Effectiveness of copper contact surfaces in reducing the microbial burden (MB) in the intensive care unit (ICU) of hospital del Cobre, Calama, Chile

Abstract

Background: The environment plays a role as reservoir and transmission of microbes in hospital settings. In vitro studies have demonstrated the microbicidal activity of copper (Cu). We studied the ability of Cu to reduce the MB associated with commonly contact surfaces within an ICU of Hospital del Cobre de Calama, located in a semi-desert area in the north of Chile. Methods: Copperized (Cu) surfaces (bed rails, bed lever, tray tables, chair arms, touch screen monitor stylus, and IV poles) were placed into 3 randomly selected ICU rooms. Three paired rooms were compared by measuring the MB during 18 weeks. The mean(m) MB for each Cu object, determined as colony forming units (cfu)/100cm2 was compared to noncopper rooms. Antimicrobial efficacy of Cu was calculated as the difference in mMB between the Cu and non-Cu objects. The environmental cleaning procedures were equivalent for Cu and non-Cu rooms. The Kruskal-Wallist test for two groups was used. Results: The mMB associated with 594 Cu surfaces from 54 rooms containing Cu was compared against the mMB of equivalent surfaces from 54 non-Cu rooms from an ICU with humidity between 7.2 to 19.7%. Cu was effective in reducing mMB on all 6 surfaces tested (bed rails by 86%, bed lever by 84%, tray tables by 93%, chair arms by 88%, monitor pen by 49%, and IV poles by 89%). Total mMB count in rooms with Cu (2,142 cfu/100cm2) was significantly lower than in rooms without Cu (13,215 cfu/100cm2) p < 0.00001 Staphylococci were the most predominant microorganism isolated. Cu was equivalently effective and significant in reducing the staphylococcal burden associated with the objects, p < 0.00001. MRSA and VRE were never isolated, regardless of the presence of Cu. Gram negatives were infrequently isolated from some surfaces, and Cu reduced the Gram negative burden by 74%–88%. Conclusion: The antimicrobial effect of Cu was evident and significant in this arid region of Chile; reduced the total mMB, mMB of staphylococcal and Gram negative in ICU rooms containing Cu. Further studies regarding the clinical impact of reducing the mMB by Cu objects within the environment of hospitals is warranted. Abstracts for SupplementInternational Journal of Infectious DiseasesVol. 14Preview Full-Text PDF Open Archive