Title : Patterns of chlamydia trachomatis and neisseria gonorrhoeae in different anatomical sites among pre-exposure prophylaxis (prpe) users in Brazil
Introduction: The presence of an untreated STI significantly increases the chance of acquiring HIV. In Brazil, CT/NG testing among PrEP users is insufficient and syndromic treatment is a priority in clinical practice. Multi-site testing for CT/NG improves screening of asymptomatic cases and timely treatment. So, it’s essential for HIV prevention.
Objective: This study aimed to test the importance of multisite testing for better screening of these pathogens and to test the presence of symptoms as an indicator for CT/NG infection.
Methods: This is a cross-sectional study carried out in four public infectious diseases clinics in the city of Ribeirão Preto, São Paulo, Brazil between January 2022 and March 2023. All participants had an anal swab and a first-pass or mid-stream urine collected for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) analysis by Polymerase chain reaction (PCR). Data about sociodemographic, sexual behavioural and clinical aspects were collected. Pathway analysis was used to examine the direct and indirect relationships between variables according to the theoretical model.
Results: We screened 171 PrEP users which had two samples collected (urine and anal swab), resulting in 342 samples. Comparing the anatomic sites, the urine samples showed lower sensitivity for CT and NG than anal samples. Gonorrhoea was directly linked to lower age (β= -0.161, p=0.001). Time of PrEP use was directly associated with CT infection (β=0.202; p=0.042) and inversely associated with dysuria (β= -0.121, p=0.009). Lower occurrence of yellow-green secretion was linked to the detection of CT (β= -0.089, p=0.005) and NG (β= -0.048, p=0.002) infections. Foul-smelling discharge was directly associated with CT (β= 0.275, p=0.004) and NG (β= 0.295, p= 0.037) infection.
Conclusion: The symptoms are a bad indicator of CT and NG infection, and the screening must be done in multiple sites since most of the positive results would be missed if only urines were tested. In the case of testing only one anatomical site, specifically the urethra, the CT/NG incidence and prevalence would be underestimated. Multisite testing improves detection rates of CT/NG, and PrEP follow-up benefits people offering STI testing.
Descriptors: Chlamydia trachomatis; Neisseria gonorrhoeae; Sexually Transmitted Infections; Prevalence; Pre-Exposure Prophylaxis; HIV prevention;
Our findings call the attention of health authorities supporting their decisions over public health policies focused on offering CT/NG testing. Our study is about the prevalence of CT/NG by multi-site testing in PrEP users and about the symptoms as a bad indicator of CT/NG infections. This will help the audience understand that multisite testing improves the chance of detecting pathogens. Further, our evidence contributes to the discussion about reducing syndromic diagnosis. Finally, it contributes to the discussion that PrEP benefits their users because it makes it easier to access STI testing, early diagnosis and quick treatment.