Investigation and control of a suspected outbreak of carbapenem-resistant Klebsiella pneumoniae bloodstream infection in patients with hematologi-cal tumors / 中国感染控制杂志

ABSTRACT

Objective To investigate a suspected outbreak of carbapenem-resistant Klebsiella pneumoniae(CRKP)healthcare-associated bloodstream infection(HA-BSI),provide reference for effective control of CRKP in-fection.Methods The characteristics of CRKP infected patients and the risk factors for the event transmission in an adult hematology department of a teaching hospital in June 2022 were obtained by field epidemiological investigation.The specimens of environmental target strains were co-llected by blood nutrient agar inoculation,the removal status of environmental microorganisms and the effect of infection control after implementing control measures were com-pared.Results There were a total of 6 cases of CRKP HA-BSI,with an attacking rate of 1.29％(6/464),which was significantly higher than 0 during the same period in 2021,and difference was statistically significant(P=0.011).In environmental hygiene monitoring,the detection rate of CRKP was 2.27％(1/44),which was from the surface of bed curtain in the living unit of infected patients,homology analysis with CRKP detected from 2 patients revealed that the 16s RNA of 3 CRKP strains was completely identical,with a similarity of 100％.Seven house-keeping genes of 3 CRKP strains were all identical and belonged to the ST11 type.Comprehensive control measures were taken:appropriate closure of the ward,centralized isolation of patients,terminal disinfection of the ward,reg-ular health care workers and relative restriction of their activity areas.After the measures were taken,the qualified rate of microbial colony count in the ward increased compared to before taking the measures(2.27％vs 68.89％,P＜0.001),with a statistically significant difference,there were no more CRKP infected cases after the intervention,indicating that the control measures were effective.Conclusion This outbreak was caused by ST11 type of common CRKP in China,and laminar bed curtains are carriers of pathogen transmission.It is speculated that non-standard cleaning and disinfection,as well as inadequate implementation of hand hygiene are the main causes for transmis-sion.Adopting an appropriate strategy of closing the ward and concentrating patient isolation can quickly and effec-tively prevent the transmission of the event.