The link between contraceptive methods and Chlamydia trachomatis infection

The effect of various contraceptive methods on Chlamydia trachomatis (CT) infection was examined in a group of 158 women, with a mean age of 26.9 years, patients of a family planning clinic. Their symptoms were mild abdominal pain or vaginal discharge. Antibodies to CT were examined by an indirect immunoperoxidase assay, with a commercial kit. From each patient a vaginal smear was collected for bacteriologic and mycologic study. In group I, consisting of 30 married women with a mean age of 31 years, 5 (16.7%) IUD users had a positive test for CT antibodies. In group II, comprising 57 women, with a mean age of 23.3 years, 22 (38.6%) oral contraceptive (OC) users, of whom 94.7% were unmarried, had positive tests for CT antibodies. The difference between these two groups was statistically significant (p<0.05). In group III, comprising 71 women with a mean age of 28.1 years, 62% unmarried and using other contraceptive methods, 15 (21.1%) had a positive test for CT antibodies. The incidence of CT infection was not different in the 3 groups under study, when the factors of age and marital status were taken into consideration (p>0.30). Bacterial vaginal infection was found in 43.3% of the IUD users, compared with only 14% of the OC users (p<0.01). In contrast, in the OC users, candidiasis was predominant, the difference from the other groups being statistically significant (p<0.001). The women with positive antibodies also more frequently had colonies of bacterial and mycological vaginal infection. CT infection is a sexually transmitted disease (STD) related to a specific and non-monogamous sexual life style. The unmarried women in the group of OC users are the most at risk, taking into consideration that they begin sexual life at an early age and that they often change their partners.