OBJECTIVE To investigate a suspected outbreak of carbapenem-resistant Klebsiella pneumoniae (CRKP) infection in the intensive care unit of a traditional Chinese medicine hospital, identify the source of infection and transmission routes, and provide a basis for prevention and control of CRKP infection.

METHODS Epidemiological investigations were conducted on five patients with CRKP infections or colonization who were identified in Jul. 2024 at Suiyang County Hospital of Traditional Chinese Medicine. Samples were collected from patients, the ward environments, and hand surfaces to detect CRKP. Fourteen CRKP isolates were selected for carbapenemase gene testing, and homology analysis was performed by enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) and multilocus sequence typing (MLST).

RESULTS The median age of the five cases was 73 years, and all had undergone multiple invasive procedures. Environmental monitoring showed a CRKP positive rate of 26.35%, with CRKP isolates detected on the hands of healthcare workers, surfaces in the wards and medical equipment surfaces. Genetic analysis showed that all 14 CRKP strains carried the KPC resistance gene; except for case 1, other strains carried the VIM gene. MLST identified CRKP of all strains as sequence type 48 (ST48); while ERIC-PCR revealed two distinct genotypes: genotype A for case 1 and genotype B for the other cases and environmental isolates. After strengthening patient isolation and group treatment, strictly cleaning and disinfecting the ward environments and medical equipment, and strictly implementing hand hygiene, the infection was effectively controlled.

CONCLUSIONS Inadequate disinfection of the ward environments and medical equipment and poor compliance with hand hygiene are the main contributors to the suspected CRKP outbreak. Homology analysis suggests the existence of two independent transmission chains. Timely identification and management of the infection sources, interruption of transmission routes, protection of susceptible individuals and implementation of comprehensive infection control measures are essential for effective outbreak control.