Abstract
The incidence of new infections with C trachomatis was found to be 19%. Predisposing factors for a subsequent chlamydial infection were multiple partners, smoking and previous infection with C trachomatis. Girls with a spread cervical ectopy were not more likely to contract a chlamydial infection in one year than girls without an ectopy. Oral contraceptive use was not found to predispose for a chlamydial infection.