G-3033

Seroprevalence of Anti-HBs Antibodies among Female Sex Workers in Fars province, Iran, 2023-2024

 Negar Nayerain Jazi ¹ ℗, Seyed Mohammad Ali Hashemi ², Sajad Alavimanesh ³, Abolfazl Gheshlaghi ², Jamal Sarvari ² ©   

 
Abstract

Introduction: Hepatitis B virus (HBV) is a long-recognised occupational hazard for female sex workers (FSWs) because of frequent exposure to body fluids and the absence of mandatory adult boosters. We therefore quantified anti-HBs antibody (anti-HBsAb) titres in FSWs across Fars Province and analysed sociodemographic and behavioural correlates of protective immunity. Materials and Methods: In this cross-sectional study, 206 FSWs presenting to outreach clinics in Shiraz and Marvdasht (2023 –2024) were recruited by convenience sampling. Five millilitres of venous blood were collected, centrifuged, and the separated sera stored at –20 °C until analysis. Anti-HBsAb titres were measured with a commercial ELISA kit (DiaPro, Italy); titres ≥ 10 mIU mL⁻¹ were deemed protective. Demographic, social and behavioural variables—including age, education, income, condom use, partner/client numbers, substance use and sexually transmitted infection (STI) history—were captured by structured interview. Associations were tested with χ² or linear-by-linear trend in SPSS v26; p 0.05 signified significance. Results: Valid serology was obtained from 202 women (mean ± SD age 42.3 ± 9.7 years, range 17–68). The Mean Anti-HBsAb titre was 45.3 ± 84.1 mIU mL⁻¹ (median 0 mIU mL⁻¹). Only 70/202 participants (34.7 %) had protective titres (10–100 mIU mL⁻¹: n = 38; 100 mIU mL⁻¹: n = 32), whereas 132/202 (65.3 %) were unprotected, including 46 who were completely seronegative. A significant positive linear trend was observed for condom use: women reporting more consistent use were more likely to be immune (trend χ² = 7.59, p = 0.006), although the overall five-level χ² narrowly missed conventional significance (χ² = 20.17, df = 12, p = 0.064). No significant association emerged between antibody status and age group, marital status, literacy level, income, partner/client numbers, STI history, drug use, syringe sharing, imprisonment, alcohol consumption or tattooing (all p 0.15). Discussion and Conclusion: Nearly two-thirds of FSWs in Fars Province lacked serological protection against HBV, despite three decades of universal infant mmunization, highlighting waning immunity and gaps in adult booster coverage. The absence of associations with age and most risk factors suggests uniformly low booster coverage across subgroups, while the positive trend with condom use may reflect greater health-seeking behaviour among consistent condom users. Routine anti-HbsAb screening, counselling and free booster vaccination should be integrated into sexual-health and harm-reduction services to close this immunity gap and curb onward HBV transmission in a key population.

Keywords: Anti-HBsAb; Female sex workers; Fars province; Iran