Environmental microorganisms monitored in a hospital in Tangshan, China, 2021

Objective To investigate the environmental microbial monitoring and its distribution characteristics in key areas of a hospital in Tangshan, China, so as to strengthen the management of hospital environmental sanitation.

Methods Air samples, object surface samples, and hygienic hand samples of medical staff were collected from seven key areas of a hospital in Tangshan during the 12 months of 2021. Bacterial culture and strain identification were performed according to the 4th edition of the National Clinical Laboratory Practice. The total number of colonies in the samples was determined once a month.

Results In 2021, the qualified rate of samples from key areas of a hospital in Tangshan was 96.8% (97.1% of indoor air samples, 95.7% of object surface samples, and 96.9% of hand hygienic samples). The total numbers of colonies in air, object surface, and hygienic hand samples were (2.4±0.3) CFU/plate, (3.2±0.3) CFU/cm², and (3.1±0.2) CFU/cm², respectively. There were significant differences in qualified rate of the total number of colonies among different key regions (χ²=40.65, P < 0.05). Further comparison between two groups showed significant differences between emergency department and outpatient department as well as between CT room and fever outpatient department (P < 0.002 27). There was a significant difference in the total number of colonies in the air samples from different key areas(χ²= 44.23, P < 0.05). Outpatient department showed significant differences in qualified rate as compared with emergency department and CT room (P < 0.002 27). There were no significant differences in the total number of colonies in the object surfaces samples and hygienic hand samples among key regions (P>0.05). A total of 165 strains of 14 species in 5 genera were identified from 140 unqualified samples, mainly including coagulase negative staphylococcus, Staphylococcus hominis, and Bacillus subtilis, accounting for 35.7% (59/165), 23.6% (39/165), and 23.6% (39/165), respectively.

Conclusion The qualified rate of the total number of colonies in key areas of the hospital is generally high, and the identified microbes are mainly gram-positive cocci. The risk of hospital infection is low, but the emergency department and CT room still need to further strengthen daily disinfection and microbial monitoring.