Alarming incidence of reinfections after treatment for Chlamydia trachomatis and gonorrhoea: Can we predict and prevent them?

Abstract

Background: Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections are a public health problem, worsened by frequent reinfections, whose incidence rate is not known in Spain. The objective of this study is to estimate in patients diagnosed with NG, CT or mixed infection (NG and CT): (1) the incidence of reinfections by the same microorganism, (2) the total incidence of Sexually Transmitted Infections (STI), both by the same microorganism and by infections other than the initial one, and (3) to identify predictors of reinfection.

Methods: Observational prospective case series involving 986 patients with CT and/or NG at specialized STI clinics in Biscay (Spain) between 2016 and 2019.

Results: The six month cumulative incidence of reinfection by the same microorganism was 17.24% (CI95%: 14.9-19.7) and 24.65% (CI95%: 21.9-27.4) for any STI (reinfection or other). Being an immigrant (OR=1.8; CI95%: 1.3-2.6), men who have sex with men (OR=1.8; CI95%: 1.3-2.6), number of sexual partners (OR=4.3; CI95%: 2.7-6.8 for more than 5 partners), having a new partner (OR=1.7; CI95%: 1.08-2.6), not always using a condom (OR=1.4; CI95%: 1.02-1.9) and consumption of alcohol prior to sex (OR=3.8; CI95%: 1.5-9.5) were associated with reinfection by any STI.

Conclusion: These characteristics allow doctors to identify patients in whom to prioritize short-term rescreening for repeated infections with any STIs after initial treatment for NG or CT.

Keywords: Chlamydia trachomatis; Factores de riesgo; Gonorrhoea; Infecciones de transmisión sexual; Neisseria gonorrhoeae; Reinfección; Reinfection; Risk factors; Sexually transmitted infections.