Journal of Hospital Infection

Editorial Board

2012-05-01

Clinical and economic burden of Clostridium difficile infection in Europe: a systematic review of healthcare-facility-acquired infection

P.N. Wiegand, D. Nathwani, M.H. Wilcox, J. Stephens, A. Shelbaya, S. Haider — 2012-04-12

Summary: PubMed, EMBASE and conference abstracts were reviewed systematically to determine the clinical and economic burden associated with Clostridium difficile infection (CDI) acquired and treated in European healthcare facilities. Inclusion criteria were: published in the English language between 2000 and 2010, and study population of at least 20 patients with documented CDI acquired/treated in European healthcare facilities. Data collection was completed by three unblinded reviewers using the Cochrane Handbook and PRISMA statement. The primary outcomes were mortality, recurrence, length of hospital stay (LOS) and cost related to CDI. In total, 1138 primary articles and conference abstracts were identified, and this was narrowed to 39 and 30 studies, respectively. Data were available from 14 countries, with 47% of studies from UK institutions. CDI mortality at 30 days ranged from 2% (France) to 42% (UK). Mortality rates more than doubled from 1999 to 2004, and continued to rise until 2007 when reductions were noted in the UK. Recurrent CDI varied from 1% (France) to 36% (Ireland); however, recurrence definitions varied between studies. Median LOS ranged from eight days (Belgium) to 27 days (UK). The incremental cost of CDI was £4577 in Ireland and £8843 in Germany, after standardization to 2010 prices. Country-specific estimates, weighted by sample size, ranged from 2.8% to 29.8% for 30-day mortality and from 16 to 37 days for LOS. CDI burden in Europe was most commonly described using 30-day mortality, recurrence, LOS and cost data. The continued spread of CDI and resultant healthcare burden underscores the need for judicious use of antibiotics.

Reduced susceptibility to chlorhexidine among extremely-drug-resistant strains of Klebsiella pneumoniae

L. Naparstek, Y. Carmeli, I. Chmelnitsky, E. Banin, S. Navon-Venezia — 2012-04-05

Summary: Background: Over the last decade, extremely-drug-resistant (XDR) strains of Klebsiella pneumoniae have emerged worldwide, mainly as a result of patient-to-patient spread. The predominant clone, sequence type 258 (ST258), is associated with high morbidity and mortality, and is a worldwide threat to public health. It was hypothesized that reduced susceptibility to chlorhexidine, the most widely used hospital disinfectant, may contribute to the endemic nature of this strain.Aim: To characterize and compare the susceptibility of the epidemic K. pneumoniae clone ST258 and non-epidemic K. pneumoniae clones to chlorhexidine.Methods: The minimum inhibitory concentration (MIC) of chlorhexidine was determined in 126 XDR K. pneumoniae clinical isolates using agar dilution. Expression of three different efflux pumps – cepA, acrA and kdeA – was investigated in the absence and presence of chlorhexidine using quantitative real-time polymerase chain reaction. Heteroresistance to chlorhexidine was identified using population analysis.Findings: The MIC of chlorhexidine was higher for K. pneumoniae ST258 (N = 70) than other K. pneumoniae sequence types (N = 56); 99% of ST258 isolates had MICs >32 μg/mL, compared with 52% of other K. pneumoniae sequence types (P < 0.0001). Reduced susceptibility to chlorhexidine appeared to be independent of the expression of cepA, acrA and kdeA efflux pumps. Chlorhexidine-resistant subpopulations were observed independent of the bacterial sequence type or the MIC.Conclusions: Reduced susceptibility to chlorhexidine may contribute to the success of XDR K. pneumoniae as a nosocomial pathogen, and may provide a selective advantage to the international epidemic strain K. pneumoniae ST258. The heterogeneous nature of chlorhexidine-resistant subpopulations suggests that this phenomenon might not be rendered genetically.

Evaluation of chromogenic meticillin-resistant Staphylococcus aureus media: sensitivity versus turnaround time

K. Morris, C. Wilson, M.H. Wilcox — 2012-04-05

Summary: Background: Chromogenic media offer the potential for improved detection of meticillin-resistant Staphylococcus aureus (MRSA). Incubation times in a clinical setting vary, generally between 16 and 48 h.Aim: To investigate the effects of incubation time on the performance of commercial chromogenic MRSA media.Methods: We initially compared the early recovery of MRSA isolates from routine screening swabs following 16–23 h to that after 22–24 h of incubation using ChromID MRSA (bioMérieux). We also compared ChromID MRSA, ChromID MRSA V2 (bioMérieux), Brilliance MRSA 2 Agar (Oxoid) and Colorex MRSA (E&O Laboratories Ltd) as selective media for 6035 MRSA screening swabs.Findings: Only 303 of 623 (48.6%) MRSA isolates detected by this medium after 48 h were recovered after 16–23 h compared with 726 of 1018 (71.3%) isolates after 22–24 h. Following implementation of the 22–24 h incubation period, 50 (4.4%) isolates exhibiting a positive chromogenic reaction gave conflicting coagulase latex and DNase results. In 88% of these cases, DNase gave the correct result of non-MRSA. ChromID MRSA demonstrated the highest sensitivity overall at 93.2%, followed by Colorex MRSA Agar (87.1%), ChromID V2 (83.7%) and Brilliance Agar (78.2%). All media exhibited specificities of >99.7%.Conclusion: Early detection of MRSA using ChromID MRSA is best achieved after incubation for 22–24 h. Latex agglutination coagulase tests alone should not be relied upon for identification of MRSA isolates from this medium. Although ChromID MRSA was deemed the superior medium in terms of MRSA recovery, the disadvantages of increased turnaround time (48 vs 24 h) must be considered.

Lessons from a large norovirus outbreak: impact of viral load, patient age and ward design on duration of symptoms and shedding and likelihood of transmission

D.G. Partridge, C.M. Evans, M. Raza, G. Kudesia, H.K. Parsons — 2012-03-26

Summary: Background: Hospital norovirus outbreaks cause significant financial and operational disruption which should be minimised by optimal handling of affected areas and use of isolation facilities.Aim: To identify factors associated with increased duration of symptoms and viral excretion and increased probability of transmission.Methods: Retrospective observational study of a large norovirus outbreak at a UK teaching hospital in the winter of 2009–2010 where patients were diagnosed using a real-time polymerase chain reaction (PCR) assay.Findings: Symptom duration was significantly associated with patient age (Spearman rank correlation coefficient: 0.197; P = 0.002) but not with PCR cycle threshold (CT) value. Duration of viral excretion was found to be longer in patients with higher viral loads. Transmission within a ward bay was not significantly associated either with age or with CT value but was more likely to occur in some ward blocks than others, which may relate to differences in ward design. Transfer of patients into isolation rooms or cohorted area within two days of symptom onset did not significantly influence probability of onward transmission (52% vs 47%; P = 0.67).Conclusions: The presented data suggest that CT value may guide timing of repeat sample collection if ongoing gastrointestinal symptoms may relate to other pathologies, and that patients developing symptoms of norovirus may remain in their current bay rather than being moved into isolation facilities. The bay or ward should be closed to new admissions but it should be anticipated that duration of symptoms and therefore closure will be longer when the outbreak involves elderly patients.

Dermal and pulmonary absorption of ethanol from alcohol-based hand rub

D. Ahmed-Lecheheb, L. Cunat, P. Hartemann, A. Hautemanière — 2012-03-26

Summary: Background: Ethanol intoxication of healthcare workers (HCWs) using alcohol-based hand rubs (ABHRs) in the workplace is a potentially serious issue. This study quantified the level of ethanol absorption among HCWs after hygienic hand disinfection.Methods: Eighty-six HCWs from Nancy University Hospital were tested before and after a 4-h shift. Participants used ABHR containing 70% ethanol. Levels of ethanol, acetaldehyde and acetate in blood and urine were determined using gas chromatography. A breathalyzer was used to measure the level of ethanol in expired air.Results: Ethanol [mean concentration 0.076 (standard deviation 0.05) mg/L] was detected in the expired air of 28 HCWs 1–2 min post exposure. Ethanol, acetaldehyde and acetate were undetectable in blood after a 4-h shift, and urine tests were negative in all participants.Conclusion: Ethanol exposure from ABHR, particularly inhalation of vapours, resulted in positive breathalyzer readings 1–2 min after exposure. Dermal absorption of ethanol was not detected. Pulmonary absorption was detected but was below toxic levels.

Influenza A/H1N1/2009 outbreak in a neonatal intensive care unit

2012-04-05

Summary: Background: Outbreaks of influenza A/H1N1/2009 in neonatal intensive care units (NICUs) have been reported only rarely. Annual vaccination of all healthcare workers (HCWs) against seasonal influenza is recommended but compliance is low and exposure to infected staff as the source of nosocomial outbreaks has been described.Aim: To report an outbreak of influenza A/H1N1/2009 in a tertiary level NICU that resulted in considerable morbidity.Methods: When the first influenza case was identified, a prospective study was conducted and control measures were implemented to reduce the spread of infection throughout the NICU. Neonates who developed influenza were treated with oseltamivir, and exposed neonates were given prophylaxis with oseltamivir.Findings: Two infected infants who were immature by gestational age and birth weight developed pneumonitis requiring respiratory support, and a third full-term neonate had a mild uncomplicated illness. No significant adverse effects were noted during antiviral treatment or prophylaxis. The investigation identified infected HCWs as the likely source of the outbreak. There was a very low influenza vaccination rate of 15% among nursing staff.Conclusion: Nosocomial influenza can cause considerable morbidity, especially in high risk neonates, and is readily transmissible in the NICU setting by unvaccinated staff members who contract influenza. To prevent outbreaks, in addition to infection control measures, the implementation of HCW vaccination is very important. Oseltamivir treatment was well-tolerated even among premature infants and appeared to be effective, because neonates with influenza had complete recovery and only one of those who received prophylaxis developed the infection.

Electrolysis-assisted sonication for removal of proteinaceous contamination from surgical grade stainless steel

S. Kumar, W.T. Lee, E.J. Szili — 2012-03-23

Summary: Background: Current methods used for the detection of residual proteinaceous contamination vary in sensitivity and specificity. This is of concern because it increases the risk for transmission of neurodegenerative diseases such as spongiform encephalopathies.Aim: To determine the effectiveness of electrolysis-assisted sonication (EAS) for removing residual proteinaceous contamination from surgical grade stainless steel.Methods: EAS was used to clean surgical grade 316L stainless steel that had been contaminated with the protein bovine serum albumin. Using nitrogen, an abundant element in proteins, as a marker for the presence of protein, X-ray photoelectron spectroscopy (XPS) was used to quantify the amount of protein remaining on the substrate surface. Cathodic, anodic and dual polarization modes of EAS were investigated using 0.1% NaCl solution (w/v, in deionized water) as the electrolyte medium and 13 V as the polarization voltage.Finding: EAS under dual polarization was found to be the most effective method for removing the residual protein layer down to an estimated XPS detection limit of 10 ng/cm2. Surface roughness and hardness of the stainless steel remained unchanged following EAS treatment, indicating that the procedure does not compromise the material’s properties.Conclusion: This relatively inexpensive and quick method of cleaning medical devices using an easily accessible salt-based electrolyte solution may offer a cost-effective strategy for cleaning medical and dental devices made of stainless steel in the future.

Microbial air monitoring in operating theatres: experience at the University Hospital of Parma

2012-04-05

Summary: Background: Microbial air monitoring in operating theatres has been a subject of interest and debate. No generally accepted sampling methods and threshold values are available.Aim: To assess microbial air contamination in empty and working conventionally ventilated operating theatres over a three-year period at the University Hospital of Parma, Italy.Methods: Air sampling was performed in 29 operating theatres. Both active and passive sampling methods were used to assess bacterial and fungal contamination.Findings: In empty theatres, median bacterial values of 12 colony-forming units (cfu)/m3 [interquartile range (IQR) 4–32] and 1 index of microbial air contamination (IMA) (IQR 0–3) were recorded. In working theatres, these values increased significantly (P < 0.001) to 80 cfu/m3 (IQR 42–176) and 7 IMA (IQR 4–13). Maximum recorded values were 166 cfu/m3 and 8 IMA for empty theatres, and 798 cfu/m3 and 42 IMA for working theatres. Combining active and passive samplings, fungi were isolated in 39.13% of samples collected in empty theatres and 56.95% of samples collected in working theatres. Over the three-year study period, bacterial contamination decreased in both empty and working theatres, and the percentage of samples devoid of fungi increased. In working theatres, a significant correlation was found between the bacterial contamination values assessed using passive and active sampling methods (P < 0.001).Conclusion: Microbiological monitoring is a useful tool for assessment of the contamination of operating theatres in order to improve air quality.

Pre-operative skin preparation practices: results of the 2007 French national assessment

2012-02-06

Summary: Background: Pre-operative skin preparation, aimed at reducing the endogenous microbial flora, is one of the main preventive measures employed to decrease the likelihood of surgical site infection. National recommendations on pre-operative management of infection risks were issued in France in 2004.Aim: To assess compliance with the French national guidelines for pre-operative skin preparation in 2007.Methods: A prospective audit was undertaken in French hospitals through interviews with patients and staff, and observation of professional practice. Compliance with five major criteria selected from the guidelines was studied: patient information, pre-operative showering, pre-operative hair removal, surgical site disinfection and documentation of these procedures.Findings: Data for 41,188 patients from all specialties at 609 facilities were analysed. Patients were issued with information about pre-operative showering in 88.2% of cases [95% confidence interval (CI) 87.9–88.5]. The recommended procedure for pre-operative showering, including hairwashing, with an antiseptic skin wash solution was followed by 70.3% of patients (95% CI 69.9–70.8); this percentage was higher when patients had received appropriate information (P < 0.001). Compliance with hair removal procedures was observed in 91.5% of cases (95% CI 91.2–91.8), and compliance with surgical site disinfection recommendations was observed in 25,529 cases (62.0%, 95% CI 61.5–62.5). The following documentary evidence was found: information given to patient, 35.6% of cases; pre-operative surgical hygiene, 82.3% of cases; and pre-operative site disinfection, 71.7% of cases.Conclusion: The essential content of the French guidelines seems to be understood, but reminders need to be issued. Some recommendations may need to be adapted for certain specialties.

Dirty utility room design and aerosolization of organisms

J.C. Macve, M.J. Weinbren — 2012-04-09

The recent study by Best et al. demonstrated that flushing toilets with the lid open can result in aerosolization of Clostridium difficile, with detection of the organism from the air at 25 cm above the bowl.

Research Grants

2012-04-05

Applications are invited for project grants to support work on the subject of ‘healthcare infection control’, to be carried out in the UK or Eire only. Two types of funding are available:

Best Review 2011

2012-04-09

For some years, it has been the practice of the Journal of Hospital Infection to consider, at the end of each year, the review articles published over the previous 12 months. The Journal of Hospital Infection is pleased to announce that for 2011, the best review was judged to be ‘Routine hand hygiene audit by direct observation: has nemesis arrived?’ by D.J. Gould, N.S. Drey and S. Creedon. The authors of this review will therefore receive a donation of £100 from the Healthcare Infection Society.