Interventions to improve patient hand hygiene: a systematic review.

Nosocomial pathogens may be acquired by patients via their own unclean hands, but there has been relatively little emphasis on patient hand hygiene as a tool for preventing healthcare-associated infections (HCAIs). The aim of this systematic review was to determine the efficacy of patient hand hygiene interventions in reducing HCAIs and improving patient hand hygiene rates compared to usual care. Electronic databases and grey literature were searched to August 2014. Experimental and quasi-experimental studies were included if they evaluated a patient hand hygiene intervention conducted in an acute or chronic healthcare facility and included HCAI incidence and/or patient hand hygiene rates as an outcome. All steps were performed independently by two investigators. Ten studies were included, most of which were uncontrolled before-after studies (N=8). The majority of interventions (N=7) were multi-modal, with components similar to healthcare worker hand hygiene programmes, including education, reminders, audit and feedback, and provision of hand hygiene products. Six studies reported HCAI outcomes and four studies assessed patient hand hygiene rates; all demonstrated improvements but were at moderate to high risk of bias. In conclusion, interventions to improve patient hand hygiene may reduce the incidence of HCAIs and improve hand hygiene rates, but the quality of evidence is low. Future studies should use stronger designs and be more selective in their choice of outcomes.

Hand hygiene monitoring technology: a systematic review of efficacy.

Electronic and video monitoring systems (EMS/VMS) may improve hand hygiene by providing feedback, real-time reminders or via the Hawthorne effect. The aim of this systematic review was to assess the efficacy of EMS/VMS in improving hand hygiene or reducing the incidence of healthcare-associated infection (HCAI). Experimental and quasi-experimental studies were included if they measured any hand hygiene outcome and/or HCAI incidence. Of the studies included, seven used system-defined compliance (SDC) (N = 6) or hand hygiene event rate (N = 1) as their outcome. SDC differed for all systems. Most (N = 6) were single ward studies. Two uncontrolled pretest‒post-test studies evaluating EMS that provided voice prompts showed increases in SDC, but risk of bias was high. Two uncontrolled time-series analyses of VMS that provided aggregate feedback demonstrated large, sustained improvement in SDC and were at moderate risk of bias. One non-randomized controlled trial of EMS with aggregate feedback found no difference in hand hygiene frequency but was at high risk of bias. Two studies evaluated EMS providing individual feedback and real-time reminders. A pretest‒post-test study at high risk of bias showed an increase in SDC. An RCT at low risk of bias showed 6.8% higher SDC in the intervention arm partially due to a fall in SDC in the control arm. In conclusion, the overall study quality was poor. The study at lowest risk of bias showed only a small increase in SDC. VMS studies at moderate risk of bias showed rapid and sustained increases in SDC. Data were insufficient to recommend EMS/VMS. Future studies should prioritize testing of VMS using stronger study designs including control arms and validated, system-independent measures of hand hygiene.

Low-virulence Citrobacter species encode resistance to multiple antimicrobials.

Citrobacter spp. are gram-negative commensal bacteria that infrequently cause serious nosocomial infections in compromised hosts. They are often resistant to cephalosporins due to overexpression of their chromosomal beta-lactamase. During a recent study of multidrug-resistant Enterobacteriaceae (MDRE) in solid-organ transplant patients, we found that almost half of patients colonized with MDRE carried one or more cefpodoxime-resistant Citrobacter freundii, Citrobacter braakii, or Citrobacter amalonaticus strains. Pulsed-field gel electrophoresis showed that 36 unique strains of Citrobacter were present among 32 patients. Genetic and phenotypic analysis of the resistance mechanisms of these bacteria showed that the extended-spectrum beta-lactamase (ESBL) SHV-5 or SHV-12 was encoded by 8 strains (26%) and expressed by 7 strains (19%). A number of strains were resistant to other drug classes, including aminoglycosides (28%), trimethoprim-sulfamethoxazole (31%), and fluoroquinolones (8%). PCR and DNA analysis of these multiresistant strains revealed the presence of class I integrons, including the first integrons reported for C. braakii and C. amalonaticus. The integrons encoded aminoglycoside resistance, trimethoprim resistance, or both. Despite the prevalence of MDR Citrobacter spp. in our solid-organ transplant patients, only a single infection with a colonizing strain was recorded over 18 months. Low-virulence Citrobacter spp., which can persist in the host for long periods, could influence pathogen evolution by accumulation of genes encoding resistance to multiple antimicrobial classes.

Utility of zanamivir for chemoprophylaxis of concomitant influenza A and B in a complex continuing care population.

OBJECTIVE: To describe compliance with and the safety and prophylactic efficacy of zanamivir among patients at risk of developing influenza-related complications after exposure to both influenza A and B viruses. DESIGN: Nonrandomized trial using both historical and contemporaneous controls from ward populations within the same facility. SETTING: A 547-bed urban hospital providing complex continuing care and rehabiltation. PATIENTS: Fifty patients on a single ward concomitantly exposed to both influenza A and B during an influenza outbreak. INTERVENTIONS: All patients were screened for symptoms of influenza and nasopharyngeal swabs were sent for viral culture prior to treatment (two oral inhalations [2 x 5 mg] twice daily for 5 days) or prophylaxis (two oral inhalations [2 x 5 mg] once daily for 14 days) with zanamivir. Patient symptoms, compliance, and drug tolerance were monitored daily. Demographic data, comorbidities, vaccination status, and functional status (Katz score) were collected for all patients. RESULTS: The mean age of the patients was 70.6 years (standard deviation, +/- 16.4 years). Ninety-four percent had two or more comorbidities, 71% were dependent in two or more activities of daily living, 63% had been vaccinated for influenza, and 82% had received amantadine. Zanamivir was well tolerated, with 93% of the patients completing their course. The efficacy for preventing symptomatic infection was 82% and 91% (95% confidence interval, 62% to 98%) based on historical and contemporaneous controls, respectively. CONCLUSION: These data suggest that zanamivir can be used safely and effectively as a prophylactic agent in the management of influenza outbreaks in a complex continuing care population with multiple comorbidities.

Surveillance of antibiotic resistance in invasive isolates of Neisseria meningitidis in Australia 1994-1999.

A total of 1434 strains of Neisseria meningitidis isolated from cases of invasive meningococcal disease (IMD) in Australia between 1994 and 1999 were examined by standard methods for susceptibility to antibiotics used for treatment and prophylaxis. The proportion of isolates fully susceptible to penicillin decreased from 45% in 1994 to 26% in 1999 (P<0.001). All the other isolates were less sensitive to penicillin except for two meningococci with a penicillin MIC of 1 mg/l. The geometric mean penicillin MIC increased from 0.045 to 0.065 mg/l from 1994 to 1999. There was no significant difference in the geometric mean penicillin MICs of serogroup B and serogroup C meningococci. Penicillin susceptibility was significantly associated with a poorer outcome. Isolates from survivors of IMD had a higher geometric mean penicillin MIC (0.06 mg/l) than those from fatal cases (0.048 mg/l) (P< 0.001). This suggests that factors other than the decrease in susceptibility to penicillin observed were more relevant to outcome in IMD. All isolates were fully susceptible to ceftriaxone. Rifampicin resistance was infrequent (eight isolates in 6 years) and sporadic. A single isolate had decreased quinolone susceptibility. Despite the significant shift in susceptibility to penicillin recorded, this group of antibiotics remains a suitable treatment for IMD in Australia.

The HIV-positive dentist: balancing the rights of the health care worker and the patient.

We describe a hypothetical case of an HIV-positive dentist without cognitive impairment who uses proper infection control procedures. The dentist's physician notifies the medical officer of health without the dentist's consent. Although HIV-positive health care workers, including dentists, have been identified in the past, proven HIV transmission to patients is very rare. Most authorities recommend that an HIV-positive health care worker be monitored by an expert panel, which could then, if necessary, refer to the regulatory body to revoke or restrict the person's license to practice. Mandatory HIV testing is not required for health care workers because they generally do not pose a risk for infecting their patients; they are, however, ethically and legally obligated to report their HIV status to their profession's regulatory body.

A comparison of multifaceted versus Clostridium difficile-focused VRE surveillance strategies in a low-prevalence setting.

We compared our current screening strategy for vancomycin-resistant Enterococcus (VRE) with a focused strategy that screens all stool samples sent for Clostridium difficile toxin assay but limits rectal swab screening to wards with new VRE cases detected via C. difficile samples. The proposed strategy detects 72.7% of new VRE cases, with substantial cost savings.

A blinded comparison of three laboratory protocols for the identification of patients colonized with methicillin-resistant Staphylococcus aureus.

OBJECTIVE: To compare three laboratory screening protocols for the detection of methicillin-resistant Staphylococcus aureus (MRSA) from surveillance specimens (mannitol-salt agar containing 2 microg/mL of oxacillin [MSA-2], mannitol-salt agar containing 4 microg/mL of oxacillin [MSA-4], and a broth-containing protocol as recommended by the American Society for Microbiology [M-ASM]). DESIGN: Blinded comparative laboratory study and cost analysis. SETTING: University-affiliated microbiology laboratory. METHODS: Outcome measurements included rate of detection of MRSA-positive specimens and patients, turnaround time, and media and technologist costs. All MRSA culture swabs obtained from any patient site from November 1998 to April 1999 were included. RESULTS: The M-ASM protocol detected between 19.1% and 32.0% more MRSA-positive specimens and between 13.3% and 23.3% more MRSA-positive patients per surveillance event than the MSA-4 and MSA-2 protocols, respectively. There was no difference in positive-culture reporting time between the M-ASM and MSA4 protocols. The broth-containing protocol was 2- to 2.5-fold more expensive than the simpler protocols, taking into account media and laboratory personnel costs. CONCLUSIONS: It remains to be determined whether it is cost beneficial for a hospital to adopt the M-ASM, as the potential cost of MRSA transmission from unidentified MRSA-colonized patients is unknown. A broth-containing protocol should be considered the gold standard in future studies examining newer MRSA screening protocols

Is methicillin-resistant Staphylococcus aureus an emerging community pathogen? A review of the literature.

OBJECTIVES: To discuss the historical epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) and review the literature suggesting that MRSA has become a community pathogen. DATA SOURCES: A search of the MEDLINE database was performed, encompassing all English or French language citations from 1966 to 1999 and containing the subjects and/or text words: 'Staphylococcus aureus', 'methicillin resistance', 'endocarditis', 'cellulites', 'pneumonia' and 'community-acquired'. Articles published in other languages that provided English or French abstracts were included. All relevant references cited in articles obtained from the MEDLINE database and book chapters were also included. DATA EXTRACTION: All articles obtained from the above sources were examined and were included in the review if a laboratory or epidemiological study of community-acquired MRSA was presented. DATA SYNTHESIS AND CONCLUSIONS: MRSA has emerged over the past 30 years to become a worldwide nosocomial pathogen and has recently been reported as a cause of community-acquired infections. The changing epidemiology of MRSA is likely because of two mechanisms: the movement of nosocomial MRSA strains into the community and the de novo appearance of community strains resulting from the transfer of genetic material from methicillin-resistant Gram-positive organisms to sensitive S aureus strains. The emergence of MRSA as a community pathogen has occurred at a slower rate than it did for penicillin-resistant S aureus (PRSA) in the 1950s and 1960s, possibly because the mechanism of methicillin resistance does not exhibit the same ease of transferability as that of penicillin resistance. Four case reports, seven case series, 10 case-control studies and two cohort studies on community-acquired MRSA were analyzed. Determining whether these reports involve new community-acquired strains rather than previously acquired nosocomial strains can be problematic. It appears, however, that MRSA strains of both nosocomial and community origin are now endemic in certain communities in different parts of the world. Few surveillance studies of nonhospitalized patient populations have been performed to date; thus, the true prevalence of MRSA in the community at large is essentially unknown, although it appears to be low. At present, the empirical treatment of community-acquired S aureus infections with a beta-lactamase-stable beta-lactam antibiotic is appropriate for most populations. However, empirical vancomycin therapy for serious S aureus infections should be strongly considered for patients with significant risk factors for previously-acquired nosocomial MRSA or for patients belonging to outpatient populations with a proven high prevalence of MRSA. Increasing vancomycin use will likely have a significant impact on the development of resistance in Gram-positive organisms.

Group B streptococcal necrotizing fasciitis and streptococcal toxic shock-like syndrome in adults.

Necrotizing fasciitis, which is a severe and uncommon infection involving the subcutaneous tissues, is usually caused by group A streptococci. To our knowledge, however, group B streptococci (Streptococcus agalactiae) have been reported to cause necrotizing fasciitis in only 4 instances (2 involving neonates) over the past 4 decades. We report 3 cases of group B streptococcal necrotizing fasciitis in adults that occurred in southern Ontario and Quebec within a 10-month period. All 3 patients had significant underlying illness, and all required surgical debridement in addition to antibiotic therapy. One of the cases fulfilled the criteria for streptococcal toxic shock-like syndrome. Group B streptococcus has been recognized as a frequent cause of serious disease in adults. It has become evident over the past decade that invasive streptococcal infections are on the increase. We speculate that group B streptococcus has recently acquired an increased ability to cause necrotizing fasciitis and suggest that this may represent the emergence of a new clinical syndrome in adults.

Overutilization of indwelling urinary catheters and the development of nosocomial urinary tract infections.

OBJECTIVE: To assess the impact of the overutilization of indwelling urinary catheters in the emergency department on the development of nosocomial urinary tract infection. DESIGN: Prospective cohort study. SETTING: 638-bed tertiary-care hospital. PATIENTS: 118 consecutive medical and surgical admissions from the emergency department collected over 3 weeks. INTERVENTION: Catheterized patients were assessed. The completeness of documentation relating to catheter insertion and two outcomes were measured: asymptomatic bacteriuria and urinary tract infection. RESULTS: 24 (20.3%) had catheters inserted, of whom 12 (50%) were catheterized for justifiable indications. Positive urine cultures were found in 10 of the catheterized patients (42%), 5 of whom fulfilled the definition for catheter-associated urinary tract infection. Three of the five infections occurred in patients for whom catheterization was not justifiable. An order was written for catheter insertion in 62.5% of charts, while the rationale for catheterization was documented in 16.7%. CONCLUSIONS: Many nosocomial urinary tract infections are due to the inappropriate placement of indwelling urinary catheters in the emergency department. The prevention of these infections should begin with restricting catheterization to those patients for whom it is appropriate.

Optochin revisited: defining the optimal type of blood agar for presumptive identification of Streptococcus pneumoniae.

To determine the optimal media for optochin susceptibility testing of Streptococcus pneumoniae, we measured inhibition zones for 72 S. pneumoniae and 22 Streptococcus viridans isolates on three blood-containing media. Because 15.3, 0, and 22.2% of S. pneumoniae organisms were misidentified on Columbia agar, Trypticase soy agar (TSA), and Mueller-Hinton agar, respectively, each containing sheep blood, we recommend that TSA-sheep blood agar be used.

Intermixing of dipalmitoylphosphatidylcholine with phospho- and sphingolipids bearing highly asymmetric hydrocarbon chains.

We have used high-sensitivity differential scanning calorimetry to investigate the mixing of dipalmitoylphosphatidylcholine (DPPC) with N-lignoceroylgalactocerebroside, N-lignoceroylsulfogalactocerebroside and 1-lauroyl-2-lignoceroylphosphatidylcholine. These three lignoceroyl species, whose two hydrocarbon chains are quite discrepant in length, are completely miscible with DPPC in the liquid-crystalline state. Mixtures of all three lignoceroyl lipids with DPPC show phase separation in the gel state, which is observed over a limited range of compositions (from less than 10 mol% to just over 40 mol% sulfatide) in the case of N-lignoceroylsulfatide and over a wide range of compositions in the cases of N-lignoceroylcerebroside (less than 10 mol% to greater than 90 mol% cerebroside) and 1-lauroyl-2-lignoceroyl-PC (roughly 10 mol% to 90 mol% lauroyl/lignoceroyl PC). The extensive solid-solid phase separation observed in mixtures of DPPC and 1-lauroyl-2-lignoceroyl-PC, which show eutectic behavior, is somewhat unexpected given the similar transition temperatures of the two components but appears to reflect the ability of the lignoceroyl species to form an interdigitated gel phase. However, we find no evidence that the N-lignoceroylsphingolipids are markedly more prone to segregate laterally in PC-rich bilayers than are previously studied sphingolipid species with shorter N-acyl chains. We suggest on the basis of these results that the primary biological importance of the very long N-acyl chains found in many sphingolipids may lie in some function other than the promotion of lateral segregation of sphingolipid-enriched domains in biological membranes.

Partitioning of exchangeable fluorescent phospholipids and sphingolipids between different lipid bilayer environments.

Exchangeable phospho- and sphingolipid probes (phosphatidylcholine, -ethanolamine, -serine, and -glycerol, phosphatidic acid, sphingomyelin, cerebroside, and sulfatide) have been synthesized in which one acyl chain is substituted with a fluorescent bimanyl, 7-(dimethylamino)coumarin-3-yl, or diphenyl-hexatrienyl group. The distribution of these probes between two different populations of lipid vesicles can be readily monitored by fluorescence intensity measurements, as described by Nichols and Pagano [Nichols, J. W., & Pagano, R. E. (1982) Biochemistry 21, 1720-1726], when one of the vesicle populations contains a low mole fraction of a nonexchangeable quencher, (12-DABS)-18-PC. The probes examined in this study exchange between phospholipid vesicles on a time scale of minutes, with kinetics indicating that the transfer process takes place by diffusion of probe monomers through the aqueous phase. As expected, lipid probes with different charges differ markedly in their equilibrium distributions between neutral and charged lipid vesicles. However, probes with different polar headgroups differ only modestly in their relative affinities for vesicles composed of "hydrogen-bonding" lipids (PE and PS) vs "non-hydrogen-bonding" lipids (PC and PG or O-methyl-PA). Probes with different headgroups also show modest, albeit reproducible, differences in their relative affinities for cholesterol-containing vs cholesterol-free PC/PG vesicles. Our results suggest that lipids with different headgroup structures may mix more nearly ideally in liquid-crystalline lipid bilayers than would be predicted from previous analyses of the phase diagrams for binary lipid mixtures.

The NADP-dependent trifunctional methylenetetrahydrofolate dehydrogenase purified from mouse liver is immunologically distinct from the mouse NAD-dependent [corrected] bifunctional enzyme.

Methylenetetrahydrofolate dehydrogenase - methenyltetrahydrofolate cyclohydrolase - formyltetrahydrofolate synthetase was purified to homogeneity from mouse liver, taking advantage of its very high affinity for 2',5'-ADP-Sepharose. Antibodies raised to this trifunctional enzyme and to the bifunctional NAD-dependent dehydrogenase-cyclohydrolase from mouse Ehrlich ascites tumour cells were found not to cross-react with the purified proteins on Western blots. Each of these polyclonal antibodies detects the appropriate protein in extracts of Ehrlich ascites tumour cells after sodium dodecyl sulfate - polyacrylamide gel electrophoresis and electrophoretic transfer of the proteins to nitrocellulose. The procedure has also been used to obtain a purified preparation of the trifunctional enzyme from human liver obtained at autopsy.