Pharyngeal Chlamydia trachomatis is not uncommon any more.

Background: The significance of Chlamydia trachomatis (Ct) infection in the pharynx, and possible symptoms, are under discussion. Most studies have involved only homo/bisexual men. We report findings of pharyngeal Ct (PhCt) infections in patients with long-lasting throat discomfort and the prevalence of PhCt in genitally Ct-infected young people in a Swedish primary care setting.

Method: Sub-study 1 (SS1) included 48 persons aged 15-35 y, with pharyngeal discomfort for more than 14 days. Sub-study 2 (SS2) included 150 persons, aged 15-35 y, with genital Ct. Questionnaires concerning symptoms, sexual behaviour and sexual identity were completed for both groups. Samples for Ct testing were taken from the pharynx, and in SS1, samples were also collected to ascertain genital Ct.

Results: In SS1, 2 of 48 persons (4%) with pharyngeal discomfort had PhCt. In all, 35 of the 48 persons (73%) included in SS1 reported unprotected oral sex during the previous year. In SS2, 11 of 92 women (12%) and 4 of 58 men (7%) tested positive for PhCt. More women (94%) than men (83%) had given unprotected oral sex. Persons with PhCt had more symptoms from the upper respiratory tract (p = 0.04).

Conclusions: Some primary care patients with long-lasting throat discomfort have a PhCt infection. PhCt infection is not uncommon in genitally infected sexually active people. More heterosexual women than heterosexual men had given unprotected oral sex and were infected by Ct in the pharynx. Thus, research on PhCt should not focus on homo/bisexual men only. Information about Ct should include the risk of contracting a PhCt infection as well as a gender perspective.