Persistence in Staphylococcus aureus bacteremia: Incidence, characteristics of patients and outcome

• Published in: Scandinavian journal of infectious diseases 2006, Vol.38 (1), p.7-14
• Main Authors: Khatib, Riad, Johnson, Leonard B., Fakih, Mohamad G., Riederer, Kathleen, Khosrovaneh, Amir, Shamse Tabriz, M, Sharma, Mamta, Saeed, Sajjad
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents - therapeutic use; Bacteremia - complications; Bacteremia - drug therapy; Bacteremia - epidemiology; Bacteremia - microbiology; Bacterial diseases; Bacterial sepsis; Biological and medical sciences; Drug Resistance, Multiple, Bacterial; Female; Human bacterial diseases; Humans; Incidence; Infectious diseases; Male; Medical sciences; Middle Aged; Risk Factors; Staphylococcal Infections - complications; Staphylococcal Infections - drug therapy; Staphylococcal Infections - epidemiology; Staphylococcal Infections - microbiology; Staphylococcal infections, streptococcal infections, pneumococcal infections; Staphylococcus aureus; Staphylococcus aureus - drug effects; Staphylococcus aureus - isolation & purification; Staphylococcus aureus - physiology; Time Factors; Treatment Outcome
• ISSN: 0036-5548; 1651-1980
• DOI: 10.1080/00365540500372846

Staphylococcus aureus bacteremia often persists. The reasons for persistence and its outcome are poorly defined. We conducted a prospective-observational study among 245 consecutive S. aureus (MRSA: n=125; MSSA: n=120) bacteremias (≥1 positive blood cultures (BC)) among 234 adults (18-103-y-old; median = 59 y) hospitalized during 1 January 2002-31 December 2002 at a 600-bed teaching hospital. Measurements included bacteremia duration, complication-rate (metastatic infection, relapse or attributable mortality) and outcome. Bacteremia duration was measured based on follow-up BC among 193 patients and estimated based on symptoms resolution in the rest. Measured (1-59 d; median = 2) and estimated (median = 1 d) duration correlated (r=0.885) though positive follow-up BC was often detected without fever (57/105 patients, 54.3%). Persistence (defined as bacteremia for ≥3 d) was noted in 84 cases (38.4%). Complication-rate increased steadily with bacteremia duration (6.6%, 24.0% and 37.7% in bacteremia for 1-2, 3 and ≥4 d, respectively; p=0.05). Cox regression analysis revealed that bacteremia duration correlated positively with endovascular sources (p=0.006), vancomycin treatment (p=0.016), cardiovascular prosthesis (p=0.025), metastatic infections (p=0.025) and diabetes (p=0.038). It is concluded that persistent bacteremia is a feature of S. aureus infection, irrespective of oxacillin susceptibility, associated with worse outcome. Risk factors include endovascular sources, cardiovascular prosthesis, metastatic infections, vancomycin treatment and diabetes. Patients at risk may benefit from novel treatment strategies.