Staphylococcus aureus bacteremia in solid organ transplant recipients: evidence for improved survival when compared with nontransplant patients.

BACKGROUND

Staphylococcus aureus bacteremia (SAB) is an important cause of morbidity and mortality. Herein, we describe the incidence, clinical characteristics, and outcomes of SAB after solid organ transplantation (SOT) and compare these features with non-SOT controls.

METHODS

In a single-center retrospective study, blood cultures positive for S. aureus were obtained from January 1, 2000, to December 31, 2008. Chart review was performed on all SOT recipients with SAB. The social security death index was used to determine all-cause mortality.

RESULTS

Seventy of 2959 patients with SAB were SOT recipients (26 lung, 19 liver, 18 kidney, and seven heart). The overall attack rate of SAB in SOT was 22.9/1000 transplant patients. Early-onset SAB (≤ 90 days) was more frequent in liver recipients (79%), when compared with kidney recipients (17%). All-cause 30-day and 1-year mortality rates were 6% and 28% in SOT, respectively. Pneumonia as a source was associated with an increased 30-day mortality (18% vs. 2%, P = 0.04). Comparing SOT versus non-SOT controls, methicillin resistance was more frequent (86% vs. 52%, P < 0.0001), and duration of bacteremia was longer (mean 3.8 vs. 1.6 days, P < 0.01). SOT status was independently associated with lower risk of 30-day mortality (risk ratio [RR]: 0.37, P = 0.02).

CONCLUSIONS

In our cohort of SOT recipients, SAB was less common than previously reported and surprisingly had lower 30-day mortality, when compared with non-SOT. In SOT recipients, pneumonia as a source of SAB in SOT is associated with an increased 30-day mortality.