Search

Background: Staphylococcus aureus is a common cause of disease, particularly in colonized persons. Although methicillin-resistant S. aureus (MRSA) infection has become increasingly reported, population-based S. aureus and MRSA colonization estimates are lacking., Methods: Nasal samples for S. aureus culture and sociodemographic data were obtained from 9622 persons > or = 1 year old as part of the National Health and Nutrition Examination Survey, 2001-2002. After screening for oxacillin susceptibility, MRSA and selected methicillin-susceptible S. aureus isolates were tested for antimicrobial susceptibility, pulsed-field gel electrophoresis clonal type, toxin genes (e.g., for Panton-Valentine leukocidin [PVL]), and staphylococcal cassette chromosome mec (SCCmec) type I-IV genes., Results: For 2001-2002, national S. aureus and MRSA colonization prevalence estimates were 32.4% (95% confidence interval [CI], 30.7%-34.1%) and 0.8% (95% CI, 0.4%-1.4%), respectively, and population estimates were 89.4 million persons (95% CI, 84.8-94.1 million persons) and 2.3 million persons (95% CI, 1.2-3.8 million persons), respectively. S. aureus colonization prevalence was highest in participants 6-11 years old. MRSA colonization was associated with age > or = 60 years and being female but not with recent health-care exposure. In unweighted analyses, the SCCmec type IV gene was more frequent in isolates from participants of younger age and of non-Hispanic black race/ethnicity; the PVL gene was present in 9 (2.4%) of 372 of isolates tested., Conclusions: Many persons in the United States are colonized with S. aureus; prevalence rates differ demographically. MRSA colonization prevalence, although low nationally in 2001-2002, may vary with demographic and organism characteristics.

Methicillin-resistant Staphylococcus aureus (MRSA) is increasingly a cause of nosocomial and community-onset infection with unknown national scope and magnitude. We used the National Hospital Discharge Survey to calculate the number of US hospital discharges listing S. aureus-specific diagnoses, defined as those having at least 1 International Classification of Diseases (ICD)-9 code specific for S. aureus infection. The number of hospital discharges listing S. aureus-specific diagnoses was multiplied by the proportion of methicillin resistance for each corresponding infection site to determine the number of MRSA infections. From 1999 to 2000, an estimated 125,969 hospitalizations with a diagnosis of MRSA infection occurred annually, including 31,440 for septicemia, 29,823 for pneumonia, and 64,706 for other infections, accounting for 3.95 per 1,000 hospital discharges. The method used in our analysis may provide a simple way to assess trends of the magnitude of MRSA infection nationally.

Background and Objective: In August 2001, a cluster of MRSA skin infections was detected in a correctional facility. An investigation was conducted to determine its cause and to prevent further MRSA infections., Design: Case-control study., Setting: A 200-bed detention center., Patients: A case was defined as a detainee with a skin lesion from which MRSA was cultured from July 24 through December 31, 2001. Case-patients were identified by review of laboratory culture results and by skin lesion screening through point-prevalence survey and admission examination. Controls were randomly selected from an alphabetized list of detainees., Intervention: Medical staff implemented measures to improve skin disease screening, personal hygiene, wound care, and antimicrobial therapy., Results: Sixteen cases were identified: 11, 5, and 0 in the preintervention, peri-intervention, and postintervention periods, respectively. Seven case-patients and 19 controls were included in the case-control study. On multivariable analysis, working as a dormitory orderly (OR, 9.8; CI95, 0.74-638; P = .10) and a stay of longer than 36 days (OR, 6.9; CI95, 0.65-128.2; P = .14) were the strongest predictors for MRSA skin infection. The preintervention, peri-intervention, and postintervention MRSA infection rates were 11.6, 8.8, and 0 per 10,000 detainee-days, respectively. The rate of MRSA skin infections declined significantly between both the preintervention and peri-intervention periods and the postintervention period (P < .01 for both comparisons)., Conclusions: MRSA skin disease can become an emergent problem in a correctional facility. Interventions targeted at skin disease screening, appropriate antimicrobial treatment, and hygiene may decrease the risk of acquiring MRSA infection in correctional facilities.

Factors that affect the resistance rates for an organism-drug combination in a given hospital also might influence resistance rates for other organism-drug combinations. We examined correlations between resistance prevalence in non-intensive care inpatient areas of 41 hospitais participating in phase 3 (1998-1999) of Project ICARE (Intensive Care Antimicrobial Resistance Epidemiology). We focused on statistically significant (P < .05) Pearson correlation coefficients for methicillin-resistant Staphylococcus aureus, coagulase-negative staphylococci, vancomycin-resistant enterococci, and resistance to third-generation cephalosporins, imipenem, and fluoroquinolones in Escherichia coli, Klebsiella pneumoniae, Enterobacter species, and Pseudomonas aeruginosa. Resistance prevalence rates in individual hospitais were not strongly correlated among gram-positive organisms, and few correlations were seen between rates in gram-positive and gram-negative organisms. More frequent significant associations were found among resistance rates for gram-negative organisms. Resistance to third-generation cephalosporins in K. pneumoniae was significantly correlated with the majority of other sentinel antimicrobial-resistant organisms. High prevalence of this organism may serve as a marker for more generalized resistance problems in hospital inpatient areas. [ABSTRACT FROM AUTHOR]