3. Sexually Transmissible Infections Flashcards
What infections are transmitted via the Oral-genital contact?
- Chlamydia, Gonorrhoea, HSV, Syphilis, HPV
What infections are transmitted via the Anilingus?
- Amoeba, Cryptosporidia, Giardia, Shigella. HAV
What are the routes of transmission of STI?
- Oral-genital contact - Vaginal intercourse - Anal intercourse - Anilingus
What should you ask about a patient coming in with an STI?
- Partners
- M/F
- Number/monogamous
- Pregnancy prevention?
- Protection from STI
- How do you protect against STI and HIV
- Practices
- Vaginal, Oral anal
- Past history of ST
What are the possible causes for discharge?
- Gonorrhea
- Chlamydia
- Trichomonas - Frothy green-yellow discharge
- Bacterial vaginosis - White-grey fishy smell (polymicrobial growth)
- Candidasis - Cottge cheese (not sexually transmitted)
- Mycoplasma genitalium
What are the possible causes for STI ulcer?
- HSC
- Syphillis
- Chancroid
- LGV
- Granuloma inguinale
What are the clinical patterns of STI?
- Discharge
- Ulcer
- Pelvic inflammatory disease
- Dermatological
What are the diagnostic tools for STI?
- Microscopy
- Vaginal fluid, gram stain
- Culture
- Serology
- Syphilis, HIV
- Nucleic acid ampification test
- Geonorhea, Chlamydia, M.Genitallium
- Urine, Uretheral, vaginal, cervical swabs.
What are the features of Nisseria gonorrhoeae?
- Gram negative diplococci
- Adhere to columnar epithelial cells
- Produce various toxins and immune modulators that help them survive. Also modify surfae protein to hide from immune system.
- Incubation period: 2-7 days
- Asymptomatic infection in females (80%)
- Males - Urethrtis (10%)
- Increasing antibiotic resistance
What can happen if Gonorrhoea is left untreated?
If left untreated dissemination (0.5-3%) could cause
- Arthritis
- Macrulopapular rash
- Meningitis
- Endocarditis
- Epididymitis
-
Peri-hepatitis (Fitz-Hugh-Curtis syndrome)
- Adhesion of liver capsule to abdominal cavity wall
- Increased risk post menses
- Violin string adhesion
If Gonorrhoea is left untreated and lead to Pelvic Iflammatory disease what are the sequalae?
- Tubal scarring
- Infertility (10-20%)
What happens if babies are born with Gonno infected moms?
Neonatal gonococcal opthalmia
- Gross purulent conjunctivitis
- Day 2-5 of life –> Perforation and blindness
- Mild disease indistinghuishble from other causes of conjunctivitis
Treatment
- Cefotaxime IV
- Topical antibiotic not required
- Irrigate eyes regularly
- Treat mother + sexual contacts
What diagnostic specimens are used for Gonno?
Cervical swab into charcoal transport
Male urethral swabs
urine
Other specimens: conjunctiva, pharynx, skin lesions, anal, CSF, blood, synovial fluid.
What laboratory investigations can be used to diagnose Gonno?
- Non-selective: Chocolate blood agar in CO2
- Selective: Thayer-Martin agarTM
- Colistin (GN), Vancomycin (GP), nystatin (fungi)
- Culture for antibiotic sensitivies
What is nucleic amplification tests and what is it used for?
Use genital (cervial or vaginal) swabs or first void urine.
Used to detect Gonno
Combined Chlamydia and Nisseria detection (Chlamydia co-infection in 50%)
What are the treatments for Gonno?
Use high dose, single dose IV
Azithromycin 1g (Chlamydia)
and
Ceftriazone 500mg (IM/IV) (Gonno)
Ciproflaxacin 500mg oral if sensitive
Amoxicillin 3g + Probenecid 1g oral
How do you prevent Gonno?
- Barrier contraception
- Contact tracing
- Vaccine???
What are the features of Chlamydia infection?
- Most common STI (2-20%)
- Females: Cervicitis
- Male: Urethritis
- [Anus, Conjunctivitis]
- Frequently asymptomatic
- Obligate intracellular parasite
- Infects Columnar epithelium
- Infects young female adults
- Serovars
- D-K: Genital Infection
- L 1-3: Lymphogranuloma venerum (LGV)
- A-C: Ocular infection (Trachoma)
- 48-72 hours life cycle
- Elementary bodies: infectious, non-replicating, hardy
- Retriculate bodies: Metabolically actve, replicate
What is the life cycle of Chlamydia?
What are the clinical findings of Chlamydia in men?
- Dysuria
- Meatal erythema
- Clear urethral discharge (may need to milk to produce discharge)
- Testicular pain (Epididmo-orchitis)
- Prostasis
What are the clinical findings of Chlamydia in women?
- Cervitis, endometrisis/vaginal discharge
- Urethritis/Dysuria
- Irregular bleeding
- Pelvic pain & dyspaeunia
Pelvic inflammatory disease
- Acute and chronic
What happens when Chlamydia invades the lymph node?
- LGV (Lymphogranuloma venereum)
- Ulcerative genital lesion –> Suppurative inguinal lymphadenopathy with systemic Sx
- Proto-colitis with strictures (MSM)
- Endemic in Africa, India, SE Asia, South America
What happens in Neonatal Chlamydia?
50% Transmission
- 25% conjunctivitis
- 10% pneumonia
Colonization may persists
Conjunctivitis IP 2-28 days
Pneumonia IP 2-8 weeks
What laboratory investigations are done for Chlamydia?
- Cervical/Urethral/Anal swab
- Urine
- Nucleic Acid detection
- Culture not routine and requires cell culture techniques
- Test of cure required
- Post procedure
- Prgnancy
What are the treatments for Chlamydia?
Azithromycin
or
Doxycycline
- Contact trace partners
- Doctor must be notified
- Test of cure 4-6 weeks (If too early may still have trade DNA for up to 3 weeks)
- Advise retset in 3 months
What are the features of Trichomonas vaginalis ?
- Flagellated protozoan
- Frequently asymptomatic (67% asymptomatic) - Males more likely to be asymptomatic
- Frothy, green-yellow vaginal discharge
- ph >5.0
- Cervical erythema & friability
- Pruritis, dysuria, abdominal pain
- Prevalence underestimated
- Marker for high risk sexual activity
- Genital inflammation –> Increase risk for HIV acquisition
- Associated with
- Non-steady partner/Older partner
- Marijuana use
- High in Indegenous community
What laboratory testing can be done to test for Trichomonas vagnalis?
- High vaginal swab
- Wet prep, microscopy - motile
- Culture
- Urine - PCR
- Sometimes seen on PAP smear
What are the treatments for Trichomonas vaginalis?
Metronidazole 2g oral single dose
Tinidazole 2m oral single dose
Metronidazole 400mg
Clindamycin cream
What are the stages of Treponema palladium (syphilis) infection?
Primary
- Initial infection
- Painless ulcer at site of inoculation
- Takes 3 weeks, because bacteria takes a long time to replicate (33 hr)
- This will heal up
Secondary
- 6-12 weeks later you get secondary symptoms
- Spread via lymphatic
- Generate rash, alopecia, hepatitis, generalized lymphadenopathy
- Eventually heal
Tertiary
- If untreated organism stays for life and lead to damage of varous organs
- Gumma - inflammatory reaction that can destroy joint, skin, aorta (aortitis), takes decades to develop
- So you want to identify people at primary, secondary and tertiary.
What are the laboratory detection test for Syphilis (T. Palladium)
- Microscopy
- Dark field
- Serology
- Non-treponemal test (VLRL, RPR)
- Treponemal test (TPHA, EIHA, FTA-Abs)
What is the non-treponemal test (VLRL, RPR) test for T.Palladium testing?
- Antibodies to cellular lipids & lecithin (non-specific antigen)
- Positive 4-8 weeks post infection
- 70% positive within 2 weeks of chancre (painless ulcer)
- 100% positive for secondary & latent infection
- Useful for screening/monitoring therapy
- Non-specific antibodies gradually disapere if respond to treament
- Titrate to detect response to treatment
- False positive reaction
- CT disorder, viral infection (hepatitis, vaericella, EBV, measles) IVDU 10%, pregnancy
- False negativ reaction
- Prozone effect
What is the treponemal test eg. EIA, TPHA, TPPA, FTA-Abs testing?
- Positive slightly earlier
- If RPR is also present it indicates persistent infection
- positive for life
- Immunoglotting and PCR
What are the features of Mycoplasma genitalium?
Slow growing, takes 2m to grow in culture.
Mycoplasma deform in shape and don’t have a cell wall. So can’t gram stain.
They form flask shape, pertuberanece is what they use to attach to columnar epithelium which they use to enter the cell.
Antibiotic resistant
Prevalence 3-5%
What does Mycoplasma genitalium cause?
- Urethritis in men
- Cervicitis in women
- Acute endometritis
- PID post termination of pregnancy
- Presists for 3-6 months
- Preterm delivery
- May presispose to HIV transmission
What is the treatment for Mycoplasma genitalium?
- Azithromycin 1gm
- 85% efficacy
- Moxifloxacin 400mg daily 7-10 days
- Expensive
What are the indications for STI testing?
- Symptomatic patient investigation
- Screening asymptomatic infeciton
- Pre-pregnancy
- Antenatal screening
- Blood and organ donation
- Contact tracing
- Epidemiological surveillance
