The Ministry of Health, Labour and Welfare has officially released various notices that serve as guides on healthcare-associated infection prevention and control. The notice issued in 1991, when methicillin-resistant Staphylococcus aureus infection had caused havoc, emphasized general infectious disease control measures at clinical facilities. The notice issued in 2005 placed importance on infectious disease measures based on evidence, and the notice issued in 2011 discussed the fundamentals of activities carried out by infection control teams, mutual collaboration among healthcare facilities, and the definition of outbreak of infectious disease and its notification. The notice issued in 2014 described the basic concept of antimicrobial resistant strains, and subsequently the organization of infectious disease control and regional medical collaboration developed rapidly. The present study discusses how the notices issued by the Ministry of Health, Labour and Welfare have helped develop and modify measures and policies associated with infection prevention and control in Japan, and summarizes the transition of basic Japanese concepts on various problems related to infection.

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 The history of the use of disinfectants is discussed, such as the beginning of use, and the understanding of use for the prevention of infection. In the 1840s, finger hygiene with chlorinated lime was initiated, which was replaced by the use of phenol or mercuric chloride. In the latter half of the 1870s, the cause of infection by microorganisms was demonstrated. Since then, the importance of disinfectants has become widely recognized. In 1990, advances in synthesis technology allowed many disinfectants to be synthesized, including those used at present. The ideas of Semmelweis IP and Lister J, who proposed the prevention of contact infection, continue to be the basis for the use of disinfectants. We describe the methods of finger hygiene, environmental disinfection, and instrument disinfection.

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 A computerized decision support program for isolation precaution was developed based on a conceptual framework of the problem-solving process for appropriate isolation precaution measures by certified nurses in infection control (CNICs). This study evaluated the effectiveness of the program for infection control practices of novice CNICs and health care-associated infections (HAIs). A randomized controlled trial was conducted with 187 novice CNICs. Finally, 28 CNICs participated after providing informed consent. The baseline and intervention periods were from January to April 2012 and from May to August 2012, respectively. The experimental group was asked to use the computerized decision support program in their infection control practices during the intervention period. Data of infection control practices and HAIs were collected from both groups. No significant differences in the incidence rate of methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile infection (CDI) and number of outbreaks were found between the 2 groups. The program was used for 92 HAI cases and was considered helpful in 72 cases. Based on the analysis of descriptive data, the program was useful for novice CNICs in infection control practices for risk assessment of infection, decision and implementation of isolation precautions, support for decision making, and as a reference and educational tool.

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 Various rub-in hand disinfectants have been developed for hygienic and surgical hand disinfection. In this study, the immediate and persistent effects of 1.0 w/v% and 0.5 w/v% chlorhexidine gluconate/ethanol preparations (1.0% CHG–AL and 0.5% CHG–AL, respectively) on the numbers of bacteria on the hands of 41 experienced nurses were investigated using the glove juice method. 1.0% CHG–AL and 0.5% CHG–AL exhibited significantly greater efficacy than 0.2 w/v% benzalkonium chloride/ethanol preparation immediately and 3 hours after disinfection (p≤0.05, Fisher's exact test). The most common microorganisms isolated in this study were coagulase-negative staphylococci (CNS) and Bacillus spp. Immediately after and 3 hours after disinfection with 1.0% CHG–AL, the counts of CNS were significantly reduced by 180– and 170–fold, respectively, compared with those seen before disinfection (p≤0.05, Student's t-test). Immediately after and 3 hours after disinfection with 0.5% CHG–AL, the counts of CNS were significantly reduced by 513–fold, compared with those detected before disinfection (p≤0.05, Student's t-test). Immediately after and 3 hours after disinfection with 1.0% CHG–AL, the counts of Bacillus spp. were significantly reduced by more than eleven- and seven-fold, compared with those observed before disinfection, respectively, but 0.5% CHG–AL had no effect on the counts of these bacteria. In comparisons between the two timepoints, neither 1.0% CHG–AL nor 0.5% CHG–AL exhibited significant log₁₀ reduction factors for the numbers of total microorganisms, CNS, or isolated Bacillus spp., indicating that both disinfectants had strong persistent effects (p≤0.05, Student's t-test). Therefore, the disinfection efficacy of 1.0% CHG–AL was superior to that of 0.5% CHG–AL, based on the significantly more effective action against Bacillus spp.

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 We have started a campaign to promote appropriate implementation of blood culture in our hospital. This campaign includes lectures for medical staff and students, evaluation of patients with positive blood culture, reporting the implementation status of blood culture at infection control meetings, implementation of blood sampling by nurses, and simplification and manual revision of blood sampling. We investigated 38,813 blood culture samples obtained between January 2009 and December 2014. The number of blood culture sets, the rates of multiple sets, contamination rates and positive rates were evaluated. The number of blood culture sets increased from 3,168 sets in 2009 to 4,920 sets in 2014. Blood culture sets per 1,000 patient-days also increased from 12.4 sets in 2009 to 19.3 sets in 2014. The rate of multiple set increased from 30.6% in 2009 to 73.3% in 2014 in adult inpatients, and 43.0% to 85.7% in adult outpatients. Contamination rate was 3.5% in 2009 and decreased to 2.7–2.9% after 2010. Positive rates decreased from 15.1% in 2009 to 11.0% in 2014 in adult inpatients, from 22.2% to 18.7% in adult outpatients and from 9.4% to 2.6% in pediatrics. Positive rates of multiple sets were consistently higher than those of single sets. Our campaign promoted the appropriate implementation of blood culture and improved several parameters. Combination and continuation of multiple activities was effective for staff education and promotion of appropriate blood culture sampling.

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 To control the spread of drug-resistant microorganisms in a local community, preventive action should be based not on action at a single health-care facility but rather should involve cooperation across facilities. We explored the association between the use of antimicrobial agents and drug resistance in the eastern region of Kitakyushu-shi. The results were compared between two groups: additional reimbursement for infection prevention regional collaboration 1 and 2. We also surveyed the incidence of multidrug-resistant Pseudomonas aeruginosa in each facility. Antimicrobial use density (AUD) was measured in terms of carbapenem use. The results showed no significant difference in antimicrobial use and resistance ratio of P. aeruginosa between the two groups. Therefore, antimicrobial use was not correlated with resistance ratio of P. aeruginosa. Based on these results, infection-control measures other than the AUD of antimicrobial agents are important in controlling the susceptibility ratio. In addition, as multidrug-resistant P. aeruginosa was found in several facilities, prevention of spread of infection through inter-regional cooperation is necessary.

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 Using multiple court case search systems, we analyzed 83 reports involving the prevention and postinfection control of methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, and other infectious agents. Many of the 83 cases involved postoperative patients, and the outcome was most often death. MRSA is the most common cause of public health problems in the past 20 years (1995–2014). Problems associated with P. aeruginosa include mortality due to multidrug-resistant P. aeruginosa (MDRP). Additionally, terms such as “clinical practice guidelines,” “systemic inflammatory response syndrome,” and “Gram staining” started to appear more frequently in more recent judicial judgments. Comparison of infection preventive measures and post-infection control measures found that errors were often dismissed in the former compared to the latter. In terms of postinfection control measures, issues were related to the need for blood culture tests and selection of the appropriate antimicrobial drug. On the basis of these findings, we conclude that it is important to provide sufficient information to patients and their family members before surgery, at the detection of MRSA/MDRP infection, and after death. Furthermore, regardless of compliance with the clinical practice guidelines, the guidelines must be considered for establishing measures for infection prevention and postinfection control. Healthcare institutions must also document specific measures for infection prevention and to perform Gram staining for postinfection control.

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[in Japanese]

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