Objective To investigate a suspected outbreak of healthcare-associated infection with carbapenem-resistant Klebsiella pneumoniae (CRKP) in a geriatric emergency ward, and to provide references for the prevention and control of multidrug-resistant bacteria in a hospital in Shanghai.

Methods On-site epidemiological investigation, combined with environmental hygiene monitoring and pulsed field gel electrophoresis (PFGE) molecular typing method, were adopted to investigate a suspected outbreak of CRKP infection in the geriatric emergency ward of a hospital from October to November 2022, aiming at finding out factors caused the outbreak before taking corresponding control measures.

Results A total of 3 cases of healthcare-associated CRKP infection were identified, of which 2 cases were homologous to a previous case of community-associated CRKP infection. What’s more, the 2 cases lived in the same ward with the latter and with adjacent beds, but the third case was non-homologous to the community-associated infection case. A total of 46 samples were collected from the environmental surfaces and the hands of healthcare workers, of which 7 samples tested positive for CRKP and were identical to the strains from the 2 healthcare-associated infection cases and the 1 community-associated infection case, originating from the bedrails, bedside tables, surface of non-invasive ventilator, bed curtains and panels of monitoring equipment, with a detection rate of 15.22%. But none of the 11 samples from the hands of healthcare workers tested positive for CRKP. The outbreak was effectively controlled after taking specific prevention and control measures such as strengthening personnel management, intensifying environmental cleaning and disinfection and strictly enforcing hand hygiene among healthcare workers. Subsequently, no similar new cases were reported during the 14-day follow-up period.

Conclusion Incomplete environmental cleaning and disinfection, as well as inadequate enforcement of hand hygiene among heatheare workers may have contributed to the suspected outbreak of CRKP in the geriatric emergency ward. Early warning and timely investigation of suspected outbreaks of multidrug-resistant bacteria are crucial for preventing and controlling such outbreaks in hospitals.