Epidemiology and therapy of Chlamydia trachomatis infections

Chlamydia trachomatis infections are exceedingly prevalent, and can be associated with significant sequelae. The major infections are urethritis, cervicitis, salpingitis, and ocular infection. Chlamydial genital infections present as syndromes, where C. trachomatis is one of the causes of the syndrome. Because specific laboratory diagnosis of a chlamydial infection is often not available, and even if available does not exclude the concurrent presence of other pathogens, therapy should usually be directed at all the major causes of the syndrome. Thus, although C. trachomatis is readily eradicated by tetracyclines, macrolides, sulphonamides, and rifampicin, for most situations tetracyclines are the drugs of choice. Penicillins have some activity when used in multiple-dose therapy, but are not reliable for eradication of chlamydiae. Aminoglycosides, nitroimidazoles, and the newer cephalosporins have minimal or no useful activity. Seven days of tetracycline hydrochloride 500mg 4 times daily or doxycycline 100mg twice daily are the optimum regimens for uncomplicated urethritis, cervicitis (except in pregnancy), and gonorrhoea. These regimens should be extended to 10 days for epididymitis and salpingitis. Additional antimicrobials should be added to the salpingitis regimen. For chlamydial infection during pregnancy, erythromycin 500mg 4 times daily for 1 week or 250mg 4 times daily for 2 weeks should be utilised. Neonatal infection requires 2 to 3 weeks of systemic treatment with erythromycin. Inclusion conjunctivitis responds well to antimicrobials, but improved sanitation has a greater effect than antimicrobial therapy in the management of trachoma.