Integration of GeneXpert CT/NG and OSOM Trichomonas testing into STI management in an adolescent clinic in Harare, Zimbabwe: a cross-sectional study.

ABSTRACT:

OBJECTIVE: To assess whether integrating aetiological sexually transmitted infection (STI) testing into routine adolescent care improves diagnostic and clinical performance compared with syndromic management alone in Harare, Zimbabwe.

DESIGN: Cross-sectional study.

SETTING: Mbare Adolescent clinic.

PARTICIPANTS: 402 sexually active adolescents aged 16–19 years were consecutively enrolled (September 2023–June 2024).

METHODS: Standardised assessment included history, examination and routine HIV/syphilis screening. Vaginal/endocervical swabs (females) and urine (males) were tested for (CT), (NG) and (TV) using GeneXpert CT/NG and OSOM Trichomonas rapid testing. Syndromic treatment followed national guidelines. We assessed laboratory results among participants receiving syndromic treatment and infections detected through aetiological screening among those not receiving syndromic treatment, stratified by pathogen and sex.

RESULTS: Among participants (median age 18 years; 49.8% female), 153/402 (38%) had an STI-related syndrome. Syndromic management led to treatment targeting CT in 182/402 (45%), NG in 176/402 (44%) and TV in 83/402 (21%) participants. Aetiological testing detected CT in 80/402 participants (20%)—65/200 (33%) females and 15/202 (7%) males—and NG in 73/402 (18%)—44/200 (22%) females and 29/202 (14%) males; TV was detected in 35/200 (18%) females and 1/202 (1%) males. Among participants receiving syndromic treatment, 44/106 (42%) females and 12/42 (29%) males tested negative for all pathogens assessed. Pathogen-specific negative results among treated females were observed for CT in 73/104 (70%), NG in 70/101 (69%) and TV in 56/77 (73%); among treated males, the corresponding proportions were 31/42 (74%) for CT and 14/42 (33%) for NG. Among participants not receiving syndromic treatment, CT was detected in 28/79 (35%), NG in 8/79 (10%) and TV in 3/84 (4%) females, and CT in 4/134 (3%) and NG in 1/137 (1%) males.

CONCLUSIONS: STIs were frequently detected among adolescents attending primary care, including among those without symptoms. Among symptomatic participants receiving syndromic treatment, aetiological testing identified discordance between treatment and laboratory findings while screening identified infections among participants not receiving syndromic treatment. Integrating aetiological testing into adolescent services could complement syndromic management by supporting more targeted treatment and detection of asymptomatic infections.