Contamination of renal patients' hospital chart covers with vancomycin-- resistant enterococci: Handle with care

Transmission routes of antibiotic resistant bacteria: a systematic review

Background

Quantification of acquisition routes of antibiotic resistant bacteria (ARB) is pivotal for understanding transmission dynamics and designing cost-effective interventions. Different methods have been used to quantify the importance of transmission routes, such as relative risks, odds ratios (OR), genomic comparisons and basic reproduction numbers. We systematically reviewed reported estimates on acquisition routes’ contributions of ARB in humans, animals, water and the environment and assessed the methods used to quantify the importance of transmission routes.

Methods

PubMed and EMBASE were searched, resulting in 6054 articles published up until January 1st, 2019. Full text screening was performed on 525 articles and 277 are included.

Results

We extracted 718 estimates with S. aureus (n = 273), E. coli (n = 157) and Enterobacteriaceae (n = 99) being studied most frequently. Most estimates were derived from statistical methods (n = 560), mainly expressed as risks (n = 246) and ORs (n = 239), followed by genetic comparisons (n = 85), modelling (n = 62) and dosage of ARB ingested (n = 17). Transmission routes analysed most frequently were occupational exposure (n = 157), travelling (n = 110) and contacts with carriers (n = 83). Studies were mostly performed in the United States (n = 142), the Netherlands (n = 87) and Germany (n = 60). Comparison of methods was not possible as studies using different methods to estimate the same route were lacking. Due to study heterogeneity not all estimates by the same method could be pooled.

Conclusion

Despite an abundance of published data the relative importance of transmission routes of ARB has not been accurately quantified. Links between exposure and acquisition are often present, but the frequency of exposure is missing, which disables estimation of transmission routes’ importance. To create effective policies reducing ARB, estimates of transmission should be weighed by the frequency of exposure occurrence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07360-z.

Outbreak report: a nosocomial outbreak of vancomycin resistant enterococci in a solid organ transplant unit

Background

Vancomycin resistant enterococci (VRE) are an emerging problem in health care settings. The purpose of the investigation was to assess the extent of the outbreak including environmental contamination and to limit further transmission.

Methods

We used retrospective patient and laboratory data including pulse field gel electrophoresis (PFGE) typing and virulence and resistance gene analysis. For comparison of medians the Mann-Whitney and for comparison of proportions the Fisher exact tests were used.

Results

PFGE typing of VRE strains of an outbreak of 15 VRE cases in a solid transplant unit revealed that nine of the cases belonged to one identical pattern (A), which was only found twice in the environment. Eleven further positive environmental samples showed a different, but identical PFGE pattern E. Only one patient was infected with this environmental strain.

Two of nine (22.2%) PFGE A, but nine of eleven (81.2%) PFGE E samples were positive for gelatinase E (p = 0.01), which is described as enhancing biofilm production, suggesting a survival benefit for this strain on inanimate surfaces.

Conclusion

Routine disinfection was not able to stop the cluster, but after repeated enforcement of the infection prevention and control (IPC) bundle such as training, strict adherence to hand hygiene and surface disinfection no further cases were observed. We conclude that certain VRE strains predominate in the environment whereas others predominate in humans. Enforcement of the IPC bundle is essential for controlling VRE outbreaks and reducing further transmission.

Contamination of medical charts: an important source of potential infection in hospitals

OBJECTIVE

This prospective study aims to identify and compare the incidence of bacterial contamination of hospital charts and the distribution of species responsible for chart contamination in different units of a tertiary hospital.

METHODS

All beds in medical, surgical, pediatric, and obstetric-gynecologic general wards (556) and those in corresponding special units (125) including medical, surgical, pediatric intensive care units (ICUs), the obstetric tocolytic unit and delivery room were surveyed for possible chart contamination. The outer surfaces of included charts were sampled by one experienced investigator with sterile cotton swabs rinsed with normal saline.

RESULTS

For general wards and special units, the overall sampling rates were 81.8% (455/556) and 85.6% (107/125) (p = 0.316); the incidence of chart contamination was 63.5% and 83.2%, respectively (p<0.001). Except for obstetric-gynecologic charts, the incidence was significantly higher in each and in all ICUs than in corresponding wards. Coagulase-negative staphylococci was the most common contaminant in general wards (40.0%) and special units (34.6%) (p>0.05). Special units had a significantly higher incidence of bacterial contamination due to Staphylococcus aureus (17.8%), Methicillin-resistant Staphylococcus aureus (9.3%), Streptococcus viridans (9.4%), Escherichia coli (11.2%), Klebsiella pneumoniae (7.5%), and Acinetobacter baumannii (7.5%). Logistic regression analysis revealed the incidence of chart contamination was 2- to 4-fold higher in special units than in general wards [odds ratios: 1.97-4.00].

CONCLUSIONS

Noting that most hospital charts are contaminated, our study confirms that a hospital chart is not only a medical record but also an important source of potential infection. The plastic cover of the medical chart can harbor potential pathogens, thus acting as a vector of bacteria. Additionally, chart contamination is more common in ICUs. These findings highlight the importance of effective hand-washing before and after handling medical charts. However, managers and clinical staff should pay more attention to the issue and may consider some interventions.