Real-World Effectiveness of Disinfection Protocols in Reducing SARS-Cov-2 RNA Contamination on Hospital Surfaces: A Case Study from a Warm and Arid Region in Southwestern Iran

Abstract

Introduction: Hospital surfaces may contribute to SARS-CoV-2 transmission; however, the real-world effectiveness of disinfectants is unclear. This study evaluated routine disinfection protocols using 0.5% sodium hypochlorite and 70% ethanol to reduce SARS-CoV-2 RNA contamination on high-touch hospital surfaces.

Methods: A total of 152 surface samples were collected from five high-touch surface categories (door handles, bed rails, computer keyboards, toilet door handles, and toilet faucets) before and after disinfection in a hospital in southwestern Iran (September 2020 -February 2021). SARS-CoV-2 RNA was detected using RT-qPCR targeting RdRp and N genes. Reduction percentages were calculated using McNemar's test.

Results: Overall, RNA was detected in 41/76 samples (53.9%) before versus 5/76 (6.6%) after disinfection (87.8% reduction, p<0.001). Sodium hypochlorite reduced contamination from 47.4% to 7.9% (83.3% reduction), while ethanol reduced from 60.5% to 5.3% (91.3% reduction). Complete RNA reduction (100%) was achieved on door handles, keyboards, and toilet surfaces, with no detectable RNA after disinfection. Residual RNA was observed on bed rails in both groups (20.0% with hypochlorite, 10.0% with ethanol), accounting for 60% of post-disinfection positives. Toilet faucets showed residual RNA only with hypochlorite (14.3%), while toilet door handles only with ethanol (14.3%). All reductions were significant (p<0.05).

Conclusion: Both disinfectants effectively reduced SARS-CoV-2 RNA under the operational conditions evaluated, with no claim of superiority for either agent. However, bed rails remain a persistent hotspot despite routine disinfection, highlighting the need for enhanced protocols and targeted monitoring.