Treatment of Staphylococcus aureus bacteraemia

Editor—In his editorial on Staphylococcus aureus bacteraemia Paul says that some doubt remains about the optimal duration of antibiotic treatment.¹ A prospective study of 278 cases of S aureus bacteraemia (mainly methicillin sensitive strains) looked at potential risk factors and outcome, using multiple regression analysis.² Factors related to death were duration of treatment less than 14 days, an uneradicated focus, septic shock, total daily dose of flucloxacillin < 4 g, and age 60 years or more. Anecdotally, treatment of S aureus is often stopped before 14 days, as the patient seems to have recovered, and the requirement for this minimum length of treatment is not widely appreciated.

Figure 1.

Credit: CDC/SPL

Close liaison between infection specialists (microbiologists and infectious disease doctors) and clinicians also needs to be emphasised. In a study of 244 patients with S aureus bacteraemia, clinical outcome was improved (better eradication of S aureus and less relapses of infection) when advice from an infectious disease doctor was taken, compared with when it was not.³ However, telephoned blood culture advice is recorded in medical records in less than two thirds of cases,⁴ so verbal advice may be forgotten. In our hospital, an infectious disease doctor reviews at the bedside every case of S aureus bacteraemia on the medical and surgical wards. In this way, advice is given and documented on antibiotic choice, route of administration and duration, the removal of the infective focus when possible (such as intravascular lines), and the need for further investigations such as echocardiography.