Staphylococcus aureus septicemia in non-neutropenic adult patients hospitalized in internal medicine units

Gallucci F, Amato G, Esposito P, Belli CMC, Russo R, Uomo G

Abstract

Purpose: Staphylococcus aureus septicemia (SAS) is usually described in immunocompromised patients and during serious weakening diseases, associated with a neutropenic condition. Over the last recent years, clinic relevance of SAS has become more prominent owing to the progressive rise of methicillin-resistent strains in hospital-acquired infections and to its development in non-neutropenic patients.
Material and methods: The aim of our study was to evaluate the clinical features and outcome of non-neutropenic patients with positive blood culture for Staphylococcus aureus (SA) hospitalized in Internal Medicine Wards of our hospital during 1 year of observation. 24 patients with those characteristics were retrospectively recruited; five of them were then excluded from the analysis because of concomitant oncohematologic disease. The median age of the study group of patients (19 cases) was 56 years (range 18-87); 10 (52.6%) patients were male.
Results: Infection was hospital-acquired in 10 patients (52.6%). Predisposing factors were: central venous catheter (CVC) (47.4%), recent surgical intervention (21.0%), drug-addiction (15.8%). Main comorbidities were diabetes mellitus in 10 patients (52.6%), heart disease in 4 (21.0%), chronic renal failure in 3 (15.8%), cerebral vascular disease in 3 (15.8%). Fever >38°C was found in all patients at the moment of SA isolation in blood culture. SA isolated-strains were methicillin-resistant in 7 patients (36.8%). Complications of bacteremia were: pneumonia in 4, endocarditis in 3, vertebral osteomyelytis in 2, septic splenic embolization in 1 and endophtalmitis in 1 patient. The septicemia-attributable mortality was 36.8% (7 patients).
Conclusions: SAS in non-neutropenic patients observed in Internal Medicine Units are associated with significant morbidity and mortality, closer to that reported for neutropenic illnesses. 

Key words:	Staphylococcus aureus, sepsis, nosocomial infections.