Journal of Hospital Infection - Articles in Press

Biocide resistance of Candida and Escherichia coli biofilms is associated with higher antioxidative capacities - Corrected Proof

C.Y. Leung, Y.C. Chan, L.P. Samaranayake, C.J. Seneviratne — 2012-05-18

Summary: Background: Most clinical guidelines for the use of biocides have been developed for planktonic micro-organisms, but in nature, most micro-organisms live as surface-adherent communities or biofilms.Aim: To evaluate the effectiveness of commonly used biocides against Escherichia coli and Candida spp. in three distinct growth phases: planktonic, adhesion and biofilm.Methods: Ultrastructural, architectural and cellular viability changes following a 5 min exposure to biocide were monitored by scanning electron microscopy and confocal laser scanning microscopy using fluorescent dyes. Comparative transcript expression of the antioxidants SOD1 and CAT1 in the planktonic and biofilm phases was evaluated using quantitative real-time polymerase chain reaction.Findings: E. coli and Candida spp. in the planktonic phase were susceptible to all the tested biocides at the recommended concentrations. However, early adhesion and late biofilm phases of both were less susceptible to the biocides, and exceeded the recommended concentrations on several occasions. A short period of biocide exposure failed to fully eradicate the adherent microbial cells, and they recovered from the biocide challenge, forming biofilm on the biocide-treated surfaces. The biofilm phase showed higher expression of SOD1 and CAT1.Conclusion: The recommended concentrations of biocides for clinical disinfection in the hospital setting may not fully eradicate the adhesion or biofilm phases of E. coli and Candida spp. Higher antioxidative capacities in microbial biofilms may be responsible for the resistance of biofilms against clinical biocides.

Microbial contamination of non-invasive ventilation devices used by adults with cystic fibrosis - Corrected Proof

2012-05-14

Summary: Background: There is currently little evidence regarding potential risks of bacterial contamination of non-invasive ventilation (NIV) devices used by cystic fibrosis (CF) patients.Aim: The aim of this study was to determine the extent of bacterial contamination of NIV devices in our regional adult CF centre.Methods: Seven NIV devices recently used by CF patients chronically infected with Pseudomonas aeruginosa or Burkholderia cepacia complex (BCC) were swabbed in seven areas, both external and internal. Two devices had undergone ethylene oxide (EtO) sterilization between patient use and swabbing, and five devices had not undergone EtO sterilization.Findings: Swabs from five devices had insignificant growth of environmental organisms and two devices had significant growth of environmental organisms. No CF pathogens were isolated from any machine.Conclusions: No evidence was found of pathogenic microbial contamination of NIV devices used by CF patients in this small study. We suggest that further studies examine for evidence of bacterial contamination of NIV devices and that this issue should be included in future CF infection control guidelines.

Plastic wound retractors as bacteriological barriers in gastrointestinal surgery: a prospective multi-institutional trial - Corrected Proof

2012-05-14

Summary: Background: Surgical site infection remains a significant problem, and peri-operative strategies to reduce wound exposure to bacteria are needed urgently. Plastic ring wound retractors, used to gain access to the abdominal cavity, may shield the incision site from bacteria.Aim: To evaluate exposure of the surgical incision site to bacteria using a plastic ring wound retractor in gastrointestinal surgery.Methods: Prospective, observational, multi-centre study. Patients undergoing clean-contaminated gastrointestinal surgery with standard antibiotic prophylaxis were included (N = 250 patients, 500 samples). A plastic wound retractor was used to facilitate access to the abdominal cavity. Samples were taken for bacterial culture from the inside (luminal) and outside (wound) surfaces of the retractor at the end of the operation.Findings: Bacteria were found on 56% (140/250) of samples from the inside surface of the retractor compared with 34% (85/250) of samples from the outside surface of the retractor (P < 0.0001). There was no significant difference in skin-derived organisms from the inside [34/245 (14%)] and outside [27/250 (11%)] surfaces of the retractor (P = 0.108). However, enteric organisms were cultured twice as often from the inside surface of the retractor compared with the outside surface of the retractor (49% vs 26%, respectively; P < 0.0001).Conclusion: Plastic wound retractors reduce wound exposure to enteric bacteria in gastrointestinal surgery.

Surgical site infection, ultraclean ventilated operating theatres and prosthetic joint surgery: where now? - Corrected Proof

H. Humphreys — 2012-05-14

Recent years have seen a number of reviews and guidelines on the prevention of surgical site infection (SSI) which focus on pre-, peri- and postoperative factors. However, these guidelines make very little reference to the physical circumstances or conditions under which the surgery takes place. Tradition and practice has been for most general surgical procedures to take place in a plenum ventilated operating theatre with about 20 air changes per hour and for much of prosthetic joint surgery to take place under laminar flow conditions with ultraclean ventilation.

Influence of laminar airflow on prosthetic joint infections: a systematic review - Corrected Proof

P. Gastmeier, A.-C. Breier, C. Brandt — 2012-05-11

Summary: Background: Many hospitals use ultraclean ventilation (UVC), also known as laminar airflow systems (LAF), in their operating rooms to decrease rates of surgical site infections (SSIs). However, the evidence for these systems is limited and the additional expenses for LAF are substantial.Aim: To determine the effectiveness of LAF to decrease SSI rates following hip and knee prosthesis.Methods: Systematic review of cohort studies investigating the influence of LAF on SSIs following hip and knee prosthesis published during the last 10 years.Findings: Four cohort studies using the endpoint severe SSI following knee prosthesis and four studies following hip prosthesis were included. No individual study showed a significant benefit for LAF following knee prosthesis but one small study showed a significant benefit following hip prosthesis. However, one individual study showed significantly higher severe SSI rates following knee prosthesis and three studies significantly higher SSI rates following hip prosthesis under LAF conditions. The summary odds ratio was 1.36 (95% confidence interval: 1.06–1.74) for knee prosthesis and 1.71 (1.21–2.41) for hip prosthesis.Conclusions: It would be a waste of resources to establish new operating rooms with LAF, and questionable as to whether LAF systems in existing operating rooms should be replaced by conventional ventilation systems.

The Mike Emmerson Young Investigator's Award - Corrected Proof

2012-05-07

Applications are invited for project grants to support work on the subject of ‘healthcare-associated infection prevention and control’, to be carried out in the UK or Eire only.

Corrigendum to “Modelling the transmission dynamics of meticillin-resistant Staphylococcus aureus in Beijing Tongren hospital” [Journal of Hospital Infection 2011;79:302–308] - Corrected Proof

J. Wang, L. Wang, P. Magal, Y. Wang, J. Zhuo, X. Lu, S. Ruan — 2012-05-07

In the process of revising the manuscript, an error was made in combining figures. The correct Figure 6b should be as follows: Accordingly, on page 336, left panel, line 10 above Figure 5, “however, the effect of hand hygiene among volunteers is more dramatic” should read as “however, the effect of hand hygiene among healthcare workers is more dramatic”.

Differences in the compliance with hospital infection control practices during the 2009 influenza H1N1 pandemic in three countries - Corrected Proof

2012-05-07

Summary: Background: In December 2009, the World Health Organization (WHO) issued updated guidelines on the prevention of H1N1 influenza virus in healthcare settings. In 2010, the WHO pandemic influenza alert level was still at phase 6.Aim: To study the practice of infection control measures during the 2009 influenza H1N1 pandemic among healthcare workers (HCWs) in three countries.Methods: A standardized, self-administered anonymous questionnaire survey was conducted in 2010 among doctors, nurses and allied HCWs in 120 hospital-based clinical departments in Hong Kong, Singapore and the UK. Questions were asked on demographics; previous experience and perceived severity of influenza; infection control practices; uptake of seasonal influenza vaccination and H1N1 vaccination. Multiple logistic regression was used to test the independent association with different factors.Findings: A total of 2100 HCWs in the three countries participated. They reported high compliance (>80%) with infection control procedures regarded as standard for droplet-transmitted infections including wearing and changing gloves, and washing hands before and after patient contact. However, the reported use of masks with indirect or direct patient contact (surgical or N95 as required by their hospital) varied considerably (96.4% and 70.4% for Hong Kong; 82.3% and 87.7% for Singapore; 25.3% and 62.0% for the UK). Reported compliance was associated with job title, number of patient contacts and perceived severity of pandemics. There was no association between the uptake for seasonal or 2009 H1N1 vaccines and compliance.Conclusions: Compliance with infection control measures for pandemic influenza appears to vary widely depending on the setting.

Rapid detection of intestinal carriage of Klebsiella pneumoniae producing KPC carbapenemase during an outbreak - Corrected Proof

2012-05-07

Summary: Two different approaches are described for rapid detection of intestinal carriage of Klebsiella pneumoniae producing KPC-type carbapenemase (KPC-KP), based on PCR amplification of DNA extracts from rectal swabs (K-PCR), and on direct plating of rectal swabs on to MacConkey agar with a meropenem disc and a meropenem plus 3-aminophenylboronic acid disc (direct KPC screening test, DKST). K-PCR and DKST were tested with a total of 101 samples from 65 patients, during an outbreak. Although less sensitive, DKST could detect high-level carriage, which appears to be common among infected and colonised patients, while being very cheap and easy to perform, and requiring only basic facilities.

Neonatal influenza A/H1N1/2009 outbreak in a UK district general hospital - Corrected Proof

M. Milupi, M. Madeo, N. Brooke, S.J. Ahmad — 2012-05-07

Summary: Increasing numbers of cases of neonatal influenza A/H1N1/2009 are being reported in the literature but there are no specific guidelines on outbreak management. We report an outbreak of influenza A/H1N1/2009 in a newborn intensive care unit in a large district general hospital. The index case probably acquired the infection from the mother. Subsequently two other babies were infected, possibly due to the use of continuous positive airway pressure ventilation. The outbreak was brought under control with enhanced surveillance and screening of contacts, isolation of confirmed cases and the use of oseltamivir.

Hospital infestations by the moth fly, Clogmia albipunctata (Diptera: Psychodinae), in Germany - Corrected Proof

M. Faulde, M. Spiesberger — 2012-05-07

Summary: The moth fly Clogmia albipunctata, formerly a Mediterranean species, is now present in Germany, at latitudes exceeding 53°N. Its synanthropic behaviour allows frequent, year-round infestations in hospital buildings. Hospital infestations have been most common in shower and rest rooms in patient wards, followed by cellar storage rooms, and then rest and shower rooms in hospital kitchens. Preferred breeding sites included hair-clogged sinks in patient shower cubicles, infrequently used toilets and urinals as well as water sources stemming from neglected leaking pipes, suggesting that enhanced hospital water and pest management are necessary for control.

Procalcitonin in early onset ventilator-associated pneumonia - Corrected Proof

U. Zielińska-Borkowska, T. Skirecki, M. Złotorowicz, B. Czarnocka — 2012-05-03

Summary: Background: Ventilator-associated pneumonia (VAP) is a significant problem in intensive care and there exists great demand for a suitable biomarker. Procalcitonin (PCT) has been proposed as a candidate marker.Aim: To assess the clinical usefulness of monitoring PCT concentrations in non-surgical patients with early onset VAP.Methods: Thirty-four patients were enrolled with early onset VAP defined as VAP diagnosed between 48 h and 6 days of the onset of mechanical ventilation. Serum PCT was measured on days 1, 2, 3, 5, 6 and 7.Findings: The mortality rate was 21%. Non-survivors had significantly elevated PCT levels on days 3 and 7. For non-survival, the areas under the receiver operator curve (AUC) for PCT were 0.762 [95% confidence interval (CI): 0.6–0.923] on day 3 and 0.754 (95% CI: 0.586–0.922) on day 7. Among septic patients, PCT was significantly higher on days 1, 2, 3, 5, and 7, with the highest AUC on day 1 (0.783; 95% CI: 0.626–0.94): a cut-off of 1 ng/mL on day 1 had a positive predictive value of 0.813 for the development of septic shock.Conclusion: No association was found between PCT concentration and the adequacy of antibiotic therapy or the aetiology of VAP. In logistic regression analysis, PCT was not significantly correlated with poor outcome. Although PCT levels were higher in non-survivors and those who developed septic shock, PCT is not a strong predictor of these outcomes.

Economic burden of ventilator-associated pneumonia in a developing country - Corrected Proof

E. Alp, G. Kalin, R. Coskun, M. Sungur, M. Guven, M. Doganay — 2012-05-03

Summary: Ventilator-associated pneumonia (VAP) developed in 96 (60%) of 159 patients with 37.2 cases per 1000 ventilation-days in a medical intensive care unit (MICU). Median time for VAP development was 5.5 days (range: 2–25). The most significant risk factors for VAP were stay in hospital before MICU and length of stay in MICU. The mean length of stay in MICU for VAP patients was 23.8 ± 19.8 days, which was four-fold higher than for non-VAP patients. The daily cost for VAP patients was half that for non-VAP patients. The total costs for VAP patients were about three-fold higher than for non-VAP patients.

Misidentification slanders Pantoea agglomerans as a serial killer - Corrected Proof

F. Rezzonico, T.H.M. Smits, B. Duffy — 2012-05-03

Pantoea agglomerans is an ecologically versatile species that has important beneficial applications in agriculture as a biological alternative to antibiotic use for orchard protection against phytopathogenic bacteria. Disease-suppressive, biocontrol isolates are among the most effective tools available to manage fire blight, an invasive threat to global apple and pear production. P. agglomerans-based products are registered for biocontrol in the USA, Canada and New Zealand, but clinical reports have been a regulatory obstacle in Europe. Thus, the recent report of a fatal bacteraemia outbreak attributed to P. agglomerans is alarming and would have significant socio-economic impact, if the conclusion of clinical pathogenicity was correct.

Guidelines for preventing catheter infection: assessment of knowledge and practice among paediatric and neonatal intensive care healthcare workers - Corrected Proof

2012-04-19

Summary: We analysed knowledge of and adherence to guidelines for the prevention of catheter-related infection (CRI) among Spanish healthcare workers (HCWs) from paediatric and neonatal intensive care units by distributing 357 questionnaires to 31 Spanish hospitals. The overall mean scores for individual knowledge and daily practice were 5.61 and 5.78, respectively. Our results reveal room for improvement in Spanish HCWs' knowledge of prevention of CRI. Continuing education programmes and implementation of care bundles must be introduced to improve prevention and management of CRI.

Klebsiella pneumoniae susceptibility to biocides and its association with cepA, qacΔE and qacE efflux pump genes and antibiotic resistance - Corrected Proof

A. Abuzaid, A. Hamouda, S.G.B. Amyes — 2012-04-12

Summary: Background: Although antiseptics are some of the most widely used antibacterials in hospitals, there is very little information on reduced susceptibility to these biocides and its relationship with resistance to antibiotics.Aim: To determine the relationship between reduced susceptibility to biocides and the carriage of antiseptic resistance genes, cepA, qacΔE and qacE, as well as identifying the role of efflux pumps in conferring reduced susceptibility.Methods: Susceptibility was assessed for five biocides: chlorhexidine, benzalkonium chloride, Trigene, MediHex-4, Mediscrub; and for 11 antibiotics against 64 isolates of Klebsiella pneumoniae. Susceptibility to all compounds was tested by the agar double dilution method (DDM) and the effect of efflux pumps on biocides determined by repeating the susceptibility studies in the presence of the efflux pump inhibitor carbonyl cyanide m-chlorophenyl hydrazone (CCCP). The presence of the cepA, qacΔE and qacE genes was identified by polymerase chain reaction.Findings: The bacteria were not widely antibiotic resistant though a few showed reduced susceptibility to cefoxitin, chloramphenicol and rifampicin and later-generation cephalosporins but not to carbapenems. Biocide susceptibility, tested by DDM, showed that 50, 49 and 53 strains had reduced susceptibility to chlorhexidine, Trigene and benzalkonium chloride, respectively. The antiseptic resistance genes cepA, qacΔE and qacE were found in 56, 34 and one isolates respectively and their effects as efflux pumps were determined by CCCP (10 mg/L), which decreased the minimum inhibitory concentrations (MICs) of chlorhexidine and Medihex-4 by 2–128-fold but had no impact on the MICs of benzalkonium chloride, Trigene and Mediscrub.Conclusion: There was a close link between carriage of efflux pump genes, cepA, qacΔE and qacE genes and reduced biocide susceptibility, but not antibiotic resistance, in K. pneumoniae clinical isolates.

Bloodstream infections caused by Stenotrophomonas maltophilia: a seven-year review - Corrected Proof

M. Garazi, C. Singer, J. Tai, C.C. Ginocchio — 2012-04-11

Summary: Background: Stenotrophomonas maltophilia is a significant nosocomial pathogen, responsible for an increasing number of infections, particularly in immunocompromised patients.Aim: This study describes the clinical and microbiological characteristics of patients with Stenotrophomonas maltophilia bacteraemia.Methods: We reviewed the charts of 102 patients with Stenotrophomonas maltophilia bacteraemia over a seven-year period from 2001 to 2007 in two tertiary care centres in New York, USA.Findings: There were 79 episodes (77.5%) related to nosocomial acquisition, 21 (20.6%) were healthcare-associated and two episodes (2%) were community-acquired. The most common source of bacteraemia was an infected central catheter in 44 patients (43.1%); 17 (16.6%) were related to neutropenic sepsis; nine (8.8%) were from an abdominal source; six (5.9%) were from a respiratory source, and the source of the bacteraemia was unclear in 26 cases (25.5%). The majority (94.1%) of the patients had central venous access devices. Intensive care unit stay, intubation, septic shock, neutropenia at the time of bacteraemia or carbapenem antibiotic use within 30 days of the episode were associated with mortality according to univariate analysis. By multivariate analysis, hypotensive shock and carbapenem use within 30 days of the episode were factors significantly correlated with mortality. The 102 isolates were mostly susceptible in vitro to trimethoprim–sulfamethoxazole (97.1%), levofloxacin (92.9%), ceftazidime (53.0%) and ticarcillin–clavulanic acid (49.2%).Conclusion: Our data describe the characteristics of patients with Stenotrophomonas maltophilia bacteraemia and emphasize the importance of careful evaluation of vascular access devices in those patients.

Reply to: Kampf G, Ostermeyer C. World Health Organization-recommended hand-rub formulations do not meet European efficacy requirements for surgical hand disinfection in five minutes (J Hosp Infect 2011;78:123–127) - Corrected Proof

2012-03-27

We read the article by Kampf and Ostermeyer with interest. We acknowledge that the reported efficacy test results according to European Norm (EN) 12791 bring additional evidence to demonstrate that the World Health Organization (WHO)-recommended alcohol-based hand-rub formulations are inferior to the reference agent (n-propanol 60%) when evaluated in the laboratory for surgical hand preparation. Similar results were indeed disclosed by WHO within the Guidelines on hand hygiene in health care. Importantly, however, at the time of the Guidelines’ publication (2009), the task force of international experts agreed that the two WHO formulations could be used for surgical hand preparation, considering that they have critical properties for sustained clinical use: excellent tolerability, good acceptance by healthcare workers, demonstrated clinical impact and low cost. The task force recommended a minimum of three applications (more applications being better), for a period of 3–5 min when the WHO formulations are used for surgical hand preparation; for surgical procedures lasting more than two hours, a second hand rub of ∼1 min was also recommended. The data presented by Kampf and Ostermeyer were discussed by the same experts in a meeting convened by WHO in July 2011. The task force advocated that the WHO recommendations remain unchanged, until WHO is able to complete further study of the issue leading to suitable modifications of the WHO formulations.

Final comment on letter by Allegranzi et al. - Corrected Proof

G. Kampf, C. Ostermeyer — 2011-12-12

We thank our respected colleagues for their interest and comments on our work and are grateful to learn that both World Health Organization (WHO)-recommended formulations will probably be changed in order to improve their efficacy, which has also been indicated by Suchomel et al.