Stenotrophomonas maltophilia is an important pathogen in immunocompromised patients, such as patients with malignancies, long-term hospitalized patients, or patients receiving broad-spectrum antibiotic therapy. We confirmed an outbreak of S. maltophilia in allogenic bone marrow transplant patients in June 2007. To identify the source of the pathogens, environmental cultures were obtained from the transplantation unit. S. maltophilia strains were isolated from a bath chair, a shower head, and an automatic hot towel dispenser. Outbreak-related strains from 4 patients and 4 strains from the environment were compared by pulsed-field gel electrophoresis (PFGE). Two strains from blood cultures and one strain from the dispenser were identical, as confirmed by PFGE, which showed that the outbreak was associated with the automatic hot towel dispenser. Subsequently, many types of non-fermentative Gram-negative organisms were isolated from all automatic hot towel dispensers placed in other wards. These results indicate that medical equipment containing water requires careful attention to maintain sterility in use.
Human noroviruses(HuNoVs)are the major cause of acute viral gastroenteritis worldwide. However, no cell culture system for HuNoVs is available, so little is known about the efficacy of various disinfectants against HuNoVs. Cultivable murine norovirus(MNV)was used as a novel surrogate for HuNoVs to evaluate the efficacy of five types of chlorine-based and alcohol-based commercial disinfectants to MNV using the TCID50 method. MNV was inactivated to more than 99.998%(4.8 log10)and reached the detection limit by 200 ppm of chlorine-based disinfectants, sodium hypochlorite and dichloroisocyanuric acid sodium, with contact time of 30 seconds. Moreover, MNV was inactivated at 99.99%(4 log10)using chlorine-based disinfectants at a final dilution concentration of 125 ppm with contact time of 30 seconds. Three types of alcohol-based commercial disinfectants, 70 v/v% ethanol, 0.18 w/v% chlorhexidine gluconate with 72 v/v% ethanol, and 0.18 w/v% benzalkonium chloride with 75 v/v% ethanol, all reduced MNV to titers below the detection limit with contact time of 30 seconds. Chlorine-based disinfectants showed great efficacy against MNV even if diluted to 125 ppm. In addition, alcohol-based disinfectants had adequate efficacy against MNV if used without dilution(ethanol concentrations of more than 70 v/v%). These results suggest that these disinfectants can inactivate HuNoVs. The five types of commercially available disinfectants tested here can be used to prevent norovirus infection.
Antimicrobial agent administration during surgery is important for prophylaxis against surgical site infection. The infection control team of our hospital recommends administration of cefazolin (CEZ) or cefmetazole (CMZ) every 3 hours during surgery. However, appropriate administration was frequently not provided in surgery extending over 6 hours. We changed the supply of an antimicrobial agent from “provided by prescription” to “administered by all staff in the operation area” to improve compliance with the recommendations. In addition, “form stamps” were provided to control administration in each care unit. Administration of antimicrobial agents during surgery extending over 6 hours was retrospectively studied before (August 2005) and after (August 2006) change of the supply system, and after introducing the electronic medical recording system (August 2007). Total surgeries were 45, 46 and 44 cases, and mean operation times were 483, 524 and 510 min (p=0.46), respectively. The recommendations required 99, 114 and 106 doses, whereas the actual provisions were 20 (20.2%), 101 (88.6%) and 104 doses (98.1%), respectively (p<0.001). The mean interval between administrations was 181 min and extended over 210 min in only 2 cases. The change in supply methods including form stamps and other interventions dramatically improved antimicrobial agent administration during extended surgery.
Antimicrobial usage was monitored at our general hospital from 2001 to 2007, but the large number of medical departments have different protocols for use of antimicrobial drugs, including internal medicine, surgery, obstetrics and gynaecology. Consequently, total antimicrobial usage cannot analyze the actual situation of antimicrobial usage. The present study investigated the density of antimicrobial use (AUD) in each department, to clarify factors in any differences. Some groups of antimicrobial drugs were used at different frequencies and transitions depending on the guidelines followed in each department. Total antimicrobial usage in this hospital was greatly influenced by internal medicine use, so the antimicrobial usage in each department is important in analysis intended to change antimicrobial usage.
Promotion of appropriate use of antimicrobial agents is one of the most important problems in nosocomial infection control. Our institution started a restriction program for broad-spectrum antimicrobial agents (fourth-generation cephalosporins, carbapenems, quinolones, and anti-MRSA agents) from April 2006. As a result, the consumption of fourth-generation cephalosporins and carbapenems decreased, and prescription of chronic medication lasting for 14 days or more also decreased. Moreover, we began the distribution of materials concerning antimicrobial use based on pharmacokinetics/pharmacodynamics properties in April 2008. Since then, the mode of administration of 1000 mg×3 times/day and 2000 mg×twice/day has increased for cefozopran (CZOP) and the mode of administration of 500 mg×3 times/day has increased for meropenem (MEPM). The drug-resistance rate to CZOP of Pseudomonas aeruginosa increased temporarily compared with 2005 in 2006, but recovered to the same level compared with 2005 in 2007. Moreover, the drug-resistance rate to MEPM of P. aeruginosa decreased every year. Therefore, positive intervention by the infection control team is important for promotion of appropriate antimicrobial use and preventing increase in drug resistant bacteria.
Measles antibody levels were measured for age-stratified analysis in the 530 staff of our hospital. Antibody measurement was performed by the gelatinous particle agglutination test (particle agglutination: PA method) and enzyme linked fluorescent assay (ELFA) method. The correlation between these methods suggested that the inexpensive and easy PA method was adequate for measurement of measles antibody levels. Staff were divided into 3 groups, antibody negative group (8 times or below), inadequate antibody positive group (16-64 times) and adequate antibody positive group (128 times or more). The mean age was 27.29±5.35 years, 41.05±13.69 years and 37.70±11.63 years, respectively, indicating that the negative antibody group was significantly younger. The mean measles antibody level by the ELFA method was 1.83±0.94 in staff aged 29 years old or under, and significantly lower than 2.60±1.12 in staff aged 30 years old or over. Measles vaccination involves regular inoculation in people 29 years old or under, so a relationship with vaccination was indicated. One staff member was considered to have secondary vaccine failure. People aged 18 years old or under have become the target for vaccination twice against measles, but people 19 years old or over are not the target for regular second inoculation. To reduce the population with secondary vaccine failure as far as possible, an antibody test should be conducted before commencing employment at a medical institution, and vaccination repeated if necessary to prevent infection or becoming an infection source.
The 8th session of “Alternatives and Management of Indwelling Catheters” was recently held within the framework of the “Program for Educating Home-Visiting Nurses on Infection Control” (a series scheduled to consist of 12 sessions). A process of analysis and evaluation was carried out to ascertain what the attendees learned during the workshop. The workshop was attended by 20 home-visiting nurses working at 2 visiting nursing stations. The workshop, lasting for one hour, was held on a weekday evening at both stations. The effectiveness of this workshop in facilitating learning was evaluated by analyzing changes in the knowledge/skill level of nurses about 27 items related to alternatives and management of indwelling bladder catheters before the workshop (pre-workshop knowledge/skill level) to that after the workshop (post-workshop knowledge/skill level). The knowledge/skill level was rated on a five-point scale: score 1 (completely incapable) to score 5 (thoroughly capable). The mean score for each item was calculated, and the pre-workshop and the post-workshop mean scores were compared using the Wilcoxon rank sum test. Analysis of the score in relation to the background variables of the nurses was carried out using Spearman's rank correlation coefficient. The mean of the total score for 27 items increased from 3.6 (before workshop) to 4.6 (after workshop). The scores for all individual items increased the after workshop and was statistically significant for 26 items. Analysis of the scores in relation to the background variables of the nurses showed correlations between the pre-workshop score on 10 items and the length of careers as nurses in general, and between the post-workshop score on 2 items and the length of careers as home-visiting nurses. The workshop was useful in improving the knowledge/skill level of the home-visiting nurses about alternatives and management of indwelling bladder catheters. The next step is to review and modify the methods of training on the items with insufficient improvement.
Correct handwashing is essential for infection control, so pharmaceutical students must acquire appropriate handwashing skills before entering clinical practice. We introduced a handwash education system to our training for two hundred students in the later period of the third grade, and evaluated the outcomes. First of all, students applied fluorescent lotion to both hands, and performed social handwashing with soap and running water. The remaining fluorescent areas were then sketched to assess the effectiveness of handwashing. The students then received a lecture which referred to the importance of hand hygiene, the type and the purpose of handwashing, and the procedure of hygienic handwashing. Next, students tried hygienic handwashing with soap and running water, and the fluorescent areas were sketched again. Fluorescent areas were totaled as a number of students, and the result of handwashing were compared before and after the lecture. Moreover, we distributed a questionnaire on the understanding of handwashing to the students. The time required for training was very short, but the students gained good understanding of hygienic handwashing, and became conscious of good habits and difficult areas to wash. We would like to raise awareness of hand hygiene and to encourage good habits of handwashing through enriched and repeated practice in the upcoming six-year program of pharmaceutical education.