Comparative efficacy of 3rd generation quaternary ammonium compounds and formaldehyde for fumigation of operation theatres

Objectives: The aim of this study was to evaluate and compare the efficacy of 3 rd generation quaternary ammonium compounds and formaldehyde for fumigation of operation theatres. Materials and Methods: Fumigation and fogging of operation theatres by formaldehyde and 3 rd generation quaternary ammonium compounds respectively were done by standard procedures. A total of 144 samples (swabs as well as open plates) each were collected prior and after fumigation by formaldehyde during the 1 st half (October – November 2012) and 144 samples prior and after spray fogging by 3 rd generation quaternary ammonium compounds in 2 nd half (December – January 2013) of the study. The samples were then cultured onto 5% defibrinated sheep blood agar and Mac Conkey agar and identification of the isolates were done following standard bacteriological techniques. Results: Reduction in the number of pathogens before and after disinfection by formaldehyde was 70.83 % (n=102) to 19.44% (n=28). In contrast, the reduction in bacterial growth prior and after fogging by 3 rd generation quaternary ammonium compounds was from 74.3% (n=107) to 13.88 % (n=20). Coagulase Negative Staphylococcus and Pseudomonas aeruginosa were the prevalent organisms isolated from all the samples. Formaldehyde based fumigation, although widely used in health care settings, may not be as good disinfectants as newer formulations like 3 rd generation quaternary ammonium compounds not because of its less effectiveness but keeping in view its toxic effect and carcinogenicity. Conclusion: Newer quaternary ammonium compound (QAC) formulations can be used in health care settings for disinfection of operation theatres instead of the relatively toxic and carcinogenic formaldehyde.