Effect of strengthening nosocomial infection control on distribution of pathogenic bacteria in hospital during coronavirus disease 2019 epidemic

ABSTRACT

Objective To explore the effect of strengthening nosocomial infection control measures on reducing the distribution of pathogenic bacteria in hospital environment during the outbreak of coronavirus disease 2019 (COVID-19), so as to provide support for epidemic prevention and safety. Methods A total of 160 sampling sites (45 by plate sedimentation method and 115 by swab method) were randomly selected as the control group before strengthening nosocomial infection control measures (from Dec. 21, 2019 to Jan. 21, 2020). After strengthening the measures (from Jan. 24 to Feb. 24, 2020), 160 sampling sites (64 by plate sedimentation method and 96 by swab method) were selected as the observation group. The changes of pathogenic bacteria distribution in the hospital environment before and after strengthening nosocomial infection control measures were compared. Results Before strengthening nosocomial infection control measures, 39 (24.4%) of 160 sampling sites were positive for pathogenic bacterial colonies, including seven (15.6%) positive in 45 by plate sedimentation method and 32 (27.8%) positive in 115 by swab method. After strengthening nosocomial infection control measures, 18 (11.2%) of 160 sampling sites were positive, including four (6.2%) positive in 64 by plate sedimentation method and 14 (14.6%) positive in 96 by swab method. Statistical analysis showed that there was no significant difference in the positive rate of pathogenic bacteria by plate sedimentation method after strengthening nosocomial infection control measures than that before strengthening nosocomial infection control measures. However, the positive rates of swab method and total pathogenic bacterial colonies were both significantly lower than those before strengthening nosocomial infection control measures (P=0.020 and 0.002). The pathogenic bacterial colony number sampled by plate sedimentation method after strengthening nosocomial infection control measures was (0.69±0.09) CFU/cm2, which was similar when compared with that before strengthening nosocomial infection control measures ([0.85±0.15] CFU/cm2). The pathogenic bacterial colony number sampled by swab method after strengthening nosocomial infection control measures was (0.19±0.06) CFU per plate, which was significantly lower than that before strengthening nosocomial infection control measures ([0.32±0.08] CFU per plate) (P=0.001). Conclusion During the outbreak of COVID-19, strengthening disinfection and improving disinfection quality can effectively reduce the pathogenic bacterial colonies in the hospital environment, reducing the risk of infection exposure of medical staff.