C. Glen Mayhall

Vancomycin-Resistant Enterococci

After they were first identified in the mid-1980s, vancomycin-resistant enterococci (VRE) spread rapidly and became a major problem in many institutions both in Europe and the United States. Since VRE have intrinsic resistance to most of the commonly used antibiotics and the ability to acquire resistance to most of the current available antibiotics, either by mutation or by receipt of foreign genetic material, they have a selective advantage over other microorganisms in the intestinal flora and pose a major therapeutic challenge. The possibility of transfer of vancomycin resistance genes to other gram-positive organisms raises significant concerns about the emergence of vancomycin-resistant Staphylococcus aureus. We review VRE, including their history, mechanisms of resistance, epidemiology, control measures, and treatment.

The Epidemiology of Burn Wound Infections: Then and Now

Burn wound infections are a serious complication of thermal injury. Although pneumonia is now the most important infection in patients with burns, burn wound infection remains a serious complication unique to the burn recipient. The methods for managing thermal injury have evolved during the past 50 years. This evolution has been accompanied by changes in the etiology, epidemiology, and approach to prevention of burn wound infections. In the 1950s, 1960s, and 1970s and into the mid-1980s, burn wounds were treated by the exposure method, with application of topical antimicrobials to the burn wound surface and gradual debridement with immersion hydrotherapy. As early burn wound excision and wound closure became the focal point of burn wound management, accompanied by a change from immersion hydrotherapy to showering hydrotherapy, the rate of burn wound infection appeared to decrease. Few epidemiologic studies have been done since this change in the approach to management of thermal injury. There are few data on the epidemiology of burn wound infections from the era of early excision and closure. Data are needed on infection rates for excised and closed burn wounds, the etiologies of these infections, and the epidemiology and the prevention of such infections. Additional studies are needed on the indications for topical and antimicrobial prophylaxis and selective decontamination of the digestive tract.

Nosocomial Sinusitis in Patients in the Medical Intensive Care Unit: A Prospective Epidemiological Study

A prospective observational cohort study of nosocomial sinusitis was carried out in two medical intensive care units. Sinusitis was diagnosed by computed tomographic scanning and the culture of sinus fluid obtained by puncture of a maxillary sinus. Clinical and epidemiological data were collected at the time of admission to the unit and daily thereafter. Specimens from the nares, oropharynx, trachea, and stomach were cultured on admission and daily thereafter. The cumulative incidence of nosocomial sinusitis was 7.7%, and the incidence rates were 12 cases per 1,000 patient-days and 19.8 cases per 1,000 nasoenteric tube-days. Risk factors for nosocomial sinusitis, as determined by multiple logistic regression analysis, included nasal colonization with enteric gram-negative bacilli (odds ratio [OR], 6.4; 95% confidence interval [95% CI], 2.2-18.8; P = .007), feeding via nasoenteric tube (OR, 14.1; 95% CI, 1.7-117.6; P = .015), sedation (OR, 15.9; 95% CI, 1.9-133.5; P = .011), and a Glasgow coma score of < or = 7 (OR, 9.1; 95% CI, 3.0-27.3; P = .0001).

Epidemiology of methicillin-resistant Staphylococcus aureus in a university medical center day care facility.

OBJECTIVE Few data are available on methicillin-resistant Staphylococcus aureus (MRSA) colonization in day care. We performed a study in a medical university child care center to study the epidemiology of MRSA in this population. DESIGN Survey. SETTING A child care center on the campus of a university medical center. METHODS One hundred four children who attended the child care center and 32 employees gave samples that were cultured for MRSA. Seventeen household members of the children and employee found to be colonized with MRSA also gave samples that were cultured. Parents and employees completed questionnaires about demographic characteristics, medical conditions and treatments, and possible exposure risks outside the child care center. In addition, 195 environmental samples were taken from sites at the childcare center. Isolates were analyzed for relatedness by use of molecular typing, and statistical analysis was performed. RESULTS The prevalence of MRSA in the children was 6.7%. One employee (3.1%) was colonized with MRSA. Cultures of samples given by 6 of 17 (35.3%) family members of these children and the employee yielded MRSA. MRSA was recovered from 4 of 195 environmental samples. Molecular typing revealed that many of the MRSA isolates were indistinguishable, and 18 of the 21 isolates were community-associated MRSA. Multivariable analysis revealed that receipt of macrolide antibiotics (P = .002; odds ratio, 39.6 [95% confidence interval, 3.4-651.4]) and receipt of asthma medications (P = .024; odds ratio, 26.9 [95% confidence interval, 1.5-500.7]) were related to MRSA colonization. CONCLUSIONS There was a low prevalence of MRSA colonization in children and employees in the child care center but a higher prevalence of colonization in their families. Molecular typing showed that transmission of MRSA likely occurred in the child care center. The use of macrolide antibiotics and asthma medications may increase the risk of MRSA colonization in this population.

Control of vancomycin-resistant enterococci: it is important, it is possible, and it is cost-effective.

Clinical isolates of enterococci resistant to vancomycin were first detected in Europe in 1986 and reported in 1988. By 1989, vancomycin-resistant enterococci (VRE) were being recovered from cultures of clinical specimens in the United States, and by 1993, VRE made up 7.9% of nosocomial enterococci reported by hospitals in the National Nosocomial Infections Surveillance System of the Centers for Disease Control and Prevention (CDC). In the past decade, VRE have spread throughout the country, and the only places where they have not been found are probably in places where no one has looked. Although work remains to be done, the epidemiology of nosocomial VRE is well understood. The most important reservoir is the colonized gastrointestinal tracts of patients. VRE are transmitted between patients by the contaminated hands and clothes of healthcare workers and perhaps indirectly from contamination of the environment, particularly when at least one patient has diarrhea. VRE have been shown to survive for prolonged periods of time in the environment, and an outbreak in a burn unit recurred after 5 weeks from an electrocardiogram lead that had been contaminated by a colonized patient 38 days before VRE was cultured from the lead on the second patient.^ Risk factors for acquisition of VRE include treatment with vancomycin and cephalosporins, receipt of enteral feedings, sucralfate, or antacids, colonization pressure, and proximity to previously unisolated patients with VRE.

Effect of Gastrointestinal Bleeding and Oral Medications on Acquisition of Vancomycin-Resistant Enterococcus faecium in Hospitalized Patients

There has been minimal investigation of medications that affect gastrointestinal function as potential risk factors for the acquisition of vancomycin-resistant enterococci (VRE). We performed a retrospective case-control study, with control subjects matched to case patients by time and location of hospitalization. Strict exclusion criteria were applied to ensure that only case patients with a known time of acquisition of VRE were included. Control patients were patients with > or =1 culture negative for VRE. The risk factors identified were use of vancomycin (odds ratio [OR], 3.2; 95% confidence interval [CI], 1.7-6.0; P=.0003), presence of central venous lines (OR, 2.2; 95% CI, 1.04-4.6; P=.04), and use of antacids (OR, 2.9; 95% CI, 1.5-5.6; P=.002). Two protective factors included gastrointestinal bleeding (OR, 0.26; 95% CI, 0.08-0.79; P=.02) and use of Vicodin (Knoll Labs; hydrocodone and acetaminophen; OR, 0.93; 95% CI, 0.90-0.97; P=.0003). Changes in gastrointestinal function, whether due to bleeding or to the effects of oral medications, may affect whether patients become colonized with VRE.

Hospital Infection Prevention and Control Issues Relevant to Extensive Floods

The devastating clinical and economic implications of floods exemplify the need for effective global infection prevention and control (IPC) strategies for natural disasters. Reopening of hospitals after excessive flooding requires a balance between meeting the medical needs of the surrounding communities and restoration of a safe hospital environment. Postflood hospital preparedness plans are a key issue for infection control epidemiologists, healthcare providers, patients, and hospital administrators. We provide recent IPC experiences related to reopening of a hospital after extensive black-water floods necessitated hospital closures in Thailand and the United States. These experiences provide a foundation for the future design, execution, and analysis of black-water flood preparedness plans by IPC stakeholders.

Statement of the Fourth International Consensus Conference in critical care on ICU-acquired pneumonia

Scientific Advisors Christian Brun Bruisson (Paris, France), Waldemar Johanson (New Jersey, USA); International Consensus Conference Committee ATS: Catherine Sassoon (Long Beach, CA, USA), Brian Kavanagh (Toronto, Canada); ERS: Marc Elliott (Leeds, UK) ESICM: Graham Ramsay (Maastricht, Netherlands), Marco Ranieri (Turino, Italy); SRLF: Didier Dreyfuss (Paris, France), Jordi Mancebo (Barcelona, Spain). Scientific Experts: Edward Abraham; (Denver, USA), Massimo Antonelli, (Roma, Italy), Robert P Baughman; Cincinnati, USA, Marc Bonten; Utrecht, Netherland, Lucca Brazzi; Italy, Jean Chastre; Paris, France, Deborah Cook; Hamilton, Canada, Donald E Craven; Boston, USA, Lisa L, Dever; New Jersey, USA, Didier Dreyfuss; Colombes, France, Mahmoud Eltorky, Memphis, USA, Jean-Yves Fagon; Paris, France, Jesse Hall; Chicago, USA, Alan M Fein; Manhasset, USA, Dean Hess; Boston, USA, Steven H Kirtland; Seattle, USA, Marin H Kollef; St. Louis, USA, Lionel A Mandell; Hamilton, Canada, Charles H Marquette; Lille, France, Thomas R Martin; Seattle, USA, C Glen Mayhall; Galveston, USA, G Umberto Meduri; Memphis, USA, Dominique L Monnet; Copenhagen, Denmark, Michael S Niederman; Mineola, USA, Jerome Pugin; Geneva, Switzerland, Theodore J Standiford; Michigan, USA, Jordi Rello; Tarragona, Spain, Jean-Francois Timsit; Paris, France, Antonio Torres; Barcelona, Spain, Robert Weinstein; Chicago, USA, Richard Wunderink; Memphis, USA. On May 23-24, 2002, in Chicago Illinois, a jury of eleven intensivists heard expert testimony that was intended to answer five specific questions: 1) What is the epidemiology of ICU-Acquired pneumonia; 2) What are the pathophysiological characteristics and pathogenesis of ICU-acquired pneumonia; 3) What are the Risk Factors and Effective Preventive Measures for ICU-Acquired Pneumonia; 4) What is the best means to establish a Diagnosis of ICU-Acquired Pneumonia; and 5) What are the Optimal Therapeutic Approaches to ICU-Acquired Pneumonia. The following is a synopsis of the expert testimony, the jury’s interpretation of the testimony and their recommendations.

Epidemiology of Methicillin-Susceptible Staphylococcus aureus in a University Medical Center Day Care Facility

Background: Few data are available on methicillin-susceptible Staphylococcus aureus (MSSA) colonization in day care. We performed a study in a child care center on a medical university campus to study the epidemiology of MSSA in this population. Methods: A cross-sectional study was done on 104 day care attendees and 32 adult employees of the child care center. Swab samples were taken from the nose, oropharynx, axilla, groin, and perirectal area of children, from the nose and oropharynx of employees, and from the environment. Parents and employees completed questionnaires. Swabs were placed in broth, then plated on agar and identified as MSSA by routine methods. Molecular typing was performed. Results: The prevalence of MSSA was 21.15% in children and 28.13% in employees. MSSA was found in 8.72% of environmental samples. Univariate analysis identified 3 risk factors and 5 protective factors for MSSA colonization. In multivariable analysis, only 2 variables remained significantly related to MSSA colonization, with older age remaining as a risk factor and receipt of beta-lactams approaching significance as being protective. Many of the isolates were indistinguishable by molecular typing. Conclusions: The prevalence of MSSA colonization in children and care providers in a university medical center child care center is similar to that of the general population. Children colonized with MSSA tended to be older and to have received fewer courses of antibiotics than children who did not have MSSA. The relatedness of many of the isolates indicates that transmission of MSSA occurred at this child care center.

Nosocomial Colonization and Its Impact on Hospital-Acquired Infections

We are pleased to bring to our readership the contents of a symposium on nosocomial colonization held on January 14-16, 1994, in Clearwater, Florida, under the aegis of the University of South Florida College of Medicine and the National Foundation for Infectious Diseases. The symposium was developed with the following goals: (1) to provide an up-to-date overview of the factors important in microbial colonization of human nonsterile surfaces or tissues, especially skin, nose, oropharynx, and gastrointestinal tract; (2) to provide an understanding of the impact of colonization upon the development of nosocomial infections; and (3) to provide an appreciation of how to control or manage colonization to prevent nosocomial infections. The following article on the molecular biology of bacterial colonization by Alan L. Bisno, MD, is the first of six papers from this symposium to be published in consecutive issues of Infection Control and Hospital Epidemiology. The papers will be published in the same order in which they were presented at the symposium. Articles to follow will cover the epidemiology of colonization, the microbiology of colonization, the role of colonization in the pathogenesis of nosocomial infections, treatment and control of colonization, and colonization and nosocomial infections in human immunodeficiency virus-infected patients. This program was supported in part by a grant from Smith-Kline Beecham to the National Foundation for Infectious Diseases.