Abstract: Objective: To investigate and control the aggregation of Carbapenem-Resistant Klebsiella Pneumoniae (CRKP) infection in a certain ICU, and provide reference for prevention and control of multi-drug resistant organisms infection. Methods: Molecular epidemiological investigation was conducted on 4 cases of clustering of CRKP infections from February 1 to March 31, 2018. Environmental microorganisms were tested to find CRKP in the environment. Rep-PCR typing technique was used to analyze the homology between patients and environmental isolates. Comprehensive control measures were taken to analyze the control effect. Results: The four cases of CRKP infection, including 2 cases of nosocomial infection, and the infection rate was 4.07‰, higher than the same period of 2017, although the difference was not statistically significant (P=0.232). The nosocomial infection rate of CRKP reached the highest level in years, and there was a tendency of aggregation. Rep-PCR homology analysis showed that CRKP isolated from patient A, B, C and bedrail of patient B was the same genotype, and patient D was of other genotypes. Patient A was a community infection, and patient B and C were nosocomial infections, indicating that CRKP has transmitted within the ICU. After taking comprehensive control measures, no cases of secondary infection occurred, which was statistically different from that before the intervention (P=0.021). Conclusion: Molecular epidemiological investigations can identify the source and high risk of infection. In-situ clinical investigation and observation can help to identify the risk of infection. The effective implementation of measures is the key to prevent infection and aggregation.

Key words: Carbapenem-Resistant Klebsiella Pneumoniae; nosocomial infection; molecular epidemiology; investigation