The Infectious Disease Society of America and European Society of Clinical Microbiology and Infectious Disease released Part 1 of their latest Consensus Statements on Staph aureus Bacteremia on September 9. The document addresses risk stratification and management for adults and children. This specific update focuses on two questions regarding treatment length. One statement asks whether low-risk patients with no evidence of deep-seated or metastatic foci require treatment for 14 days or less. The second addresses increased-risk patients in the same category, questioning whether they need treatment of 14 days or longer.
Standardizing Treatment Duration
Staphylococcus aureus bacteremia is the leading cause of death from bloodstream infection and causes substantial morbidity due to frequent deep-seated and metastatic foci of infection. The statements suggest a 14-day course of therapy for adults classified as low-risk and increased-risk without evidence of deep-seated or metastatic foci. The guidelines recommend using the day of blood culture clearance as the start date of treatment. If a focus of infection is removed after blood cultures clear, that date can also mark the beginning of therapy.
Per the consensus, the literature does not suggest a benefit to treating low-risk patients for any longer than 14 days. Prolonged treatment puts patients at risk for adverse drug reactions and complications associated with prolonged hospitalization, including venous thromboembolism and additional infections. The statement suggests administering 14 days of therapy is feasible in most clinical settings. Treatment less than 14 days should only be guided by an Infectious Disease specialist after careful risk assessment.
For patients with increased-risk SAB, the literature also supports a 14-day course that balances risks versus benefits. The statement reinforces that improvement in signs and symptoms and ongoing clinical assessment should not indicate a deep-seated or metastatic focus is present. Patients categorized as increased-risk based on positive blood cultures obtained 48 hours or more after the first positive culture should have additional evaluation for deep-seated or metastatic focus of infection.
Consensus Statement 7 recognizes certain clinical situations where device-related or endovascular infection may be difficult to exclude, including retained intracardiac devices and recently placed endovascular grafts. In these cases, the statement suggests considering additional source control and/or more than 14 days of antibiotic therapy targeting the suspected focus. If any focus of infection is identified that merits antibiotic treatment beyond 14 days, that focus should dictate the final duration of therapy.
Addressing Barriers to Implementation
Discharge protocols vary between different facilities. Limited access to outpatient antibiotic infusions is a common issue. Follow-up upon discharge is also a critical concern. Limited access to follow-up care can make it difficult to assess for infection resolution. Providers cannot easily monitor for new signs of relapse or new sites of infection. The availability of certain diagnostic tools to evaluate for deep-seated infections may vary between different healthcare organizations. Limited evidence addressing certain patient populations may lead to under or over treatment. Lack of infectious disease services may limit risk-based clinical assessments to determine the optimal treatment duration in certain individuals.