Chlamydia

Question 1

Chlamydia - epi

Answer 1

1. Chlamydia trachomatis = obligate intracellular bacterium
2. Types A-C cause endemic eye infection (social transmission rather than sexual); types D-K are responsible for common urogenital infections
3. Urogenital chlamydia = most common bacterial STI in most industrialised countries
4. True figure estimated to be 200,000 - 300,000 cases annually in Australia (probably 4-5x more infections than notifications)
5. Risk of infection highest in those

Question 2

Chlamydia - symptoms

Answer 2

Completely asymptomatic in 70-90% of women and 50% of men. Most of those infected acquire the infection from an asymptomatic partner. When symptoms do occur, they usually appear 1-3 weeks after exposure

In males - urethritis is the most common symptom

Women may develop any combination of the following symptoms:

1. Dysuria
2. Increased vaginal discharge
3. Dyspareunia
4. Post-coital bleeding
5. Lower abdominal pain

Question 3

Chlamydia - complications

Answer 3

Women

1. PID
2. Ectopic pregnancy
3. Infertility

Males
4. Reactive arthritis (large joint arthritis + inflammation of the uvea + genital symptoms

5. Vertical transmission from mother to infant
   - May occur during vaginal delivery
   - About 25% of infected neonates present with chlamydial conjunctivitis and 15% will develop respiratory infection

Question 4

Chlamydia - ix (3)

Answer 4

1. Gold standard = nucleic acid amplification tests (NAAT), such as PCR (polymerase chain reaction)
   - In males: first-pass urine sample (one taken more than 2hrs since the bladder was last emptied) is considered the diagnostic test of choice
   - In females: cervical swab provides the most sensitive test. Urine testing and self-collected vaginal swabs are slightly less sensitive and avoid the need for a speculum examination - preferred for screening
2. Note - samples from sites other than the cervix, vagina and urine should be interpreted with caution (e.g. rectum, pharynx)
3. Sexual history may also indicate the need for further STI testing

Question 5

Chlamydia - tx

Answer 5

1. Uncomplicated infections in both males and females = azithromycin 1g orally as single dose (use permitted during pregnancy)
2. Doxycycline 100mg BD for 7d can be used in the rare case of azithromycin allergy, but should not be used in pregnancy
3. For infections complicated by PID, epididymitis or reactive arthritis, a longer course of abx is required
4. All current sexual partners of a pt with proven chlamydia should receive standard tx for chlamydia after appropriate swabs have been obtained. Sexual contact should be avoided for 1 week after tx
5. Pts diagnosed with chlamydia should contact all previous partners over the past 6mo so that they too may seek testing and advice. Notifiable disease. Test of cure not routinely performed but further test 2-3mo after tx advised, as rate of reinfection may be up to 20%