreasing circulating CD4 cells and proliferation
  • increased proliferation of CD8, but decreased activation (dysregulated cytokines)
  • reduced cross-switching of antibodies and subsequent affinity
28
Q

There are three main stages of HIV infection. Name these and describe how CD4 cell count and viral RNA copies change during these times.

A
  1. acute HIV syndrome: rapid reduction of CD4, rapid increase in viral RNA over weeks (0-9wk)
  2. clinical latency: reduction in viral load and increased number of CD4 cells; these gradually increase/decrease respectively over years
  3. AIDS: viral load rapidly increases. CD4 count rapidly decreases.
29
Q

Describe the clinical features of the acute HIV syndrome (stage 1/3).

A

fever, maculopapular rash, myalgia, pharyngitis, aseptic meningitis, headache
very high risk of transmission

30
Q

Describe the clinical features of clinically latent HIV infection (stage 2/3).

A
  • neuro: distal sensory polyneuropathy, mononeuritis multiplex, vascular myopathy, aseptic meningitis, GBS, neurosyphilis
  • CVS: dec. HDL, increased IHD, cardiomyopathy, CHF, and myocarditis
  • GI: weight loss, diarrhoea, encephalopathy, hypochlorrhydria
  • endocrine: reduced testosterone, abnormal adrenal function
  • renal: HIVAN, nephrotic syndrome
  • haem: lymphopenia, anaemia, neutropenia, isolated thrombocytopaenia
31
Q

Name the main AIDS-defining syndromes (stage 3/3).

A
  • pulmonary (pneumocystis jiroveci, TB)
  • neurological (toxoplasma gondii, PML by JC virus
  • CMV (retinitis, colitis, and/or encephalopathy)
  • viral (VZV, HSV; more extensive and recurrent)
  • neoplasia: HHV8 (Kaposi sarcoma), EBV (non-Hodgkin, Burkitt lymphoma)
32
Q

Name the main methods of transmission of HIV.

A
  • sex (raised in MSM, trauma, ulceration, concurrent STI)
  • parenteral (PWIDs, contaminated blood and blood products)
  • mother-to-child (transplacental, perinatal, breastfeeding)
33
Q

Who do we screen for HIV?

A
  • universal, where prevalence >0.2% (NHS Lothian)
  • GUM clinics, antenatal services, TOP services, drug dependency programmes, care for TB/HBV/HCV/lymphoma
  • high-risk: those with STI, partners of those with HIV, MSM and their F contacts, PWIDs, those from countries of high prevalence
  • those with indicator conditions
34
Q

Name the drug classes used in the treatment of HIV.

A
  • NRTIs (nucleoside reverse transcriptase inhibitors)
  • NNRTIs (non-NRTIs)
  • integrase inhibitors
  • protease inhibitors
  • coreceptor (CCR5) inhibitors
  • fusion inhibitors (very expensive, S/C, last option)
  • [in development: capsid, monoclonal antibodies, maturation-based drugs]
35
Q

Describe the makeup and purpose of HAART.

A
  • combination of 3 drugs, from which at least 2 are classes to which the virus is susceptible.
  • 2 NRTIs + 1 other agent
  • reduce viral load, restore immunocompetence, reduce morbidity, mortality, and transmission.
36
Q

Describe and give examples of primary and secondary prevention of HIV.

A
  • primary prevention: acquiring HIV. condoms, regular tests, behaviour change, PEP/PrEP, PMTCT, circumcision, needle exchange
  • secondary prevention: onward transmission. condoms, regular tests, behaviour change, disclosure, PMTCT, needle exchange
37
Q

What are the criteria for PrEP?

A
  • MSM condomless anal sex, 2+ partners in the last year, sex likely in the next 3m
  • rectal bacterial STI in last year
  • partner of someone with HIV who does not have suppressed viral load.
38
Q

When is PEP initiated?

A

<72h after possible exposure to HIV (occupational, sexual). Taken for 4 weeks.

39
Q

Describe PMTCT.

A
  • prevention of mother to child transmission
  • achieved with HAART during pregnancy
  • vaginal delivery undertaken with an undetectable viral load
  • C/S done with a detectable viral load.