Phthirus pubis as a predictor for Chlamydia infections in adolescents

Background: Providers not skilled in the evaluation of sexually transmitted infections (STIs) may treat pubic lice infestation without considering other organisms. This study compared the rate of chlamydia and gonorrhea infections in adolescents with and without pubic lice. Goal: The goals of the study were to compare the rate of chlamydia and gonorrhea infections between adolescents infested or not infested with pubic lice and to evaluate lice infestation as a predictor for concurrent chlamydia or gonorrhea infection. Study Design: A retrospective chart review of sexually active adolescents at a juvenile detention center in the Midwest between July 1998 and June 2000 was conducted. The index group was 62 adolescents with pubic lice screened for concurrent STIs. The control group included 201 randomly selected adolescents without pubic lice who underwent STI screening. Results: In the entire study population (263 subjects), there were 60 cases of chlamydia (23% of all subjects) and 29 cases of gonorrhea (11%). Neisseria gonorrhoeae infection was present in 18% of index subjects and 9% of controls. Chlamydia trachomatis infection was noted in 39 % of index subjects and 18% of controls. Pubic lice infestation predicted C trachomatis infection (odds ratio = 3.31). Conclusions: Pubic lice infestation is predictive of a concurrent C trachomatis infection in this population. Adolescents infested with pubic lice should be screened for other STIs, including chlamydia and gonorrhea.