Sexually Transmissible Infections

Question 1

which organism causes gonorrhoea? how does it present in men and women?

Answer 1

nisseria gonorrhoeae, a gram neg diplococci.
adheres to columnar epithelium of cervix and urethra. incubates for 2-7 days.

asymptomatic infection is common in females (80%). More likely to see symptoms (urethritis) in males (10% asymptomatic).

0. 5-3% of cases may disseminate and present as:
   - arthritis
   - meningitis
   - endocarditis
   - epididymitis
   - peri-hepatitis (RUQ pain, LFT’s aberrant, pleuritic pain)

In the mouth:
-pharyngitis
lymph adenopathy

Women:
Pelvic Inflammatory Disease (PID)
-tubal scarring
-infertility (10-20%)

Males:
-thick, creamy, yellow, urethral discharge

Question 2

how does gonorrhea present in neonates?

Answer 2

• gross purulent conjuctivitis
• day 2-5 of life–>perforation and blindness

-flush out eyes regularly, treat mother and sexual contacts

Question 3

standard tx for gonorrhoea?

Answer 3

combo tx with ceftriaxone (IM/IV) and oral azithromycin (targets 50s ribosome, affecting protein synthesis in the organism)

combo to prevent abx resistance

Question 4

which organism causes chlamydia? how does it present in men and women?

Answer 4

chlamydia trachomatis, an obligate intracellular parasite, attaches to columnar epithelium. 48-72hr life cycle.

based on the serovar involved (3 main subtypes), may cause genital infection, lymphogranuloma venereum (LGV), ocular infection.

in Men:

• Dysuria
• meatal erythema
• clear urethral discharge
• testicular pain (epididymo-orchitis)
• prostatitis

In women:

• urethritis/dysuria
• cervicitis, endometritis/vaginal discharge
• irregular bleeding
• pelvic pain and dyspareunia
• acute and chronic Pelvic Inflammatory Disease (PID)
• ->scarring and infertility

Question 5

the life cycle of chlamydia consists of elementary bodies and reticulate bodies, what is their respective purposes?

Answer 5

elementary bodies are infection, non-replicating, hardy

reticular bodies are metabolically active and replicate.

Question 6

what is the most common STI infection?

Answer 6

chlamydia (20%)

Question 7

how does chlamydia present in neonates?

Answer 7

50% transmission rate from mother.

• 25% conjuctivitis (hemorrhagic conjuctivitis)
• 10% pneumoniae (pneumonitis)

Question 8

standard tx for chlamydia?

Answer 8

azithromycin or doxycyline (not in pregnant mothers b/c tetracyclines will stain the baby’s teeth)

Question 9

how is gonorrhea diagnosed?

Answer 9

• cervical swap put in charcoal
• male urethral swab
• first void urine of accumulated urine
• other sites of infection (conjuctiva, csf, blood, anal, pharynx, synovial fluid)
• NAAT (nucleid acid amplification tests) on first void urine or cervical swabs
• detects co infection of nisseria and chlamydia

Question 10

how is chlamydia diagnosed?

Answer 10

• first void urine
• cervical swab
• anal swab
• NAAT

NB: followed up by test of cure in 4-6 weeks and again in 3 months

Question 11

what is trichomonas vaginalis and how does it present? how is it tx?

Answer 11

flagellated protozoon. sexually transmitted.

• often asymptomatic.
• may present as frothy, green-yellow vaginal discharge, pH >5.0
• cervical arythema, friability, “strawberry cervix”
• pruritis, dysuria, and abdominal pain

NB: associated with high risk sexual activity, marijuana use, and being indigenous.

Question 12

how is trichomonas vaginalis dx and tx?

Answer 12

Dx:

• High vaginal swab (HVS) –>culture or wet prep microscopy (not very sensitive but $10)
• Urine –>PCR (highly sensitive but $40)

Tx:

• metronidazole oral
• tinidazole oral

Question 13

Which STI is caused by Treponema Pallidum? how does it present?

Answer 13

T Pallidum causes Syphilis!

Primary syphilis presents as a sore/lesion called a ‘chancre’
Secondary syphilis presents 2-8 weeks later as a generlized non-itchy rash.
Tertiary syphilis presents 10-20yrs later as a gumma (granuloma) in brain, skin, bone, genitals, etc.

Question 14

how is treponema pallidum detected? tx?

Answer 14

• microscopy
• serology: treponemal (VDRL, RPR) and non treponemal tests (TPHA, EIA, FTA-Abs)

NB:
non-treponemal are useful for screening and monitoring therapy. but cause lots of false positives.
treponemal are positive early, and positive for life.

Tx with IV penicillin or if allergic, tetracycline

Question 15

mycoplasma genitalium? present? dx? tx?

Answer 15

pathogenic bacterium that lives on urinary and genital epithlium tracts. no cell wall, cant gram stain. smallest genome of any living organism.

Present:
Men - urethritis
Women - cervicitis, acute endometritis, pelvic inflammatory disease (PID) post-termination of pregnancy, assoc wtih pre-term delivery, increased risk of HIV

Dx: NAAT (can’t culture it)

Tx:
Highly abx resistant
-Azithromycin
-Moxyfloxacin