Your patient has a blood culture positive for Staphylococcus aureus – what do you do?

Abstract

Staphylococcus aureus bacteraemia is an important clinical problem associated with a high mortality rate and a significant burden on healthcare resources. The severity, rate of complications, and prognosis of the infection depend on a multitude of factors including underlying patient factors, the virulence of the strain of S. aureus, and the timeliness of appropriate antibiotic therapy.

Detection of staphylococci in blood culture should trigger a chain of events beginning with assessment of the patient to determine signs of sepsis and the likely significance of the organism isolated. The level of risk of your patient having MRSA must be assessed. A deep-seated source, or metastatic complication, of the bacteraemia must be suspected and sought, with the most important complication being endocarditis. This assessment should not delay urgent treatment with IV antibiotic therapy in a patient with signs of sepsis. Treatment should be guided by local antibiotic policy alongside advice from microbiology and/or infectious diseases consultants.

This overview takes the form of a clinical case scenario with a step-wise approach to the management of a patient from first isolation of staphylococci in a blood culture to the management of MRSA endocarditis.