Risk and Distribution of Metastatic Infections by Primary Infection Focus in Staphylococcus aureus Bacteremia.

Background: Staphylococcus aureus bacteremia (SAB) is a significant cause of morbidity and mortality, with a high risk of metastatic infections. Understanding the timing and distribution of metastatic infections based on the primary infection focus is crucial for effective management. We aimed to identify patterns that could guide clinicians in prioritizing surveillance and interventions for patients at high risk of metastatic infection.

Methods: This retrospective cohort study analyzed 1725 patients diagnosed with SAB. We assessed the incidence and distribution of metastatic infections within the cohort, stratifying the data by the timing postdiagnosis and the primary infection focus.

Results: In the cohort of 1725 patients, 289 (16.7%) experienced a total of 439 metastatic infection events within the 90-day follow-up period. The majority of metastatic infections (approximately 85%) occurred within the first 7 days following diagnosis. The incidence of metastatic infections varied significantly with the primary focus of SAB, being highest in patients with endocarditis at 73.4%. The lung was the most frequent metastatic site (23.7%), followed by bones and joints (16.8%) and the central nervous system (12.3%). The distribution of metastatic sites significantly differed according to the primary infection focus.

Conclusions: Our study findings provide essential insights into the risk and distribution of metastatic infections in patients with SAB, highlighting the critical role of the timing and primary infection focus. These findings enable healthcare professionals to adopt a more proactive and targeted approach to managing patients with SAB.