Characteristics of invasive Staphylococcus aureus infections in three regions of Korea, 2009-2011: a multi-center cohort study

Abstract

BackgroundDespite the importance of invasive Staphylococcus aureus (ISA) infection, its overall burden in non-selected populations has only been defined in a small number of studies in Europe and North America. To define the characteristics of ISA infections in Korea, we conducted a multi-center cohort study to estimate population-based incidence rates.MethodsWe conducted a multicenter prospective cohort study at nine university-affiliated active-surveillance core centers (ASCs) in three regions of Korea. To cover all available clinical microbiologic laboratories, we classified the laboratories in these regions into three groups according to their clinical environment as: 1) Nine ASCs, 2) Five major commercial laboratories and 3) Forty-four acute-care hospital-affiliated microbiology laboratories. We requested all the laboratories to report prospectively their numbers of cases of S. aureus isolated from normally sterile sites. Detailed clinical information was collected about the cases in the nine ASCs.ResultsFrom 1 July 2009 to 30 June 2011, a total of 1,198 cases of ISA infection were identified at the nine ASCs, including 748 (62%) methicillin-resistant S. aureus (MRSA) infections. Most (81%) ISA infections were healthcare-associated (HCA): 653 (55%) hospital-onset and 322 (27%) community-onset. 223 (19%) were community-associated infections. The most common primary diagnosis was catheter-associated infection (225 cases, 19%). Respiratory tract infection (160, 13%), skin & soft tissue (152, 13%) and bone & joint infections (120, 10%) were also common. 30-day and 12-week mortality rates were 25.6% (262/1,024) and 36.5% (314/860), respectively. Complications, including metastatic infection within 12 weeks, occurred in 17.8% of ISA infections. The most common site of metastatic infection was the lung (9.8%, 84/860). Based on the total of 2,806 observed cases of ISA infection, estimated annual rates of ISA and invasive MRSA infections were 43.3 and 27.7 per 100,000 populations, respectively.ConclusionsOur data provide important information about the clinical characteristics of ISA infections. We estimate that over 21,000 ISA infections and 13,000 invasive MRSA infections occurred in Korea in 2010.

Impact of Vancomycin MIC on Treatment Outcomes in Invasive Staphylococcus aureus Infections

“…All adult patients (aged Ն15 years) with S. aureus isolated from normally sterile sites were identified prospectively both from clinical microbiology laboratories and by active surveillance on the part of infectious disease specialists in 10 hospitals over a 2-year period from 1 July 2009 to 30 June 2011; nine of the patients had participated in a previous cohort study (1). The patients' demographic characteristics, underlying diseases, infection sites, vital signs, and laboratory findings were examined.…”

“…nfections caused by Staphylococcus aureus are a major health problem in both hospital-acquired and community-associated settings (1). Invasive S. aureus (ISA) infections, defined as the isolation of S. aureus from a normally sterile site (e.g., bacteremia), are associated with high morbidity and mortality (1).…”

“…Invasive S. aureus (ISA) infections, defined as the isolation of S. aureus from a normally sterile site (e.g., bacteremia), are associated with high morbidity and mortality (1). Methicillin-resistant S. aureus (MRSA) accounts for about 60% of nosocomial S. aureus infections, and community-associated MRSA disease has been increasing in Korea (1,2). Although new antistaphylococcal antibiotics have been developed, vancomycin retains the first-line position as treatment for MRSA infections (3).…”

agr Dysfunction Affects Staphylococcal Cassette Chromosome mec Type-Dependent Clinical Outcomes in Methicillin-Resistant Staphylococcus aureus Bacteremia

“…Data for patient sex, age, onset of bacteremia, first positive blood culture in the intensive care unit (ICU), nosocomial or community acquisition of the bacteremia with a history of previous health care contact (30), primary site of infection, and antibiotic treatment were collected prospectively (31,32). The following data were retrospectively reviewed for this study: Charlson's comorbidity weighted index (33), the McCabe and Jackson classification of underlying illness (classified as rapidly fatal when death was expected within days or weeks, ultimately fatal when death was expected within months or years, and nonfatal when death was not expected), steroid use (equivalent to 20 mg of prednisolone per day Ն1 week) or chemotherapy within 30 days, presence of neutropenia (absolute neutrophil count, Ͻ500/l), severity of illness as measured by the Pitt bacteremia score (34) and sequential organ failure assessment (SOFA) score (35), presentation with septic shock, eradication of the infection foci, and in-hospital death.…”

Clinical and Molecular Characterization of Invasive Heteroresistant Vancomycin-Intermediate Staphylococcus aureus Infections in Korean Hospitals

“…Ten hospitals in four Korean regions, nine of which participated in a previous cohort study (5), took part in this study from July 2009 to June 2011. ISA infection was diagnosed when S. aureus was isolated from a normally sterile body fluid, as previously defined (6).…”