Chlamydia trachomatis Infection

Chlamydia is one of the commonest bacterial sexually-transmitted infections (STIs), and is also one of the commonest preventable causes of secondary infertility. Chronic pelvic pain and increased risk of ectopic pregnancy are other serious consequences for women. Newborns exposed to C. trachomatis during childbirth are at increased risk of contracting conjunctivitis, bronchiolitis, and pneumonia.

Heaped-up oedema on colposcopy often described as 'cobblestone oedema' (see pictures) is usually caused by C. trachomatis infection, but the presence of this infection may not lead to any particular signs. Given that Chlamydia is often asymptomatic, the only way to reduce the prevalence of this infection is through screening. The commonly-used tests are culture (55% sensitive for cervical swab), enzyme immunoassay [78% sensitive for cervical swab; 37% sensitive for first void urine (FVU) sample], and nucleic acid amplication (Ligase chain reaction test is 96% sensitive for FVU).

The United States Centre for Disease Control recommends¹ screening all men and women who are sexually-active and under 25 years of age, those who have changed partners within the last 3 months, and those whose partner complains of symptoms or is found to be infected.

In addition, it is important to screen all women in the following groups:

• Those who are pregnant (cervical infection may be more likely).
  
  
• Those affected by 'breakthrough' bleeding while on oral contraceptive pills.
  
  
• Those undergoing manipulation of their cervix (e.g. prior to insertion of an intrauterine device, termination of pregnancy, or dilatation and curettage).
  

Effective treatment and contact-tracing are equally important; along with screening, they are useful in controlling Chlamydia. Treatment is with a 1-week course of tetracylines or a stat. dose of the long-acting erythromycin, azithromycin. If a pregnant woman needs treatment, then it is advisable to prescribe erythromycin for 1 week, as this is least harmful to the baby.

Advice about condom use and not changing partners is important in terms of primary prevention.

Reference

1. Centres for Disease Control and Prevention. Recommendations for the prevention and management of Chlamydia trachomatis infections 1993. MMWR Morb Mortal Wkly Rep 1993;44(RR-12):1-39.