Bacterial contamination map of high-touch surfaces in a hospital ophthalmology department: A cross-sectional study

Abstract

Background and objectives

Bacterial contamination of high-touch surfaces can facilitate healthcare-associated infections, particularly in ophthalmology, where frequent contact with diagnostic devices occurs. The aim of this study was to evaluate and characterize bacterial load on high-touch surfaces in a hospital ophthalmology department, identifying critical areas and predominant bacterial groups.

Material and methods

Cross-sectional observational study conducted in a tertiary hospital, sampling 150 surfaces across consultation rooms, emergency areas, waiting rooms, administrative areas, and critical points. Surfaces were sampled using sterile swabs and cultured on nutrient agar. After incubation at 37 °C for 48 h, bacterial load was quantified as colony-forming units per square centimeter (CFU/cm²). Bacterial identification was performed using Gram staining and conventional biochemical tests. Comparisons between areas were analyzed using ANOVA; P <  .05.

Results

Significant differences in bacterial load were observed among areas; P <  .001, with higher values in consultation rooms (104 ± 37 CFU/cm²) and critical points (118 ± 42 CFU/cm²). The most contaminated surfaces were slit-lamp chin rests, keyboards and mice, touch screens, and tonometer cones. Coagulase-negative staphylococci predominated (79%), followed by Staphylococcus aureus (14%) and Gram-negative bacilli (9%).

Conclusions

Frequently touched surfaces in ophthalmology departments exhibit high bacterial loads, underscoring the need for differentiated cleaning protocols, periodic audits, and staff training to reduce cross-contamination and improve patient safety.