STIs (Gonorrhea, Chlamydia, Syphilis) Flashcards

1
Q

Under IDA, notification should be done within ___h of diagnosis

What is the purpose of notifying?

What data must be notified?

A

72h

Notification purpose: monitoring and evaluating national control programmes, NOT for detection/contact tracing

Only demographic data (age, gender, ethinicity, nationality) requied for epidemiologic analysis

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2
Q

Partner notification is only mandatory for _____

A

HIV/AIDS

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3
Q

What are the modes of transmission of STIs?

A
  • Sexual contact
  • Direct contact of broken skin with open sores, blood, genital discharge
  • Receiving contaminated blood
  • Infected mother to child (pregnancy, childbirth, breastfeeding)
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4
Q

Classify the STIs into the following categories:

  1. Transmitted during pregnancy (across placenta, in utero)
  2. Transmitted during childbirth (maternal blood contact)
  3. Transmitted during breastfeeding
A
  1. Pregnancy: Syphilis, HIV
  2. Childbirth: Chlamydia, Gonorrhea, HSV, HIV
  3. Breastfeeding: HIV
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5
Q

Can STIs be transmitted through kissing?

A

Not in dry kissing
But may in deep wet kissing as gonorrhea, chlamydia, syphilis, herpes can be present in the mouth/throat of the infected person

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6
Q

What are the risk factors for STIs?

A
  • Unprotected sexual intercourse (condom)
  • Number of sexual partners/sexual contact with people who have multiple sexual partners
  • MSM
  • Prostitution (CSW)
  • Illicit drug use - contaminated needle, risky sexual behaviour
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7
Q

What are some individual prevention methods for STIs?

A
  • Abstinence, reduction of number of sexual partners
  • Barrier contraceptive (condoms)
  • Avoid drug abuse, avoid sharing needles
  • Pre-exposure vaccination (for HPV, Hep B)
  • Pre- and Post-exposure prophylaxis (for HIV only)
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8
Q

Why is the management and prevention of STIs important?

A
  1. Reduce related morbidity, progression to complicated disease
  2. Prevent HIV infection
  • incr risk of HIV acquisition in pt w gonococcal, syphilis, and genital herpes
  1. Prevent serious complications in women
  • STIs are main preventable cause of infertility (gonorrhea and chlamydia can damage fallopian tube and womb)
  • Prevention of HPV reduces no. of women with cervical cancer, and reduces anal and rectal cancer in men
  1. Protect the babies
  • Untreated STIs cause congenital and perinatal infections in the neonates, premature deliveries, neonatal death or stillbirth
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9
Q

Compare the incubation periods of the various STIs

A

Short incubation period (2 days to 3 weeks)
- Gonorrhea
- Chlamydia
- Genital Herpes

Long incubation period (2 weeks to months)
- Syphilis

Longer incubation period (several years)
- HIV

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10
Q

[GONORRHEA]

What bacteria causes gonorrhea?
How does it appear on gram stain?

A

Neisseria gonnorhoeae

Intracellular gram-negative diplococci (pink)

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11
Q

[GONORRHEA]

Transmission via?

A
  • Sexual contact
  • During childbirth
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12
Q

[GONORRHEA]

How is it diagnosed?

A
  1. Gram-stain of genital discharge
  2. Culture
  3. NAAT (urine PCR)
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13
Q

[GONORRHEA]

Uncomplicated gonorrhea affects the __________ area

If left untreated, can infect various sites and cause:

A

Uncomplicated urogenital gonorrhea

If left untreated:
- Urethritis
- Cervicitis
- Proctitis
- Pharyngitis
- Conjunctivitis
- Disseminated

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14
Q

[GONORRHEA]

Individuals may be asymptomatic.

If symptomatic, what is the presentation of uncomplicated urogenital gonorrhea for males and females respectively?

A

MALES:
- Purulent urethral discharge
- Dysuria
- Urinary frequency

FEMALES:
- Mucopurulent vaginal discharge
- Dysuria
- Urinary frequency

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15
Q

[GONORRHEA]

What are some complications that can arise from untreated gonorrhea? (males and females respectively)

A

MALES:

  • Epididymitis
  • Prostatitis
  • Urethral stricture
  • Disseminated disease

FEMALES:

  • Pelvic inflammatory disease
  • Ectopic pregnancy (since gonorrhea can affect the fallopian tube)
  • Infertility
  • Disseminated disease

In BOTH:

  • Disseminated disease: skin lesions, tenosynovitis, monoarticular arthritis
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16
Q

[GONORRHEA]

Which class of antibiotics is no longer used in the management of gonorrhea due to increasing resistance?

A

Fluoroquinolone
- increasing resistance to ciprofloxacin

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17
Q

[GONORRHEA]

Treatment of gonococcal infection should be accompanied by _________

A

Anti-chlamydia therapy

*Unless chlamydia infection has been excluded

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18
Q

[GONORRHEA]

What is first line for the management of uncomplicated urogenital gonococcal infections?

A

IM Ceftriaxone 500mg, single dose (for <150kg)

IM Ceftriaxone 1g, single dose (for >=150kg)

If Chlamydia not excluded,
+ PO Doxycycline 100mg BD x7d

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19
Q

[GONORRHEA]

What are the alternatives for the management of uncomplicated urogenital gonococcal infections?

A
  • IM Gentamicin 240mg + PO Azithromycin 2g single dose
  • PO Cefixime 800mg single dose (+ PO Doxycycline 100mg BD x7d)
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20
Q

[GONORRHEA]

Is test of cure recommended for gonococcal infection?

A

US CDC - not required unless symptoms persists

DSC - recommended (worried of Ceftriaxone resistance)

21
Q

[GONORRHEA]

Explain the management of sex partners

A
  1. Sex partners in last 60 days should be evaluated and treated. If last exposure >60d, then treat the most recent partner
  2. To minimize disease transmission, abstain from sexual activity for 7 days after treatment and resolution of symptoms
  3. To minimize risk for reinfection, abstain from sexual intercourse until all sex partners have been treated
22
Q

[CHLAMYDIA]

Chlamydia infections are caused by what bacteria?

A

Chlamydia trachomatis (atypical)

23
Q

[CHLAMYDIA]

Transmitted via?

A
  • Sexual contact
  • During childbirth
24
Q

[CHLAMYDIA]

How is it diagnosed?

A

NAAT (PCR - urine or genital swab)

*Recall atypicals don’t appear well on gram stains

25
Q

[CHLAMYDIA]

What is the clinical presentation?

A

SImilar to gonorrhea, but possibly milder

  • Purulent discharge, dysuria, urinary frequency
  • Can infect various sites, and cause complications as per gonorrhea (e.g., infertility, ectopic pregnancy in women, epididymitis, prostitis in men, disseminated disease)
26
Q

[CHLAMYDIA]

What is the first line management?

A

PO Doxycyline 100mg BD, x7d

27
Q

[CHLAMYDIA]

What are the alternative management?

A

PO Azithromycin 1g single dose

OR

PO Levofloxacin 500mg once daily, x7d

28
Q

[CHLAMYDIA]

Explain the following:
- Why Doxycyline as first line
- Why Erythromycin is not recommended
- Why other FQs are not recommended

A
  1. Doxycyline is first line due to better cure rates
  2. Erythromycin is not recommended due to GI SEs that reduce adherence (gastric distress and motility - it is a motilin agonist)
  3. Levofloxacin is the only FQ effective against Chlamydia
29
Q

[CHLAMYDIA]

Azithromycin may be used as first time if adherence is a concern (since it is single dose)

Explain the PK reasons as to why Azithromycin can be given 1g as a single dose for Chlamydia

A

Azithromycin:

  • Long intracellular half-life (60-70h, 68h) vs serum half life (12h)
  • Drug able to stay in WBC for next 3 days
30
Q

[CHLAMYDIA]

Is test of cure required? Why or why not?

A

Not required as treatment for Chlamydia is highly effective
Less concerns of resistance etc.

Only required for specific concerns such as pregnancy, non-adherence, or if symptoms persist

31
Q

[CHLAMYDIA]

Explain the management of sex partners

A
  1. Sex partners in last 60 days should be evaluated and treated. If last exposure >60d, then treat the most recent partner
  2. To minimize disease transmission, abstain from sexual activity for 7 days after single dose treatment or until completion of a 7 day regimen, and resolution of symptoms
  3. To minimize risk for reinfection, abstain from sexual intercourse until all sex partners have been treated
32
Q

[SYPHILIS]

Syphilis is caused by which bacteria?

A

Treponema Pallidum (spirochete)

33
Q

[SYPHILIS]

Transmitted via?

A
  • Sexual contact
  • During pregnancy (transplacental/in utero)
34
Q

[SYPHILIS]

There are various stages of syphilis based on the clinical presentation.

Briefly describe each stage.

A
  1. Primary - more localised (painless ulcers/chancre at genital, anus, mouth) (may also have multiple, painful lesions)
  2. Secondary - more systemic (hematogenous and lymphatic spread can cause skin rash, mucocutaneous lesions, patchy alopecia, lymphadenopathy)
  3. Latent (early <1y, late >1y) - asymptomatic, internal organs affected, picked up by serology testing, determine based on pt history taking
  4. Tertiary - involve heart, eye, bones, joints (a/w cardiac involvement, blindness, gummatous lesions in joints - impaired movement)
  5. Neurosyphilis - CNS involvement (cognitive dysfunction, S&S of meningitis and stroke)
35
Q

[SYPHILIS]

What are the two ways to diagnose syphilis?

A
  1. Darkfield microscopy of exudates from lesions (appear as wriggly spirochetes)
  2. 2 serological blood tests - treponemal and non-treponemal tests
36
Q

[SYPHILIS]

Describe the treponemal test

A

Treponemal test
[E.g., T. Pallidum Haemagglutination test (TPHA), T. Pallidum Passive Particle Agglutination Assay (TPPA)]

  • Uses the treponemal antigen to detect treponemal antibody
  • More sensitive and specific than non-treponemal test
  • Used as a confirmatory test
  • Qualitative test: positive or negative result
  • May remain reactive for life, not used for monitoring response to treatment
37
Q

[SYPHILIS]

Describe the non-treponemal test

A

Non-treponemal test
[E.g., venereal disease research laboratory slide test (VDRL), rapid plasma reagin card test (RPR)]

  • Uses nontreponemal antigen (cardiolipin) to detect treponemal antibodies
  • Positive test indicate presence of any stage of syphilis
  • Less specific, need treponemal test to confirm
  • Quantitative test: result reported is the most dilute serum conc. with a positive reaction
  • Antibody titres correlate with disease activity, used to monitor response to treatment (VDRL and RPR are not interchangeable)
  • Non-treponemal test tItres decline after treatment, and can become non-reactive
38
Q

[SYPHILIS]

Recall the 2 main antibiotics that have activity against spirochetes

A
  1. Penicillin G
  2. Tetracyclines
39
Q

[SYPHILIS]

Explain the normal regimen for primary/secondary/early latent syphilis

A

IM Benzathine Penicillin G 2.4MU x1 dose

*Benzathine - distribute into storage tissue, prolonged release over a week

40
Q

[SYPHILIS]

Explain the penicillin-allergic regimen for primary/secondary/early latent syphilis

A

PO Doxycyline 100mg BD x14d

*Counsel: take w food to reduce GI upset, take w full glass of water, remain upright for at least 30min to prevent esophagitis and heartburn, space 2h apart from multivalent ions
*SE: GI upset, photosensitivity

41
Q

[SYPHILIS]

Explain the normal regimen for late latent/tertiary/unknown duration syphilis

A

IM Benzathine Penicillin G 2.4MU once a week x3 dose

42
Q

[SYPHILIS]

Explain the penicillin-allergic regimen for late latent/tertiary/unknown duration syphilis

A

PO Doxycyline 100mg BD x28d

43
Q

[SYPHILIS]

Explain the normal regimen for neurosyphilis

A

IV Crystalline Pen G 3-4MU q4h x10-14d

OR

IV Crystalline Pen G 18-24MU/day as a continuous infusion x10-14d

OR

IM Procaine Pen G 2.4MU once daily + PO Probenecid 500mg qid x10-14d

*Procaine - distribute into storage tissue, prolonged release over a day
*Probenecid inhibits renal tubular secretion of penicillin, thereby increasing its conc. and prolonging its effect

44
Q

[SYPHILIS]

Explain the penicillin-allergic regimen for neurosyphilis

A

IV/IM Ceftriaxone 2g once daily x10-14d

*They do not share common R1 side chain, hence lower risk of cross-sensitivity
*However if there is still concern for cross-sensitivity:
- skin test to confirm penicillin allergy
- desensitization

45
Q

[SYPHILIS]

What reaction might cause fever to develop within the first 24h of syphilis treatment?

A

Jarisch-Herxheimer reaction: acute febrile reaction accompanied by haedache and myalgia (occur within first 24h after therapy)
Antipyretics will help but not prevent

46
Q

[SYPHILIS]

How to monitor for therapeutic response with syphilis treatment?

A

Monitoring for primary/secondary/latent:

  • Quantitative VDRL/PRP at 3, 6, 12, 18, 24 months
  • Treatment success = dcr of VDRL/RPR titre by at least 4 fold

Monitoring for neurosyphilis:

  • CSF examination (draw via lumbar puncture) every 6 months until CSF normal (examine cell count, protein content etc.)
47
Q

[SYPHILIS]

What is defined as treatment failure at 6 months for syphilis treatment?

A

Treatment failure at 6 months when:

  • Show signs and symptoms of the disease
  • Failure to dcr VDRL or RPR titre by 4 fold, or increase in titre

=> Retreat and reevaluate for unrecognized neurosyphilis

48
Q

[SYPHILIS]

Explain the management of sex partners

A
  • All at risk sexual partners should be evaluated for STIs and treated it tested positive
  • Persons who receive syphilis treatment must abstain from sexual contact with new partners until syphilis lesions are completely healed (*careful assessment of response and symptoms resolution by the doctor)