The anterior nares are the most sensitive single site for detecting methicillin-resistant Staphylococcus aureus (MRSA) colonization. Colonization patterns of USA300 MRSA colonization are unknown.

To assess whether residents of extended care facilities who are colonized with USA300 MRSA have different nares or skin colonization findings, compared with residents who are colonized with non-USA300 MRSA strains.

The study population included residents of 5 extended care units in 3 separate facilities who had a recent history of MRSA colonization. Specimens were obtained weekly for surveillance cultures from the anterior nares, perineum, axilla, and skin breakdown (if present) for 3 weeks. MRSA isolates were categorized as USA300 MRSA or non-USA300 MRSA.

Of the 193 residents who tested positive for MRSA, 165 were colonized in the anterior nares, and 119 were colonized on their skin. Eighty-four percent of USA300 MRSA-colonized residents had anterior nares colonization, compared with 86% of residents colonized with non-USA300 MRSA (P = .80). Sixty-six percent of USA300 MRSA–colonized residents were colonized on the skin, compared with 59% of residents colonized with non-USA300 MRSA (P = .30).

Colonization patterns of USA300 MRSA and non-USA300 MRSA are similar in residents of extended care facilities. Anterior nares cultures will detect most—but not all—people who are colonized with MRSA, regardless of whether it is USA300 or non-USA300 MRSA.

To characterize the epidemiology and microbiology of ventilator-associated pneumonia (VAP) in a long-term acute care hospital (LTACH).

Retrospective study of prospectively identified cases of VAP.

Single-center, 207-bed LTACH with the capacity to house 42 patients requiring mechanical ventilation, evaluated from April 1, 2006, through January 31, 2008.

Data on the occurrence of VAP were collected prospectively as part of routine infection surveillance at Radius Specialty Hospital. After March 2006, Radius Specialty Hospital implemented a bundle of interventions for the prevention of VAP (hereafter referred to as the VAP-bundle approach). A case of VAP was defined as a patient who required mechanical ventilation at Radius Specialty Hospital for at least 48 hours before any symptoms of pneumonia appeared and who met the Centers for Disease Control and Prevention criteria for VAP. Sputum samples were collected from a tracheal aspirate if there was clinical suspicion of VAP, and these samples were semi-quantitatively cultured.

During the 22-month study period, 23 cases of VAP involving 19 patients were associated with 157 LTACH admissions (infection rate, 14.6%), corresponding to a rate of 1.67 cases per 1,000 ventilator-days, which is a 56% reduction from the VAP rate of 3.8 cases per 1,000 ventilator-days reported before the implementation of the VAP-bundle approach (P<.001). Microbiological data were available for 21 (91%) of 23 cases of VAP. Cases of VAP in the LTACH were frequently polymicrobial (mean number ± SD, 1.78 ± 1.0 pathogens per case of VAP), and 20 (95%) of 21 cases of VAP had at least 1 pathogen (Pseudomonas species, Acinetobacter species, gram-negative bacilli resistant to more than 3 antibiotics, or methicillin-resistant Staphylococcus aureus) cultured from a sputum sample. LTACH patients with VAP were more likely to have a neurological reason for ventilator dependence, compared with LTACH patients without VAP (69.6% of cases of VAP vs 39% of cases of respiratory failure; P = .014). In addition, patients with VAP had a longer length of LTACH stay, compared with patients without VAP (median length of stay, 131 days vs 39 days; P = .002). In 6 (26%) of 23 cases of VAP, the patient was eventually weaned from use of mechanical ventilation. Of the 19 patients with VAP, 1 (5%) did not survive the LTACH stay.

The VAP rate in the LTACH is lower than the VAP rate reported in acute care hospitals. Cases of VAP in the LTACH were frequently polymicrobial and were associated with multidrug-resistant pathogens and increased length of stay. The guidelines from the Centers for Disease Control and Prevention that are aimed at reducing cases of VAP appear to be effective if applied in the LTACH setting.

Multidrug-resistant (MDR) gram-negative bacteria are reported increasingly frequently among isolates recovered from elderly patients. The clinical epidemiology of bloodstream infection (BSI) due to MDR gram-negative bacteria among elderly patients is unknown.

To characterize the clinical epidemiology of BSI due to MDR gram-negative bacteria among elderly patients at hospital admission in an effort to provide a greater understanding of these serious infections and ultimately to improve patient outcomes.

Case-control study.

Tertiary care hospital in Boston, Massachusetts.

Patients 65 years of age and older.

From 1999 to 2007, computerized medical records were reviewed for BSI due to MDR gram-negative bacteria within 48 hours of hospital admission. Risk factors for BSI due to these bacteria were identified.

MDR gram-negative bacteria were recovered from 61 (8%) of 724 elderly patients with BSI caused by gram-negative bacteria. Over the -year study period, the percentage of MDR gram-negative bacteria among bloodstream isolates increased from 2 (1%) of 199 to 34 (16%) of 216. Empiric therapy was ineffective for 38 (63%) of 60 patients with BSI caused by MDR gram-negative bacteria. The variables independently associated with BSI due to these bacteria were as follows: residency in a long-term care facility (odds ratio [OR], 4.9 [95% confidence interval {CI} 1.6–14.9]; P = .006), presence of an invasive device (OR, 6.0 [95% CI, 1.5–23.5]; P = .01), severe sepsis (OR, 7.9 [95% CI, 1.7–37.1]; P = .009), and delayed initiation of effective therapy (OR, 12.8 [95% CI, 3.9–41.1]; P<.001).

The 16-fold increase in BSI due to MDR gram-negative bacteria at hospital admission among elderly patients, especially among those who resided in long-term care facilities prior to admission, contributes further to the expanding body of evidence that these patients are the main reservoirs of MDR gram-negative bacteria. Given their contribution to the influx of antimicrobial-resistant bacteria in the hospital setting, infection control interventions that target this high-risk group need to be considered.

To compare Clostridium difficile infection (CDI) rates determined with use of a traditional definition (ie, with healthcare-onset CDI defined as diagnosis of CDI more than 48 hours after hospital admission) with rates determined with use of expanded definitions, including both healthcare-onset CDI and community-onset CDI, diagnosed within 48 hours after hospital admission in patients who were hospitalized in the previous 30 or 60 days, and to determine whether differences exist between patients with CDI onset in the community and those with CDI onset in a healthcare setting.

Prospective cohort

Tertiary acute care facility.

General medicine patients who received a diagnosis of CDI during the period January 1, 2004, through December 31, 2005.

CDI was classified as healthcare-onset CDI, healthcare facility–associated CDI after hospitalization within the previous 30 days, and/or healthcare facility-associated CDI after hospitalization within the previous 60 days. Patient demographic characteristics and medication exposures were obtained. The CDI incidence with use of each definition, CDI rate variability, patient demographic characteristics, and medication exposures were compared.

The healthcare-onset CDI rate (1.6 cases per 1,000 patient-days) was significantly lower than the 30-day healthcare facility–associated CDI rate (2.4 cases per 1,000 patient-days; P<.01) and the 60-day healthcare facility–associated CDI rate (2.6 cases per 1,000 patient-days; P<.01). There was good correlation between the healthcare-onset CDI rate and both the 30-day (correlation, 0.69; P<.01) and 60-day (correlation, 0.70; P<.01) healthcare facility–associated CDI rates. There were no months in which the CDI rate was more than 3 standard deviations from the mean. Compared with patients with healthcare-onset CDI, patients with community-onset CDI were less likely to have received a fourth-generation cephalosporin (P = .02) or intravenous vancomycin (P = .01) during hospitalization.

Compared with the traditional definition, expanded definitions identify more patients with CDI. There is good correlation between traditional and expanded CDI definitions; therefore, it is unclear whether expanded surveillance is necessary to identify an abnormal change in CDI rates. Cases that met the expanded definitions were less likely to have occurred in patients with fourth-generation cephalosporin and vancomycin exposure.

To detect the burden of vancomycin-resistant Enterococcus (VRE) colonization among pediatric oncology patients and to determine risk factors for VRE acquisition.

Retrospective case-control study.

The Children's Hospital of Philadelphia.

Pediatric oncology patients hospitalized from June 2006 through December 2007.

Prevalence surveys revealed an increased VRE burden among pediatric oncology patients. For the case-control study, the 16 case patients were pediatric oncology patients who had 1 stool sample negative for VRE at screening before having a stool sample positive for VRE at screening; the 62 control patients had 2 consecutive screenings in which stool samples were negative for VRE. Case and control patients were matched on the duration of the interval between screens. Analyses were performed to determine the association between multiple exposures and VRE acquisition.

The prevalence survey revealed that 5 (9.6%) of 52 patients had unsuspected VRE colonization at the time of hospitalization. Multivariate analysis identified a lack of empirical contact precautions (odds ratio [OR], 17.16 [95% confidence interval {CI}, 1.49–198.21]; P = .02) and the presence of a gastrointestinal device (OR, 4.03 [95% CI, 1.04–15.56]; P = .04) as significant risk factors for acquisition of VRE. Observations in the interventional radiology department revealed that staff could not access the portions of the electronic medical record in which isolation precautions were documented. Simple interventions that granted access and that trained interventional radiology staff to review the need for precautions, coupled with enhanced infection control practices, interrupted ongoing transmission and reduced the proportion of VRE screens that were positive to 15 (1.2%) of 1,270.

Inadequate communication with regard to infection control precautions can increase the risk of transmission of epidemiologically important organisms, particularly when patients receive care at multiple clinic locations. Adherence to infection control practices across the spectrum of care may limit the spread of resistant organisms.

To determine the impact of antibiotic consumption and alcohol-based hand disinfection on the incidences of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infection and Clostridium difficile infection (CDI).

Two multivariate time-series analyses were performed that used as dependent variables the monthly incidences of nosocomial MRSA infection and CDI at the Freiburg University Medical Center during the period January 2003 through October 2007. The volume of alcohol-based hand rub solution used per month was quantified in liters per 1,000 patient-days. Antibiotic consumption was calculated in terms of the number of defined daily doses per 1,000 patient-days per month.

The use of alcohol-based hand rub was found to have a significant impact on the incidence of nosocomial MRSA infection (P<.001). The multivariate analysis (R2 = 0.66) showed that a higher volume of use of alcohol-based hand rub was associated with a lower incidence of nosocomial MRSA infection. Conversely, a higher level of consumption of selected antimicrobial agents was associated with a higher incidence of nosocomial MRSA infection. This analysis showed this relationship was the same for the use of second-generation cephalosporins (P = .023), third-generation cephalosporins (P = .05), fluoroquinolones (P = .01), and lincosamides (P = .05). The multivariate analysis (R2 = 0.55) showed that a higher level of consumption of third-generation cephalosporins (P = .008), fluoroquinolones (P = .084), and/or macrolides (P = .007) was associated with a higher incidence of CDI. A correlation with use of alcohol-based hand rub was not detected.

In 2 multivariate time-series analyses, we were able to show the impact of hand hygiene and antibiotic use on the incidence of nosocomial MRSA infection, but we found no association between hand hygiene and incidence of CDI.

To investigate a large outbreak of scabies in an intensive care unit of a university hospital and an affiliated rehabilitation center, and to establish effective control measures to prevent further transmission.

Outbreak investigation.

The intensive care unit of a 750-bed university hospital and an affiliated 92-bed rehabilitation center.

All exposed individuals were screened by a senior staff dermatologist. Scabies was diagnosed on the basis of (1) identification of mites by skin scraping, (2) identification of mites by dermoscopy, or (3) clinical examination of patients without history of prior treatment for typical burrows. During a follow-up period of 6 months, the attack rate was calculated as the number of symptomatic individuals divided by the total number of exposed individuals.

All exposed healthcare workers (HCWs) and their household members underwent preemptive treatment. Initially, the most effective registered drug in Switzerland (ie, topical lindane) was prescribed, but this prescribption was switched to topical permethrin or systemic ivermectin as a result of the progression of the outbreak. Individuals with any signs or symptoms of scabies underwent dermatological examination.

Within 7 months, 19 cases of scabies were diagnosed, 6 in children with a mean age of 3.1 years after exposure to the index patient with HIV and crusted scabies. A total of 1,640 exposed individuals underwent preemptive treatment. The highest attack rate of 26%–32% was observed among HCWs involved in the care of the index patient. A too-restricted definition of individuals at risk, non-compliance with treatment, and the limited effectiveness of lindane likely led to treatment failure, relapse, and reinfestation within families.

Crusted scabies resulted in high attack rates among HCWs and household contacts. Timely institution of hygienic precautions with close monitoring and widespread, simultaneous scabicide treatment of all exposed individuals are essential for control of an outbreak.

To describe the method used to develop a flexible, computerized database for recording and reporting rates of influenza vaccination among healthcare personnel who were classified by their individual levels (hereafter, “tiers”) of direct patient contact.

Three-year descriptive summary.

Large, academic, tertiary care medical center in the United States.

All of the medical center's healthcare personnel.

The need to develop a computer-based system to record direct patient care tiers and vaccination data for healthcare personnel was identified. A plan that was to be implemented in stages over several seasons was developed.

Direct patient care tiers were defined by consensus opinion on the basis of the extent, frequency, and intensity of direct contact with patients. The definitions of these tiers evolved over 3 seasons. Direct patient care classifications were assigned and recorded in a computerized database, and data regarding the receipt of vaccination were tracked by using the same database. Data were extracted to generate reports of individual, departmental, and institutional vaccination rates, both overall and according to direct patient care tiers.

Development of a computerized database to record direct patient care tiers for individual healthcare workers is a daunting but manageable task. Widespread use of these direct patient care definitions will facilitate uniform comparisons of vaccination rates between institutions. This computerized database can easily be used by infection control personnel to accomplish several other key tasks, including vaccination triage in the context of shortage or delay, prioritization of personnel to receive interventions in times of crisis, and monitoring the status of other employee health or occupational health measures.

During fall 2005, personal stockpiling of oseltamivir for use during an outbreak of H5N1 influenza virus infection was widely reported. The present study aimed to identify indications for oseltamivir prescriptions to determine whether oseltamivir that was not intended for seasonal influenza was inappropriately consumed and to compare persons who were likely to have stockpiled oseltamivir and those who did not with respect to their knowledge, understanding, concerns, and expectations regarding avian influenza.

Survey to evaluate usage patterns for oseltamivir and assess views about avian influenza.

A total of 109 outpatients who received a prescription for oseltamivir between September 1, 2005, and December 31, 2005, and 825 matched control subjects.

Of 109 prescriptions, 36 (33.0%) were prescribed for patients with appropriate indications. Sixty-eight (62.4%) of 109 patients identified as having received oseltamivir and 440 (53.3%) of 825 individuals identified as not having received it responded to the questionnaire. Only 2 prescription recipients whose oseltamivir was not intended for immediate consumption reported that they had consumed the oseltamivir. Persons who probably intended to stockpile oseltamivir were older and more often white than those unlikely to stockpile it. They also reported greater worry about avian influenza and more often expected avian influenza to spread to the United States than those unlikely to stockpile, but there were no significant differences in responses to other questionnaire items.

A large proportion of the oseltamivir prescriptions written in fall 2005 were probably intended for personal stockpiling. Similarities in participants' responses to questionnaire items suggest that educational campaigns may not be an effective method to curtail stockpiling of antimicrobial medications during an infectious threat. Promoting appropriate prescribing practices among providers may be a better means by which to minimize personal stockpiling.