Objective: To evaluate how common pharyngeal Chlamydia trachomatis (CT) is among mainly heterosexual women and men with a confirmed or a highly suspicious genital infection having had recent unprotected active oral sex.
Design: Prospective observational study.
Setting: Out-patient clinics for sexually transmitted infections in Stockholm.
Population: A total of 143 women and 138 men with a confirmed or suspected genital CT infection and a history of active oral sex.
Methods: Pharyngeal samples from men and women in the study population were analyzed for the presence of CT.
Main outcome measures: Number of positive CT in pharyngeal samples in relation to positive CT in genital samples.
Results: Of the women, 9/128 (7.0%) were positive in the pharyngeal samples. None were exclusively positive in the pharynx. Three of 110 men (2.7%) had pharyngeal involvement. One man was positive in the pharynx as well as in the urine sample, and two men were exclusively pharyngeal CT positive.
Conclusions: The finding of CT in the pharynx is not common in spite of the presence of a genital infection and a history of active oral sex.