Bacterial Contamination Level of Indoor Air and Surface of Equipment in the Operation Room in Dil-Chora Referral Hospital, Dire Dawa, Eastern Ethiopia

PURPOSE: This study investigated the bacterial contamination level of the indoor air and surface of the operation room, surgical, and gynecology wards of Dilchora Referral hospitals between January and August 2020. METHODS: A laboratory based cross-sectional study was carried out on the OR and wards of Dilchora referral hospital in Eastern Ethiopia. A passive air sampling method was used to collect 128 indoor air samples; the bacterial load was enumerated and the result was expressed as colony forming units (CFU/m(3)). Additional qualitative analysis was carried out to identify particular bacterial species that were isolated from the indoor air and swabs taken from the surface of the equipment using conventional techniques. All laboratory data were entered and analyzed using MS Excel 2007 and SPSS version 20. RESULTS: The mean bacterial counts of 94.63 CFU/dm/hr in major OR during active time as well as 509.75 and 509.38 CFU/dm/hr in male and female clothing rooms during the afternoon were unacceptable (>450 CFU/dm(2)). Similarly, 43.75% of the bacterial counts found in the afternoon samples fell short of Fisher’s criterion. The difference between the bacterial counts recorded in the morning and afternoon was significant (p=0.000). A total of 54 (42.2%) indoor air samples and 28 (93.3%) cotton swabs were positive for bacterial growth, with S. aureus (51.04%) and Bacillus sp (55%) being the dominant bacteria isolated from indoor air and the surface of equipment, respectively. CONCLUSION: The bacterial load of investigated wards is considerably “high” to “very high”, which implies a significant risk of hospital acquired infections. Therefore, devising effective control strategies targeted on surface cleansing and sterilizing of the air environment and practicing periodic microbial surveillance of the hospital environment is a paramant.