Epidemiology of Methicillin-ResistantStaphylococcus aureusand Vancomycin-ResistantEnterococcusin a Rural State

Staphylococcus aureus in the nose and throat of Iowan families

The study objective was to determine the prevalence of Staphylococcus aureus colonisation in the nares and oropharynx of healthy persons and identify any risk factors associated with such S. aureus colonisation. In total 263 participants (177 adults and 86 minors) comprising 95 families were enrolled in a year-long prospective cohort study from one urban and one rural county in eastern Iowa, USA, through local newspaper advertisements and email lists and through the Keokuk Rural Health Study. Potential risk factors including demographic factors, medical history, farming and healthcare exposure were assessed. Among the participants, 25.4% of adults and 36.1% minors carried S. aureus in their nares and 37.9% of adults carried it in their oropharynx. The overall prevalence was 44.1% among adults and 36.1% for minors. Having at least one positive environmental site for S. aureus in the family home was associated with colonisation (prevalence ratio: 1.34, 95% CI: 1.07-1.66). The sensitivity of the oropharyngeal cultures was greater than that of the nares cultures (86.1% compared with 58.2%, respectively). In conclusion, the nares and oropharynx are both important colonisation sites for healthy community members and the presence of S. aureus in the home environment is associated with an increased probability of colonisation.

Clostridium difficile-Associated Disease in Patients in a Small Rural Hospital

Objective.

To determine the risk factors for Clostridium difficile–associated disease (CDAD) in a 25-bed rural hospital and to compare antimicrobial use ratios at the study hospital with those at a large academic medical center.

Design.

Case-control study.

Setting.

A 25-bed rural hospital in Iowa during the period from August 2002 through January 2005.

Patients.

A total of 17 case patients with CDAD and 34 control patients matched for age (ie, within 10 years of the case patient's age), sex, and admission date (ie, within 2 weeks of the case patient's admission date).

Methods.

Retrospective medical record review was performed to obtain data on antimicrobial exposures during the 6 weeks before hospital admission for both case and control patients. Exact conditional logistic regression was used for univariable and multivariable analyses. Antimicrobial use ratios were calculated to compare the rates of antimicrobial use for case and control patients at the study hospital with the rates for patients evaluated in a study of CDAD at a nearly 700-bed teaching hospital.

Results.

Case patients had a larger cumulative number of days of antimicrobial use (P = .004), and they received a larger total number of antimicrobial agents during hospitalization (P = .001). Antimicrobial use ratios were higher for both case and control patients at the smaller hospital, compared with the larger hospital.

Conclusions.

CDAD at a small rural hospital was not associated with exposure to the antimicrobial classes that are typically associated with CDAD, but was instead related to the total number of antimicrobials used to treat patients. The rate of antimicrobial use for case and control patients was about 40% higher at the small rural hospital, compared with the corresponding rates at a large academic medical center.

Methicillin-resistant Staphylococcus aureus prevention practices in hospitals throughout a rural state

BACKGROUND

The Institute for Healthcare Improvement (IHI) created an evidence-based bundle to help reduce methicillin-resistant Staphylococcus aureus (MRSA) health care-associated infections. The study aim was to identify which components of the IHI's MRSA bundle that rural hospitals have implemented and to identify barriers that hindered implementation of bundle components.

METHODS

Four surveys about the IHI's MRSA bundle were administered at the Iowa Statewide Infection Prevention Seminar between 2007 and 2011. Surveys were mailed to infection preventionists (IPs) who did not attend the meetings.

RESULTS

The percentage of IPs reporting that their hospital implemented a hand hygiene program (range by year, 87%-94%) and used contact precautions for patients infected (range by year, 97%-100%) or colonized (range by year, 77%-92%) with MRSA did not change significantly. The number of hospitals that monitored the effectiveness of environmental cleaning significantly increased from 23%-71% (P < .01). Few hospitals assessed daily if central lines were necessary (range by year, 22%-26%). IPs perceived lack of support to be a major barrier to implementing bundle components.

CONCLUSION

Most IPs reported that their hospitals had implemented most components of the MRSA bundle. Support within the health care system is essential for implementing each component of an evidence-based bundle.

Microbial profile of diabetic foot infections in Trinidad and Tobago

AIMS

To examine the microbiologic profile of diabetic foot infections in order to guide empiric antibiotic choices.

METHODS

All patients with moderate-severe diabetic foot infections at a tertiary care facility were identified from July 2011 to June 2012. Culture samples were routinely collected before empiric antibiotics were commenced. Retrospective chart review was performed to extract the following data: demographics, clinical details, empiric antibiotic choice and microbiologic data. Descriptive analyses were performed using SPSS 12.0.

RESULTS

There were 139 patients at a mean age of 56.9 ± 12.4 years. Mixed poly-microbial infections were present in 56.8% of cases. Of 221 organisms isolated, 64.7% were gram-negative aerobes, 32.1% were gram-positive aerobes and 3.2% were obligate anaerobes. Multidrug resistant organisms were encountered in 25.9% of cases and included ESBL producers (11.3%), MRSA (4.5%) and VRE (1.4%). Both ciprofloxacin and ceftazidime had good overall anti-microbial activity against gram-negative (68% and 62%, respectively) and gram-positive pathogens (69% and 48%, respectively). Obligate anaerobes were uncommonly isolated due to institutional constraints.

CONCLUSION

In this environment, both ciprofloxacin and ceftazidime provide good broad-spectrum anti-microbial activity against the commonly isolated pathogens. Either agent can be used as single agent empiric therapy in patients with moderate/severe diabetic infections in our setting. Although institutional limitations precluded isolation of anaerobes in most cases, there is sufficient evidence for anti-anaerobic agents to be recommended as a part of empiric therapy.

Knowledge sharing among healthcare infection preventionists: the impact of public health professionals in a rural state

Background

Healthcare-associated infections are a major source of morbidity and mortality in the United States. Infection Preventionists (IPs) are healthcare workers tasked at overseeing the prevention and control of these infections, but they may have difficulties obtaining up-to-date information, primarily in rural states. The objective of this study was to evaluate the importance of public health involvement on the knowledge-sharing network of IPs in a rural state.

Findings

A total of 95 attendees completed our survey. The addition of public health professionals increased the density of the network, reduced the number of separate components of the network, and reduced the number of key players needed to contact nearly all of the other network members. All network metrics were higher for public health professionals than for IPs without public health involvement.

Conclusions

The addition of public health professionals involved in healthcare infection prevention activities augmented the knowledge sharing potential of the IPs in Iowa. Rural states without public health involvement in healthcare-associated infection (HAI) prevention efforts should consider the potential benefits of adding these personnel to the public health workforce to help facilitate communication of HAI-related information.

High prevalence of Panton-Valentine leukocidin among methicillin-sensitive Staphylococcus aureus colonization isolates in rural Iowa

Recent studies have shown that livestock can carry Staphylococcus aureus and transmit it to human caretakers. We conducted a pilot study to determine the prevalence and molecular epidemiology of S. aureus among rural Iowans, including individuals with livestock contact. Nasal and throat swabs were collected and plated onto selective media to isolate methicillin-susceptible and methicillin-resistant S. aureus (MRSA), followed by antibiotic resistance testing and molecular analysis of the isolates. While no MRSA was detected, overall, 23.7% (31/131) of participants were found to harbor S. aureus in their nose, throat, or both. Fifteen isolates displayed resistance to one or more tested antibiotics, and the Panton-Valentine leukocidin (PVL) genes were present at a high level (29% [9/31] of S. aureus-positive participants). Younger age and tobacco use were associated with increased risk of S. aureus carriage. Our results suggest that carriage of PVL-positive S. aureus is common among rural Iowans, even in the absence of detectable MRSA colonization.

Evaluation of risk factors for coinfection or cocolonization with vancomycin-resistant enterococcus and methicillin-resistant Staphylococcus aureus

We retrospectively evaluated 410 patients with coinfection or cocolonization due to vancomycin-resistant (VR) enterococcus (VRE) and methicillin-resistant Staphylococcus aureus (MRSA). The prevalence rate was 19.8%. Risk factors included isolation of VR Enterococcus faecalis and use of linezolid or clindamycin. Inc18-like vanA plasmids were found in 7% of VR E. faecalis isolates and none of the VR E. faecium isolates.

Effectiveness of universal screening for vancomycin-resistant enterococcus and methicillin-resistant Staphylococcus aureus on admission to a burn-trauma step-down unit

Vancomycin-resistant enterococcus (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) are significant healthcare-associated pathogens. We sought to identify factors that could be used to predict which patients carry or are infected with VRE or MRSA on admission so that we could obtain cultures selectively from high-risk patients on our burn-trauma unit. We conducted a case-control study of patients admitted to our burn-trauma unit from September 2000 to March 2005 who were colonized or infected with either VRE or MRSA (cases) and patients who were not colonized or infected with one of these organisms (controls). We used logistic regression to construct a model that we subsequently validated based on data collected prospectively from patients admitted from September 2006 to August 2007. In the case-control study, colonization or infection with MRSA or VRE on admission were independently associated with the total days of antimicrobial treatment, age, prior hospitalization, prior operations, and admitting diagnosis (admission for a burn injury was protective). In the cohort study, a prior hospitalization with a length of stay>or=7 days and operations within the past 6 months were significantly associated with colonization or infection on admission. The latter model was 59.3% sensitive. If, we used this model to identify which patients should be cultured on admission, we would have missed 24 (39.3%) of the colonized or infected patients. These patients would not have been placed in isolation (434 missed isolation days, 71.0%) and may have been the source of transmission to other patients. Our model lacked the sensitivity to identify patients colonized or infected with VRE or MRSA. We recommend that units, which care for patients who are at high risk of hospital-acquired infection and having prevalence and transmission rates of VRE or MRSA similar to those in our study, screen all patients for these organisms on admission to the unit.

Growth and geographic variation in hospitalizations with resistant infections, United States, 2000-2005

From 2000 through 2005, hospitalizations with resistant infections (methicillin-resistant Staphylococcus aureus, Clostridium difficile–associated disease, vancomycin-resistant enterococcus, Pseudomonas aeruginosa, and Candida infection) nearly doubled, from 499,702 to 947,393. Regional variations noted in the aggregate and by individual infection may help clarify modifiable risk factors driving these infections.

Vancomycin-resistant Enterococcus – A Review From a Singapore Perspective

Introduction: Vancomycin-resistant enterococcus (VRE) can cause serious infections in vulnerable, immunocompromised patients. Materials and Methods: In this article, we summarise current data on epidemiology, detection, treatment and prevention of VRE. Results: VRE was first isolated in Singapore in 1994 and until 2004 was only sporadically encountered in our public hospitals. After 2 outbreaks in 2004 and in 2005, VRE has become established in our healthcare institutions. Multiple studies have shown that VRE spreads mainly via contaminated hands, cloths and portable equipment carried by healthcare workers. Conclusions: Only a comprehensive programme (consisting of active surveillance, isolation of colonised/infected patients, strict adherence to proper infection control practices and anti-microbial stewardship) can limit the spread of these organisms. In addition to monitoring the compliance with traditional infection control measures, new strategies that merit consideration include pre-emptive isolation of patients in high-risk units and molecular techniques for the detection of VRE. Keywords: Antibiotic resistance, Infection control, Outbreaks, Surveillance

Vancomycin-resistant enterococcus in critical care areas

Colonization with VRE must be identified to prevent the spread of the disease and the progression to infection in susceptible individuals. PCR assays and culturing techniques allow nurses and other members of the health care team to identify and treat colonized and infected patients. Although currently there is no effective treatment for VRE colonization, isolation precautions are paramount to prevent increased VRE transmission. Decolonization techniques should be considered in high-risk populations. For those who have clinical evidence of VRE infection, several approved treatment regimens can be implemented. The increasing incidence of VRE with simultaneous increasing resistance patterns demands the development of new antimicrobial agents. Collaborative management of both VRE colonization and infection can reduce the sky-rocketing numbers of hospital acquired infections and mortality from VRE infections.