Holly A. Hill

Prevalence of Staphylococcus aureus Nasal Colonization in the United States, 2001–2002

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 Hospitalizations, United States

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.

Temporal Changes in Prevalence of Antimicrobial Resistance in 23 U.S. Hospitals

Antimicrobial resistance is increasing in nearly all health-care–associated pathogens. We examined changes in resistance prevalence during 1996–1999 in 23 hospitals by using two statistical methods. When the traditional chi-square test of pooled mean resistance prevalence was used, most organisms appear to have increased in prevalence. However, when a more conservative test that accounts for changes within individual hospitals was used, significant increases in prevalence of resistance were consistently observed only for oxacillin-resistant Staphylococcus aureus, ciprofloxacin-resistant Pseudomonas aeruginosa, and ciprofloxacin- or ofloxacin-resistant Escherichia coli. These increases were significant only in isolates from patients outside intensive-care units (ICU). The increases seen are of concern; differences in factors present outside ICUs, such as excessive quinolone use or inadequate infection-control practices, may explain the observed trends.

Cycling empirical antimicrobial agents to prevent emergence of antimicrobial-resistant Gram-negative bacteria among intensive care unit patients

Objective:To determine the impact of the rotation of antimicrobial agents on the rates of infection, intestinal colonization, and acquisition with antimicrobial-resistant Gram-negative bacteria. Design:Pre- and postintervention design. Setting:A 19-bed, medical intensive care unit. Patients:Individuals admitted to the study unit for >48 hrs. Interventions:After a 5-month baseline observation period, four classes of antimicrobial agents with Gram-negative activity were cycled at 3- to 4-month intervals for 24 months. Measurements and Main Results:The primary outcome was the acquisition rate of antimicrobial resistance among Enterobacteriaceae and Pseudomonas aeruginosa obtained from rectal swab cultures performed on admission, weekly during the patients’ stay, and at discharge. Rates and microbiology of nosocomial bloodstream infections and ventilator-associated pneumonia were also compared between baseline and cycling periods. The cycling program resulted in a significant change in prescribing practices; the predominant agent used changed with each cycle. Among study patients who were not already colonized with a resistant organism, the rate of acquisition of enteric colonization with bacteria resistant to any of the target drugs remained stable during the cycling period for P. aeruginosa (relative rate, 0.96; 95% confidence Interval, 0.47–2.16) and Enterobacteriaceae (relative rate, 1.57; 95% confidence interval, 0.80–3.43). Hospital-wide, P. aeruginosa from routine clinical cultures resistant to the target drugs increased during the cycling period. The proportion of Gram-negative bacteria isolated from cases of nosocomial bloodstream infection (29% baseline vs. 26% cycling; p = .11) and ventilator-associated pneumonia (80% vs. 41%; p = .06) did not significantly differ. Conclusions:In this study, antimicrobial cycling did not result in a significant change in enteric acquisition of resistant Gram-negative bacteria among intensive care unit patients.

Intervention to Reduce the Incidence of Methicillin-Resistant Staphylococcus aureus Skin Infections in a Correctional Facility in Georgia

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.

Clinical Features that Discriminate Inhalational Anthrax from Other Acute Respiratory Illnesses

Inhalational anthrax (IA) is a rapidly progressive disease that frequently results in sepsis and death, and prompt recognition is critical. To distinguish IA from other causes of acute respiratory illness, patients who had IA were compared with patients in an ambulatory clinic who had influenza-like illness (ILI) and with hospitalized patients who had community-acquired pneumonia (CAP) at the initial health care visit. Compared with patients who had ILI, patients who had IA were more likely to have tachycardia, high hematocrit, and low albumin and sodium levels and were less likely to have myalgias, headache, and nasal symptoms. Scoring systems were devised to compare IA with ILI or CAP on the basis of strength of association. For ILI, a score of > or =4 captured all 11 patients with IA and excluded 664 (96.1%) of 691 patients with ILI. Compared with patients who had CAP, patients with IA were more likely to have nausea or vomiting, tachycardia, high transaminase levels, low sodium levels, and normal white blood cell counts. For CAP, a score of > or =3 captured 9 (81.8%) of 11 patients with IA and excluded 528 (81.2%) of 650 patients with CAP. In conclusion, selected clinical features of patients with IA differ from those of patients with ILI and are more similar to those of patients with CAP.

Progress Toward Eliminating Hepatitis A Disease in the United States

Hepatitis A virus (HAV) disease disproportionately affects adolescents and young adults, American Indian/Alaska Native and Hispanic racial/ethnic groups, and disadvantaged populations. During 1996-2006, the Advisory Committee on Immunization Practices (ACIP) made incremental changes in hepatitis A (HepA) vaccination recommendations to increase coverage for children and persons at high risk for HAV infection. This report examines the temporal association of ACIP-recommended HepA vaccination and disparities (on the absolute scale) in cases of HAV disease and on seroprevalence of HAV-related protection (measured as antibody to HAV [anti-HAV]). ACIP-recommended childhood HepA vaccination in the United States has eliminated most absolute disparities in HAV disease by age, race/ethnicity, and geographic area with relatively modest ≥1-dose and ≥2-dose vaccine coverage. However, the increasing proportion of cases of HAV disease among adults with identified and unidentified sources of exposure underscores the importance of considering new strategies for preventing HAV infection among U.S. adults. For continued progress to be made toward elimination of HAV disease in the United States, additional strategies are needed to prevent HAV infection among an emerging population of susceptible adults. Notably, HAV infection remains endemic in much of the world, contributing to U.S. cases through international travel and the global food economy.

Does Antimicrobial Resistance Cluster in Individual Hospitals

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 hospitals 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 hospitals 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.

Alcohol-associated injury visits to emergency departments in Pasto, Colombia in 2006.

Alcohol-associated injury visits to emergency departments in Pasto, Colombia in 2006 Victoria Espitia-Hardeman*, Dan Hungerford, Holly A. Hill, Carmen E. Betancourt, Alba N. Villareal, Luz D. Caycedo and Carlos Portillo Division of Violence Prevention, National Center for Injury Prevention and Control, Centers for Disease Control and Prevention, Atlanta, GA, USA; Division of Injury Response, National Center for Injury Prevention and Control, Centers for Disease Control and Prevention, Atlanta, GA, USA; Observatorio del Delito, Pasto, Colombia

Employment and Socioeconomic Factors Associated With Children's Up-to-Date Vaccination Status.

This study examined whether additional information on parents’ employment and household characteristics would help explain the differences in children’s up-to-date (UTD) vaccination status using the 2008 National Immunization Survey and its associated Socioeconomic Status Module. After controlling for basic sociodemographic factors in multivariable analyses, parent’s work schedules and ease of taking time off from work were not associated with UTD vaccination status among 19- to 35-month-old children. We also conducted a stratified analysis to test the heterogeneous effects of the factors among children at 3 age-restricted maternal education levels and found the benefit of paid sick leave had a significant association only among families where the mother had a college degree. Families who had moved since the child’s birth, especially if the mother had high school or lower education, were less likely to have children UTD on the vaccine series.