A simulated patient study of antibiotic utilization within the informal healthcare sector for pediatric viral infections in Adamawa State, Nigeria

Antimicrobial resistance (AMR) is a leading cause of mortality in Sub-Saharan Africa, with Nigeria bearing a significant burden. The informal medicine retail sector operates largely outside national antimicrobial stewardship frameworks, yet the extent of inappropriate antibiotic dispensing for pediatric illnesses remains poorly quantified. We conducted a cross-sectional study using simulated patient methodology in 315 Patent and Proprietary Medicine Vendor shops across 10 Local Government Areas in Adamawa State, Nigeria (June–December 2025). Trained actors presented a standardized scenario of a 3-year-old child with viral infection symptoms (dry cough, low-grade fever) using a three-level escalation protocol. Dispensed antibiotics were classified using WHO AWaRe criteria and analyzed using multivariate logistic regression. Of the 315 outlets visited, 78.4% were Patent and Proprietary Medicine Vendor (PPMV) operated, 53.7% were male-operated, and 45.4% of vendors had more than 10 years of practice experience. Antibiotics were dispensed without prescription in 85.1% of visits. Among these, 54.9% were WHO "Watch" antibiotics (azithromycin, ciprofloxacin, cefixime, ceftriaxone) and 8.2% were "Reserve" antibiotics (oral colistin, levofloxacin) a fundamental inversion of appropriate AWaRe distribution. Only 3.8% of vendors provided AMR counseling. Outlets in high socio-economic neighborhoods had 2.45-fold higher odds of dispensing Watch/Reserve antibiotics (aOR: 2.45, 95%CI: 1.54–3.89), and specific customer request for azithromycin increased odds 3.12-fold (aOR: 3.12, 95%CI: 1.98–4.92). Formal pharmacy status was partially protective (aOR: 0.42, 95%CI: 0.24–0.73). Watch antibiotics predominated in urban areas (68.4%) vs. rural areas (43.1%). Inappropriate antibiotic dispensing for pediatric viral presentation is pervasive in Nigeria’s informal sector, with widespread use of WHO Watch and Reserve antibiotics driven by economic incentives and customer demand. These practices undermine antimicrobial stewardship and threaten the efficacy of last-line treatments. Urgent engagement with informal providers is needed to align community-level practices with national AMR strategies.