[Prevalence and treatment of pharyngeal Chlamydia trachomatis infections]

In recent years, the number of the patients with pharyngeal infection caused by Chlamydia trachomatis is believed to be on the rise due to diversification in sexual behaviors. In addition, pharyngeal infection by C. trachomatis is often asymptomatic, and this is also believed to be a major factor for the increase of the disease. In this study, we conducted a survey among general females and commercial sex workers (CSWs) to study their sexual behavior and prevalence of chlamydial infections (in uterine cervix and pharynx). The results showed that orogenital contact has become a common act, even for general females. Chlamydial infections of uterine cervix were found in 33.3% and 7.9% of CSWs and general females, respectively. Chlamydial infections of pharynx were found in 22.5% and 5.2% of CSWs and general females, respectively. The evaluation of treatments of these infections with clarithromycin, levofloxacin, and azithromycin showed that 7, 10, and 14 days administrations of 400 mg clarithromycin, 7, 10, and 14 days administrations of 300 mg levofloxacin, and a single dose of 1000 mg of azithromycin, would eradicate 100% of C. trachomatis for infections of uterine cervix. For pharyngeal infections, 10 and 14 days administrations of clarithromycin and levofloxacin were shown to eradicate 100% of C. trachomatis. However, the eradication rates for 7 days administrations of clarithromycin and levofloxacin were 83.9% and 86.2%, respectively, and the rate for a single dose of azithromycin was 85.0%. From these results, it was thought that more than 10 days of administrations of clarithromycin or fluoroquinolone antibacterial agents such as levofloxacin are necessary to treat pharyngeal chlamydial infection. Clinical significance of pharyngeal chlamydial infection is still not clear; however, this study have shown the need for more detailed investigations using culture assay, in corporation with doctors in otolaryngology and internal medicine.