Microbial Air Monitoring in Turbulent Airflow Operating Theatres: Is It Possible to Calculate and Hypothesize New Benchmarks for Microbial Air Load?

TiO2-Ag-NP adhesive photocatalytic films able to disinfect living indoor spaces with a straightforward approach

TiO₂-Ag doped nanoparticulate (TiO₂-Ag-NP) adhesive photocatalytic films were used to assess the ability in dropping down the burden of indoor microbial particles. The application of an easy-to use photocatalytic adhesive film to cleanse indoor living spaces from microbial pollution, represents a novelty in the field of photocatalytic devices. Reduction was attained by photocatalysis in selected spaces, usually with overcrowding (≥ 3 individuals) in the common working daily hours, and upon indoor microclimate monitoring. TiO₂-Ag doped nanoparticulate (TiO₂-Ag-NP) adhesive photocatalytic films were applied within five types of living spaces, including schools and job places. The microbial pollution was assessed at time 0 (far from routine clean, ≥ 9 h) and throughout 2-4 weeks following the photocatalyst application by relative light unit (RLU) luminometry and microbial indirect assessment (colony forming units per cubic meter, CFU/m³). TiO₂-Ag-NP photocatalyst reduced RLU and CFU/m³ by rates higher than 70% leading to RLU ≤ 20 and microbial presence ≤ 35 CFU/m³. The described TiO₂-Ag-NP is able to reduce microbial pollution to the lowest RLU threshold (≤ 20) within 60 min in open daylight in a standardized test room of 100 m². The correlation between RLU and CFU/m³ was positive (r = 0.5545, p < 0.05), assessing that the microbial reduction of indoor areas by the TiO₂-Ag-NP adhesive film was real. Titania photocatalysts represent promising tools to ensure air cleaning and sanitization in living indoor microclimates with a low cost, feasible and straightforward approach. This approach represents an easy to handle, cost effective, feasible and efficacious approach to reduce microbial pollution in indoor spaces, by simply attaching a TiO₂-Ag-NP adhesive film on the wall.

Air microbial sampling in operating theatres by active and passive methods: equation correlation from the GISIO-ISChIA study results and comparison with the EU GGMP recommendation, towards the definition of threshold values

The aim of this study was to calculate the equation of correlation between the microbial air contamination values obtained by active sampling (colony-forming units per cubic metre, CFU/m3) and by passive sampling (Index of microbial air contamination, IMA), by using the data from the ISChIA study, and to compare the values obtained with the recommended limits defined by the EU Guidelines to Good Manufacturing Practice (EU GGMP), 2008, for clean areas used to manufacture sterile medicinal products. Air sampling was performed during 335 elective prosthesis procedures. Correlation between CFU/m3 and IMA values was evaluated using the Spearman test; p<0.05 was considered to indicate significance. This equation was used to calculate the IMA values corresponding to the CFU/m3 recommended threshold values by EU GGMP for the different Grades of microbial contamination. The following correlation equation was obtained: y = 1.86 + 0.12x, where "x" = cfu/m3 value and "y" = IMA value. The relationships between CFU/m3 and IMA values obtained from active and passive sampling during the ISChIA study showed to be in line to those suggested by the EU GGMP for pharmaceutical manufacturing for Grade C and D. This study shows that the EU GGMP relationship could be considered valid also for operating theatres. Both methods, active and passive samplings, can be used to evaluate microbial air quality and highlight critical situations; however, in particular during the activity, passive sampling estimating the risk posed by airborne microorganisms to the surgical wound, can be considered more relevant, and for its simplicity, economy and standardization, can be suggested for routine microbial monitoring.

Current Status and Factors Associated with Clean Operating Rooms: A Survey of Hospitals in China

Background

Indoor air quality is controlled in the clean operating room (OR) to reduce the risk of surgical-site infections (SSIs). The aim of this study is to assess the usage and management of clean ORs in China and to identify factors associated with the risk of SSIs.

Methods

An online survey was distributed to hospitals in China from August 5 to September 5, 2018 via the WeChat account of the Shanghai International Forum for Infection Control and Prevention. The questionnaire consisted of two parts: basic information (hospital type, level, and number of beds) and usage and management (number of ORs, usage time, maintenance mode, test frequency, compliance with current standards, and comfort of healthcare workers). The significance of factors associated with the cleanliness and maintenance of clean ORs was assessed by univariate and multivariate logistic regression analyses.

Results

Among 1,308 responding hospitals, 25.7% failed to comply with current standards. “Maintenance mode” had a significant effect on compliance with current standards for clean ORs (p < 0.0001) and “professional” maintenance was superior to “outsource or no” maintenance (odds ratio = 0.511, 95% confidence interval = 0.367–0.711). There was a significant difference in the comfort of healthcare workers in clean ORs that complied with current standards vs. those that did not (39.92% [388/972] vs. 64.28% [216/336], respectively, p < 0.0001). Humidity was the chief complaint among healthcare workers.

Conclusion

Maintenance of clean ORs was significantly associated with the compliance of current standards. Noncompliance with current standards was associated with greater risks of SSIs. Maintenance of ORs for prevention of SSIs should consider the costs and benefits.