P. aeruginosa, an opportunistic human pathogen, is a significant cause of hospital-acquired infections, especially in the United Kingdom and Europe. This was underscored in 2017 when the number of patients with P. aeruginosa bacteraemia, i.e., P. aeruginosa in the bloodstream, began to rise in a London teaching hospital. As a result, a case-control study was implemented to identify the pre-existing factors that increased the risk of acquiring P. aeruginosa bacteraemia among hospital inpatients – a significant portion of whom had compromised immune systems.
This in-depth investigation involved a multivariable, matched, case-control analysis using conditional logistic regression. The study was conducted in a tertiary care teaching hospital with 800 patient beds, including 98 for haematology patients. The cases comprised 137 patients who had hospital-onset P. aeruginosa detected in their blood samples. Comparatively, two control groups encompassed a total of 845 patients treated within the same duration.
The study utilized statistical analysis with SPSS and R software to evaluate cases based on various prediction variables including admission method, blood test results, known viral infection, presence of central lines, surgical history, urinary tract infection and presence of P. aeruginosa detected in urine, wound, or respiratory system.
A risk association was found between a white cell count ≤ 2 × 109/L and an increased likelihood of pseudomonas bacteraemia. Other risk factors included the presence of P. aeruginosa in urine or respiratory secretions and the number of central venous catheters.
Although the incidence of P. aeruginosa bacteraemia increased during the Covid-19 pandemic, it remained relatively uncommon. Nevertheless, the rate did rise slightly during this period and accounted for a considerable proportion of hospital-onset bacteraemia cases. Importantly, P. aeruginosa was found to be responsible for a noteworthy percentage of urinary and respiratory tract infections.
This investigation highlights the importance of examining specific risk factors in vulnerable patient groups, such as those admitted to haematology wards, as a means of prevention. It also points towards screen-and-treat strategies for managing P. aeruginosa bacteraemia in healthcare settings where such infections are prevalent, particularly during patient admission.
Understanding the impact of P. aeruginosa within the healthcare environment and identifying the factors that contribute to the risk of bacteraemia are vital steps towards improving patient outcomes and preventing future outbreaks.
Source: https://aricjournal.biomedcentral.com/articles/10.1186/s13756-025-01628-0