An evaluation of a Stenotrophomonas maltophilia outbreak due to commercial arterial blood gas collection kit.

BACKGROUND: Stenotrophomonas maltophilia is a gram-negative bacterium that can cause hospital infections and outbreaks within hospitals. This study aimed to evaluate an outbreak of Stenotrophomonas maltophilia, caused by ready-to-use commercial syringes containing liquid lithium and heparin for arterial blood gas collection in a university hospital. METHODS: Upon detecting an increase in Stenotrophomonas maltophilia growth in blood cultures between 15.09.2021 and 19.11.2021, an outbreak analysis and a case-control study (52 patients for the case group, 56 patients for the control group) were performed considering risk factors for bacteremia. Samples from possible foci for bacteremia were also cultured. Growing bacteria were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The genetic linkage and clonal relationship isolates were investigated with pulsed-field gel electrophoresis (PFGE) in the reference laboratory. RESULTS: In the case-control study, the odds ratio for the central venous catheter [3.38 (95% confidence interval [CI]: 1.444, 8.705 ; p = 0.006)], for surgery [3.387 (95% confidence interval [CI]: 1.370, 8.373 ; p = 0.008)] and for arterial blood gas collection history [18.584 (95% confidence interval [CI]:4.086, 84.197; p < 0.001)] were identified as significant risk factors. Stenotrophomonas maltophilia growth was found in ready-to-use commercial syringes used for arterial blood gas collection. Molecular analysis showed that the growths in the samples taken from commercial syringes and the growths from blood cultures were the same. It was decided that the epidemic occurred because the method for sterilization of heparinized liquid preparations were not suitable. After discontinuing the use of the kits with this lot number, the outbreak was brought under control. CONCLUSIONS: According to our results, disposable or sterile medical equipment should be included as a risk factor in outbreak analyses. The method by which injectors containing liquids, such as heparin, are sterilized should be reviewed. Our study also revealed the importance of the cooperation of the infection control team with the microbiology laboratory.

Invasive Fungal Infections in Children with Leukemia: Clinical Features and Prognosis

Objective: The incidence of invasive fungal infections (IFIs) has increased due to intensive chemotherapy in childhood leukemia. The aim of this study was to evaluate the incidence, risk factors, causative pathogens, and impact on survival of IFIs among pediatric leukemia patients. Materials and Methods: The hospital records of 307 children with acute lymphoblastic leukemia (ALL, n=238), acute myeloid leukemia (AML, n=51), and relapsed leukemia (n=18) between January 2010 and December 2015 were retrospectively evaluated. Results: A total of 1213 febrile neutropenia episodes were recorded and 127 (10.4%) of them were related to an IFI. Of 307 children, 121 (39.4%) developed IFIs. The mean age was significantly older in the IFI group compared to children without IFIs (p<0.001). IFIs were defined as possible, probable, and proven in 73.2%, 11.9%, and 14.9% of the attacks, respectively. Invasive aspergillosis (81.9%) was the most frequent infection, followed by invasive candidiasis (13.4%) and rare fungal diseases (4.8%). The majority of IFI attacks in both ALL and AML occurred during the induction phase. In total, the death rate was 24% and the IFI-related mortality rate was 18%. The mortality rate among children with IFIs was found to be significantly higher than that of children without IFIs (p<0.001). Overall and event-free survival rates at 5 years were also found to be significantly lower in the IFI group (p<0.001). Relapse (odds ratio: 8.49) was the most effective risk factor for mortality, followed by developing an IFI episode (odds ratio: 3.2) and AML (odds ratio: 2.33) according to multivariate regression analysis. Conclusion: Our data showed that IFIs were more common in older children. Although proven and probable IFI episodes were more frequently diagnosed in cases of relapse and AML, children with ALL and AML had similar frequencies of experiencing at least one episode Conclusion: Our data showed that IFIs were more common in older children. Although proven and probable IFI episodes were more frequently diagnosed in cases of relapse and AML, children with ALL and AML had similar frequencies of experiencing at least one episode