A Retrospective Study of Staphylococcus aureus Bacteremia in a Tertiary Hospital and Factors Associated with Mortality

Staphylococcus aureus bacteremia (SAB) is a severe infection frequently associated with significant morbidity and mortality. Recent studies have shown that SAB mortality has decreased during the last decades. However, about 25% of patients suffering from the disease will ultimately die. Hence, there is an urgent need for more timely and efficient treatment of patients with SAB. The aim of the present study was to retrospectively evaluate a cohort of SAB patients hospitalized in a tertiary hospital and to identify factors independently associated with mortality. All 256 SAB patients hospitalized from January 2005 to December 2021 in the University Hospital of Heraklion, Greece, were evaluated. Their median age was 72 years, while 101 (39.5%) were female. Most SAB patients were cared for in medical wards (80.5%). The infection was community-acquired in 49.5%. Among all strains 37.9% were methicillin-resistant S. aureus (MRSA), however, definite treatment with an antistaphylococcal penicillin was given only in 22% of patients. Only 14.4% of patients had a repeat blood culture after the initiation of antimicrobial treatment. Infective endocarditis was present in 8%. In-hospital mortality has reached 15.9%. Female gender, older age, higher McCabe score, previous antimicrobial use, presence of a central venous catheter, neutropenia, severe sepsis, septic shock, and MRSA SAB were positively associated with in-hospital mortality, while monomicrobial bacteremia was negatively associated. The multivariate logistic regression model identified only severe sepsis (p = 0.05, odds ratio = 12.294) and septic shock (p = 0.007, odds ratio 57.18) to be independently positively associated with in-hospital mortality. The evaluation revealed high rates of inappropriate empirical antimicrobial treatment and non-adherence to guidelines, as shown, by the lack of repeat blood cultures. These data underline the urgent need for interventions with antimicrobial stewardship, increased involvement of infectious diseases physicians, educational sessions, and creation and implementation of local guidelines for improvement of the necessary steps for timely and efficient SAB treatment. Optimization of diagnostic techniques is needed to overcome challenges such as heteroresistance that may affect treatment. Clinicians should be aware of the factors associated with mortality in patients with SAB to identify those who are at a higher risk and optimize medical management.

COVID-19 in Older Individuals Requiring Hospitalization

Older individuals have an increased risk for severe coronavirus disease 2019 (COVID-19) and a higher risk for complications and death. The aim of this study was to investigate the clinical characteristics of older patients admitted with COVID-19 and describe their outcomes. This was a retrospective cohort study of patients older than 65 years admitted to the COVID-19 Department of the University Hospital of Heraklion. Data recorded and evaluated included age, gender, Infectious Diseases Society of America (IDSA) severity score, Charlson comorbidity index (CCI), high-flow nasal oxygen (HFNO) use, admission to the Intensive Care Unit (ICU), laboratory exams, treatment administered, and outcome. In total, 224 patients were evaluated in the present study. The median age was 75 years and 105 (46.9%) were female. In 50 patients (22.7%), HFNO was used and 23 (10.3%) were admitted to the ICU. Mortality was 13.4% (30 patients). Patients that died had higher age, were more likely to be male, had an IDSA severity score of 3, had prior HFNO use, had been admitted to the ICU, and were also more likely to have a higher white blood cell (WBC) count, CRP, ferritin, procalcitonin, d-dimers, and troponin. A multivariate logistic regression analysis identified age and the need for HFNO use to be independently positively associated with mortality. To conclude, COVID-19 carries significant mortality in hospitalized older patients, which increases with age, while the need for HFNO also increased the likelihood of worse outcomes. Clinicians caring for patients with COVID-19 should bear in mind these two factors. Future studies could elaborate on the effect of new variants on the dynamics of mortality in older patients.

Infective endocarditis by Serratia species: a systematic review

Serratia species are facultative anaerobes, non-spore-forming, motile Gram-negative bacteria. Serratia spp. are currently thought to cause a variety of infections, such as bacteremia, urinary tract infections, and pneumonia, as well as other, less common infections, including ocular infections or skin and soft tissue infections. On the other hand, Infective Endocarditis (IE) is an infrequent disease with notable morbidity and mortality. Even though IE is rarely caused by Serratia spp., these infections can be quite problematic due to the lack of experience in their management. This study aimed to systematically review all published cases of IE by Serratia spp. in the literature. A systematic review of PubMed, Scopus, and Cochrane library (through 13^th May 2021) for studies providing epidemiological, clinical, microbiological data as well as data on treatment and outcomes of IE by Serratia spp. was performed. In total, 50 studies, containing data for 72 patients, were included. A prosthetic valve was present in 18.1%. The mitral valve was the most commonly infected site, followed by the aortic valve. The diagnosis was facilitated by transthoracic echocardiography in 34.7%, while the diagnosis was set at autopsy in 22.4%. Fever, sepsis, and embolic phenomena were the most common clinical presentations, followed by heart failure. Aminoglycosides, cephalosporins, and carbapenems were the most commonly used antimicrobials. Clinical cure was noted only in 53.5%, while overall mortality was 47.2%. Having surgery along with antimicrobial treatment was independently associated with reduced overall mortality. IE by Serratia spp. was more likely to be associated with intravenous drug use, and to present with heart failure and embolic phenomena compared to IE by other non-HACEK Gram-negative bacilli, while mortality was also higher in IE by Serratia spp.