Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) coinfections are commonly reported; in high-risk groups up to 40% of those infected with NG are also infected with CT.1 While coinfections might happen accidentally, it has been mathematically proven that it occurs much more frequently than can be expected from random chance alone.2 However, little is known about the effect of coinfections on pathogenesis, bacterial load, transmission and disease severity. Prior studies in this field are scarce and with contradictory results.1 To address this knowledge gap we looked at the effect of NG/CT coinfections on the NG bacterial load, and how coinfections with CT influence symptom severity of NG infections.

To test this, we assessed the bacterial load and symptoms in all NG-positive samples of patients visiting the South Limburg STI clinic in the Netherlands between January 2012 and January 2022. These 3226 NG-positive samples consisted of 1175 anorectal swabs (88% male), 1014 oropharyngeal swabs (82% male), 688 male urine and 349 female vaginal swabs (table 1). CT coinfections occurred in 16.8% (table 1).

Bacterial NG load in NG+/CT- samples (n=2683) and …