Asymptomatic extragenital Neisseria gonorrhoeae infection among transgender women in Argentina: Prevalence, antimicrobial susceptibility, and molecular characterization

Background Asymptomatic extragenital Neisseria gonorrhoeae (NG) infection contributes to ongoing transmission and may facilitate the emergence of antimicrobial resistance. This study aimed to determine NG prevalence, antimicrobial susceptibility patterns, and sequence types among transgender women (TGW). Methods Real-time PCR (qPCR) and culture for NG were performed on pharyngeal and rectal swabs and first-void urine (FVU) samples from TGW attending Fundación Huésped in Buenos Aires, Argentina (August 2021-March 2022). Quantification cycle (Cq) values from qPCR-positive samples were used as a proxy for bacterial load. Culture-positive isolates underwent antimicrobial susceptibility testing and NG multi-antigen sequence typing (NG-MAST). Participants were also tested for other sexually transmitted infections (STI) and sociodemographic and behavioral data were collected by questionnaire. Results We included 117 TGW: median age 32 (IQR 29-39), 55% had not completed high school, 54% were currently engaged in sex work, 55% had ≥ 5 sexual partners in the last month, and 68% reported recreational substance use in the previous year. At baseline, 46% were living with HIV, 20% had active syphilis, and 6% extragenital chlamydia. Global NG prevalence (determined by positive qPCR) was 9% (10/117) with 9 rectal infections (8%; 9/116), one pharyngeal infection (1%; 1/117), and none detected in FVU. Only three of nine PCR-positive rectal samples yielded a positive culture. All isolates were susceptible to ceftriaxone and azithromycin and showed intermediate susceptibility or resistance to tetracycline. Sequence types (ST) were ST21119, ST8202, and ST21122. No associations were found between asymptomatic extragenital NG infection and sociodemographic/behavioral factors. Seventy percent of positive PCR samples had a Cq ≥ 28, suggesting lower bacterial loads. Conclusion Asymptomatic extragenital NG infection prevalence among TGW in Buenos Aires was 9%, with no infections detected in FVU, underscoring the importance of extragenital screening. Limited culture recovery highlights the potential value of complementary approaches to antimicrobial resistance surveillance.