Clinical and virulence factors related to the 30-day mortality of Klebsiella pneumoniae bacteremia at a tertiary hospital: a case-control study.

Klebsiella pneumoniae bacteremia is a critical clinical presentation that is associated with high mortality. However, extremely few studies have investigated the virulence factors related to mortality of K. pneumoniae bacteremia in patients. The present study elucidated clinical and virulence factors associated with the 30-day mortality of K. pneumoniae bacteremia at a tertiary hospital. The medical records of 129 patients with K. pneumoniae bacteremia admitted to Osaka City University Hospital between January 2012 and December 2018 were retrospectively reviewed. Patient background characteristics, antimicrobial regimens, and prognosis were evaluated. Additionally, virulence factors were assessed using multiplex polymerase chain reaction to elucidate their association with K. pneumoniae. The 30-day mortality was 10.9% in patients with K. pneumoniae bacteremia. The male-to-female ratio, age, and underlying disease did not differ between the non-survivor and survivor groups. Multivariate analysis showed that sepsis (odds ratio (OR), 7.46; p = 0.005) and iutA (OR, 4.47; p = 0.046) were independent predictors associated with the 30-day mortality of K. pneumoniae bacteremia. Despite the relatively low 30-day mortality of patients with K. pneumoniae bacteremia, the treatment of those with sepsis and those infected with K. pneumoniae harboring iutA may require careful management for improving their outcomes.