Israel Medical Association Journal

Background: Gram-negative bloodstream infections (GN-BSI) are life threatening. Appropriate antimicrobial therapy and source control when indicated improve survival. Dementia is an independent risk factor for death and is associated with increased risk for infections, especially in advanced stages. Data about the best diagnostic and therapeutic approaches for patients with dementia and GN-BSI are lacking.

Objectives: To evaluate patients with dementia and GN-BSI and determine whether diagnostic imaging improves clinical outcomes.

Methods: We performed a retrospective cohort study of adult patients with GN-BSI, during 2019–2022. Patients with or without a diagnosis of dementia were compared. Outcomes were in-hospital mortality and recurrent bacteremia. Demographic, clinical, diagnostic, and therapeutic data were collected and analyzed.

Results: A total of 87 patients with dementia and 130 without were included. Patients with dementia received appropriate empirical antimicrobial therapy in 38% of cases compared to 62% of patients without dementia, P < 0.001. Imaging studies were performed in half of patients in both groups. In the dementia group, 17% had abnormal findings that required source control versus 30% in the control group (P = 0.049). Source control was performed in 15% of patients with dementia versus 28% of patients without dementia (P = 0.032). Mortality was 27.6% in the dementia group versus 22.3% in the control group (P = 0.42).

Conclusions: In patients with dementia and GN-BSI, imaging studies have lower effect on clinical outcomes. Imaging studies should be performed in selected cases only and not conducted routinely.

Background: Isolation of methicillin-resistant Staphylococcus aureus (MRSA) in healthy individuals is not common in Israel. In our hospital, about 30% of MRSA isolates were SCCmec types IV and V.

Objectives: To identify the demographic and clinical characteristics of patients carrying MRSA SCCmec type IV or V, and to compare them with each other and with those of patients with SCCmec types I-III.

Methods: We conducted a case-control study that included 501 patients from whom MRSA was isolated: 254 with SCCmec type I, II, or III, and 243 isolates from SCCmec types IV or V. 

Results: MRSA was isolated from surveillance cultures in 75% of patients and from a clinical site in 25%. The majority of our study population was elderly, from nursing homes, and with extensive exposure to health care. First, we compared characteristics of patients identified through screening. Statistically significant predictors of SCCmec V vs. IV were Arab ethnicity (OR 7.44, 95%CI 1.5–37.9) and hospitalization in the year prior to study inclusion (OR 5.7, 95%CI 1.9–16.9). No differences were found between patients with SCCmec types I-III and patients with SCCmec type IV or V. Analysis of the subset of patients who had clinical cultures yielded similar results. 

Conclusions: SCCmec types IV and V were common in the hospital setting although rare in the community. It seems that in Israel, SCCmec IV and V are predominantly health care-associated MRSA.