STIs Flashcards
Initiation of sexual activity
2/3 girls before 18
20% have not had intercourse at 20
70% boys before 18
Pelvic exam of teenage girl
rehearsal, demystify
omit rectal exam
Indications: medical evaluation of specific symptoms
- abdominal or pelvic pain
- concern about retained tampon, condom
Non-indications: asymptomatic screening for GC/CT (urine/self swabs equally sensitive)
Contraindications for pelvic exam in a teenage girl
prepubertal status
prior to onset of sexual activity
refusal of teen
parent’s desire to establish virginity
Behavioural risk of STIs in adolescence
30% of adolescent females have first sexual experience with male partner >5 y older
Repeat STI acquisition is HIV risk factor
chlamydia etc can have lifelong impacts on fertility
Gonorrhea clinical spectrum
local - urethral, cervical, rectal, pharyngeal
PID
tubo-ovarian abscess: can cause infertility
Perihepatitis: systemic
Dissemination: skin
Arthritis
Perinatal
Gonorrhea Dx
5-10% males asymptomatic
Culture: fastidious organism, require high CO2 content, required for all child abuse/forensic studies
Gram stain: high specificity, neturophil with diplococci - if see intracellular pink (gram-) diplococci on urethral smear, diagnostic for gonorrhea
NAAT: high sensitivity/spec, available for urine, excellent for most clinical uses
Antimicrobial susceptibility of N. gonorrhea
~25% resistant to penicillin or tetracycline or both
fluoroquinolone resistance disseminated throughout the world
0.5% show decreased susceptibility to azithromycin
sporadic cases of decreased susceptibility to ceftriazone and cefixime
Tx of uncomplicated gonococcal infections of cervix, urethra, rectum
Ceftriaxone 250 mg im once PLUS
azithromycin 1g orally once
OR doxycycline 100mg orally BID for 7 days
Chlamydia etiology
most common reportable infection in NA
cases in Canada increasing
annually cost 50-120 mil
BC: adolescents have chlamydia rates second highest to young adults
most common infection associate with infertility
Clinical spectrum of chlamydia
Local: urethral, cervical, epididymitis (rare); discharge more subtle than gonorrhea PID tubo-ovarian abscess Reiter syndrome Pre-hepatitis Perinatal transmission: incubation 3-6 w
Dx chlamydia
> 80% in males/females are asymptomatic
Culture: high specificity, variable sensitivity, required for all child abuse evaluations
NAAT: high spec/sens, useful, urine testing
PID
spread of microorganism from vagina/cervix to endometrium, fallopian tubes, and ovaries
Incidence/prevalence of PID
1 mil US women annually
No surveillance/reporting requirements
more likely to be diagnosed in ambulatory settings
PID and adolescents
33% of PID
women younger than 25 account for 70% of cases
younger women vulnerable because of transformation zone
history of PID - risk factor for future PID
multiple partners - increase risk
- OCP - decrease risk
Minimum criteria in the Dx of PID
Uterine tenderness
Adnexal tenderness
Cervical motion tenderness –> very important!!!
Additional criteria for Dx of PID
increase specificity
Temperature >38.3
abnormal cervical/vaginal mucopurulent discharge
presence of abundant numbers of WBC on vaginal secretions
elevated ESR, CRP
gonorrhea/chlamydia +
Microbial etiology of PID
most commonly:
N gonorrhea 30-80%
C trachomatis - 20-40%
Both - 25-75%
Sequelae of PID
25% of single episode PID experience ectopic pregnancy, infertility or chronic pelvic pain Tubal infertility after PID; - 8% after 1st episode 20% after 2 50% after 3
Tx guideline for PID in adolescents
low threshold of suspicion treat empirically as early as possible laparoscopy/US should not delay empiric treatment Hospitalize for: -inability to follow oral regimen - vomiting -pregnancy - abscess - tx failure
Syphilis pathology
penetration:
- T pallidum enters body via skin and mucous membranes through abrasions during sexual contact
- transmitted transplacentally from motehr to fetus during pregnancy
Dissemination:
- travels via lymphatic system to regional lymph nodes and then throughout body via blood stream
invasion of CNS can occur at any time
Primary syphilis
Primary lesion, chancre at site of inoculation
Macule–>papule–>ulcer
typically painless, indurated, clean base
Highly infectious
heals spontaneously within 1-6 wks
25% with multiple lesions
Regional lymphadenopathy - rubbery, painless, bilateral
Serologic testing may not be positive at this stage
2ndary syphilis
3-6 wks after primary chancre, may persist for weeks-mo primary and secondary may overlap mucocutaneous lesions most common manifestations: rash (75-100%) papulosquamous? palmar, plantar Lymphadenopathy: 50-86% Malaise Mucous patches 6-30% Condylomata lata 10-20% Alopecia 5%
Serologic tests usually highest in titer
Latent syphilis
host suppresses infection –> no lesions clinically apparent
only evidence is positive serology
may occur btw primary /2ndary stages, etc.
Categories:
Early latent: less than 1 yr
Late latent: >=1 yr
Neurosyphilis
occurs when T pallidum invades CNS
may occur at any stage of syphilis
can be asymptomatic
Early: few mo- few years after infectino
- acute syphilitic meningitis, meningovascular syphilis, ocular involvement
Late: decades after infection, rarely seen
- general paresis, tabes dorsalis, ocular involvement
Serologic tests for syphilis
Treponemal (qualitative) FTA-ABS
NOntreponemal (qualitative/quantitative) RPR and VDRL
using only one type insufficient for Dx
Therapy for syphilis
Benzathine penicillin G 2.4 mil units IM in a single dose No resistance to penicillin if allergic: doxycycline 100 mg po BID x 14 or tetracycline 500mg po QID x 14
