STIs

Question 1

Initiation of sexual activity

Answer 1

2/3 girls before 18
20% have not had intercourse at 20
70% boys before 18

Question 2

Pelvic exam of teenage girl

Answer 2

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)

Question 3

Contraindications for pelvic exam in a teenage girl

Answer 3

prepubertal status
prior to onset of sexual activity
refusal of teen
parent’s desire to establish virginity

Question 4

Behavioural risk of STIs in adolescence

Answer 4

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

Question 5

Gonorrhea clinical spectrum

Answer 5

local - urethral, cervical, rectal, pharyngeal
PID
tubo-ovarian abscess: can cause infertility
Perihepatitis: systemic
Dissemination: skin
Arthritis
Perinatal

Question 6

Gonorrhea Dx

Answer 6

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

Question 7

Antimicrobial susceptibility of N. gonorrhea

Answer 7

~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

Question 8

Tx of uncomplicated gonococcal infections of cervix, urethra, rectum

Answer 8

Ceftriaxone 250 mg im once PLUS
azithromycin 1g orally once
OR doxycycline 100mg orally BID for 7 days

Question 9

Chlamydia etiology

Answer 9

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

Question 10

Clinical spectrum of chlamydia

Answer 10

Local: urethral, cervical, epididymitis (rare); discharge more subtle than gonorrhea
PID
tubo-ovarian abscess
Reiter syndrome
Pre-hepatitis
Perinatal transmission: incubation 3-6 w

Question 11

Dx chlamydia

Answer 11

> 80% in males/females are asymptomatic
Culture: high specificity, variable sensitivity, required for all child abuse evaluations
NAAT: high spec/sens, useful, urine testing

Question 12

PID

Answer 12

spread of microorganism from vagina/cervix to endometrium, fallopian tubes, and ovaries

Question 13

Incidence/prevalence of PID

Answer 13

1 mil US women annually
No surveillance/reporting requirements
more likely to be diagnosed in ambulatory settings

Question 14

PID and adolescents

Answer 14

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

Question 15

Minimum criteria in the Dx of PID

Answer 15

Uterine tenderness
Adnexal tenderness
Cervical motion tenderness –> very important!!!

Question 16

Additional criteria for Dx of PID

Answer 16

increase specificity
Temperature >38.3
abnormal cervical/vaginal mucopurulent discharge
presence of abundant numbers of WBC on vaginal secretions
elevated ESR, CRP
gonorrhea/chlamydia +

Question 17

Microbial etiology of PID

Answer 17

most commonly:
N gonorrhea 30-80%
C trachomatis - 20-40%
Both - 25-75%

Question 18

Sequelae of PID

Answer 18

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

Question 19

Tx guideline for PID in adolescents

Answer 19

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

Question 20

Syphilis pathology

Answer 20

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

Question 21

Primary syphilis

Answer 21

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

Question 22

2ndary syphilis

Answer 22

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

Question 23

Latent syphilis

Answer 23

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

Question 24

Neurosyphilis

Answer 24

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

Question 25

Serologic tests for syphilis

Answer 25

Treponemal (qualitative) FTA-ABS
NOntreponemal (qualitative/quantitative) RPR and VDRL
using only one type insufficient for Dx

Question 26

Therapy for syphilis

Answer 26

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