Elderly adults more likely to die from S. aureus bacteraemia
Advanced age, septic shock and liver cirrhosis increase the risk of mortality in adults with Staphylococcus aureus bacteraemia (SAB), a recent study has shown.
The 4-year retrospective observational study included 337 patients with SAB, of whom 35 percent (n=118) were aged >75 years. Clinical outcomes were compared between participants <75 vs ≥75 years. Multiple logistic regression analysis was performed to determine risk factors correlated with 7-day and 30-day hospital mortality.
Mortality by days 7 (20.3 percent vs 9.2 percent; p=0.004) and 30 (35.7 percent vs 20.7 percent; p=0.003) were significantly higher in the elderly vs younger adults. In the elderly adult group, septic shock was a risk factor for both 7-day (odds ratio [OR], 8.8; 95 percent CI, 2.7–32; p<0.001) and 30-day (OR, 2.7; 0.9–8.1) mortality.
In comparison, cirrhosis (OR, 8.4; 1.3–75.6; p=0.03) increased the likelihood of 7-day mortality, while adequate ab initio significantly reduced said risk (OR, 0.3; 0.1–0.9; p=0.03). Consultations for infectious diseases significantly reduced the risk of 30-day mortality in elderly adults (OR, 0.3; 0.1–0.7; p=0.006).
Notably, infection with methicillin-resistant S. aureus (MRSA) significantly increased the risk of 30-day mortality (OR, 2.4; 1.0–5.7; p=0.04). Such infections were reported in 39.2 percent (n=132) of the study sample and were equally distributed between the two age groups, though the elderly adults received empirical anti-MRSA treatment with significantly less frequency (15.0 percent vs 36.2 percent; p<0.001).