Staphylococcus aureus bacteraemia of unknown primary source: where do we stand?

Area of Science:

• Infectious Diseases
• Clinical Microbiology
• Public Health

Background:

• Staphylococcus aureus bacteraemia (SAB) of unknown source lacks a universal definition.
• The incidence of SAB, particularly community-acquired (CA-SAB), is increasing.
• Intravenous drug use and indwelling intravascular devices are key drivers of SAB.

Purpose of the Study:

• To define Staphylococcus aureus bacteraemia (SAB) of unknown source.
• To review the rising incidence and drivers of SAB, including community-acquired (CA) and hospital-acquired (HA) infections.
• To highlight the risks of metastatic infection, such as infective endocarditis (IE), and the role of diagnostic imaging.

Main Methods:

• Literature review and clinical case analysis.
• Definition of SAB of unknown source based on clinical findings and investigations.
• Evaluation of diagnostic modalities for metastatic complications.

Main Results:

• SAB incidence is rising, with increased community-acquired (CA) and hospital-acquired (HA) cases.
• Metastatic infections, including infective endocarditis (IE), are significant risks.
• Transoesophageal echocardiography is a superior method for detecting IE in SAB patients.

Conclusions:

• A clear definition for SAB of unknown source is proposed.
• The increasing prevalence of meticillin-resistant S. aureus (MRSA) necessitates further study.
• Early recognition and management of metastatic complications are vital for improving outcomes in SAB.