In healthcare settings, surveillance is a critically important component of any multidrug-resistant organisms (MDRO) control program. Multiple MDRO surveillance strategies, including measures for exposure burden, healthcare acquisition, and infection burden, have been employed. No consensus for MDRO surveillance metrics has been achieved in Japan; as a result, data collection and definitions for calculating those metrics vary widely between healthcare facilities. This document describes useful and practical surveillance metrics and issues to consider when using those metrics in practice for infection prevention and control in healthcare settings.

In September 2013, an outbreak of hospital-acquired Legionella pneumonia caused by the L. pneumophila serogroup 1 was confirmed. An investigation resulted in suspecting the infection source to be a hot water-supply system because the banding pattern on pulse-field gel electrophoresis of Legionella DNA from the hot water in patients' rooms matched with that of the sputum sample collected from patients. In addition, the investigation of the contaminated hot water-supply system detected L. pneumophila SG 1 from one of the mixed-water faucets. As disinfection measures, after disinfection, hot water was continuously discharged to prevent the temperature of the hot water in the distribution pipe from decreasing. Moreover, unnecessary pipes were removed, which successfully eliminated the bacteria. However, the L. pneumophila SG 1 contamination was detected again from the 40°C-mixed water, leading to investigation at 92 places. Consequently, the same bacteria were detected at 23 places, and the contamination of the water-supply system was confirmed. As disinfection measures of the water supply system, sodium hypochlorite was continuously added to the water-receiving tank to maintain the free residual chlorine concentration at ≥0.87 mg/L at the mixed-water faucets. Furthermore, water was discharged from the most distal mixed-water faucet for 6 minutes and from all hospital room washbasin faucets for 1 minute every day. These measures increased the free residual chlorine concentration to an average of 0.81 mg/L (P<0.01), and the detection rate of the same bacteria decreased from 13.6% to 0.4% (P<0.01), confirming the efficacy of the measures. This study suggests that an investigation should be conducted considering the possibility that the water-supply system may be the source of contamination when Legionella contamination in the hot water-supply system is detected.

In 2014, the second edition of the Vaccine Guideline for Healthcare Professionals (Guideline below) was released. According to the guideline, we investigated the history of immunization and management of virus antibody titers for measles, rubella, varicella, and mumps. The infection control team collected copies of maternal and child healthcare handbooks from officials and information on their past virus antibody titers. Subsequently, we created a database with information on the results of the virus antibody titers used at our hospital.

The submission rate of copies of maternal and child healthcare handbooks was 8% of the incumbent and 60% of the new recruits. For the antibody titers, information was collected from electronic medical charts. According to the guideline, cases suitable for immunization were categorized into the three following groups: first, those with two vaccination records; second, those whose antibody titers satisfied the criteria twice, and third, those with antibody-positive vaccination that did not meet the criteria. We decided as immunized enough were follows, 155 (33%) of measles, 145 (30.9%) of rubella, 116 (24.7%) of varicella, and 115 (24.5%) of mumps. In many cases, the vaccination record could not be confirmed. This is because of the many lost maternal and child healthcare handbooks and many inadequate vaccination records after adulthood. In our hospital, we created a database of vaccination history and antibody titers of all the staff members. Every year, the infection control team evaluates and informs about recommended measures, making it possible for hospitals and individuals to manage. Henceforth, we propose to manage them in a common format for healthcare professionals.

Antimicrobial resistance has been a problem worldwide and because of this, each medical institution is required to gather evidence of antimicrobial agent usage and its compatibility with the bacteria. Although the dental ward at the Niigata University Medical and Dental Hospital are advancing in antimicrobial management, antimicrobial prophylactic oral agents in the dental outpatient clinic was left to the discretion of the dentists. However, there are other unanswered questions. Therefore, the aim of this study was to evaluate the management of the antimicrobial agents' usage review and surgical site infection (SSI) status for the dental outpatient clinic from the perspective of a pharmacist. During January 2012-December 2016), we retrospectively analyzed the simple extraction of permanent tooth with the presence or absence of antimicrobial prophylactic agent, type, dosage, and SSI. We found that antimicrobial prophylactic agents were administered in approximately 70% of the patients in the dental outpatient clinic for an average of 3 days, 80% of which used third-generation cephalosporins. On the other hand, there was no significant difference in SSI with regard to the presence or absence of antimicrobial prophylactic agents. Therefore, antimicrobial prophylactic agents may not affect the SSI after a simple tooth extraction. According to the guideline, antimicrobial prophylactic agents are not recommended for simple tooth extraction and the first choice of antimicrobial prophylactic agents are penicillin; therefore, we have to advance antimicrobial management in our dental outpatient clinic.

Respiratory infection is the leading cause of death in patients with severe motor and intellectual disabilities (SMID). The purpose of this study was to elucidate the measures being taken to combat respiratory infection in institutions for patients with SMID. The subjects included one person responsible for Ryouiku and one person responsible for nursing at each of the 202 institutions for patients with SMID in Japan. Self-administered questionnaires were sent to the subjects via mail. Ryouiku surveys were collected from 120 institutions (59%) and nursing surveys from 112 institutions (55%). Approximately half of the institutions had gone through outbreaks of respiratory infections in the past year, during which group Ryouiku with patients showing symptoms of infection and joint Ryouiku among multiple wards had been cancelled. Group Ryouiku and activities on the floor were practiced at many of the institutions, suggesting that the respiratory infection transmission route was via therapy mats and toys. Symptom screening to prevent people from bringing in infectious disease was conducted at a high rate for student apprentices but not at a sufficient rate for staff, teachers, and volunteers. Therefore, in the future, it will be necessary to promote symptom screening and respiratory syndrome surveillance.

This study aims to investigate the contamination of wipe towels by Bacillus cereus and the washing methods followed by multiple facilities to determine whether different washing methods affect the B. cereus contamination of reusable cloth wipe towels. In addition, this study assesses the correlation between the B. cereus contamination of wipe towels and blood culture results. Subject facilities included six hospitals in the Niigata Prefecture. We collected three dry wipe towels from each hospital per month to assess the B. cereus bacterial concentration. Moreover, we surveyed the washing and storage methods of wipe towels and the number of B. cereus-positive cases from the blood culture results. The bacterial concentration in each facility was in the range of 0-1142 CFU/mL, and we observed a positive correlation (R=0.72, P=0.11) between the average bacterial concentrations and the rates of positive-blood culture results. With respect to the washing methods, the bacterial concentration tended to be lower when a batch method was followed compared with when a continuous method was followed. The B. cereus concentration was significantly lower when the washing process involved soaking in sodium hypochlorite (P<0.01). Thus, the B. cereus contamination of wipe towels was affected by a difference in washing methods, and it may affect the rates of positive-blood culture results. This study suggests that in a facility with a large number B. cereus-positive cases, the number could be decreased by confirming and changing the washing method, which may decrease the bloodstream infection by B. cereus.

Despite being high-frequency contact surfaces, it is difficult to perform daily environmental maintenance and disinfection in hospital room privacy curtains and they are likely to serve as potential sources of secondary infection. In the present study, the antibacterial effect of an alcohol-based silver antibacterial agent was verified by spraying it on 40 target cloth curtains at a surgical hospital ward. The samples were collected from the surfaces of curtains on days 1, 7, 14, and 28 after the start date. The mean increased amount of bacteria calculated after 28 days was 15 CFU/100 cm² with the agent and 106 CFU/100 cm² without the agent, showing a statistically significant difference (p<0.01). Therefore, the antibacterial agent used may have a lasting disinfectant effect on hospital room privacy curtains. The silver antibacterial agent can be considered effective in reducing the risk of infection in hospital privacy curtains.

The number of patients with methicillin-resistant Staphylococcus aureus (MRSA) colonization in our neonatal intensive care unit (NICU) has rapidly increased since March 2016; therefore, we suspected horizontal MRSA transmission. Although infection control practices, including strengthening contact precaution measures and patient cohorting were implemented, MRSA transmission was not controlled. We decontaminated MRSA-colonized staff and treated the patients; subsequently, MRSA transmission and increased colonization were controlled. Cases of MRSA infection were not observed during the period when infection control measures were effectively applied. A PCR-based ORF typing (POT) analysis revealed eight different MRSA strains, and four-eights of strains transmitted in NICU. The suspected transmission route generated using the two-dimensional career map system (2DCM-web) completely coincided with POT results. Therefore, 2DCM-web is believed to be a useful tool to detect transmission routes. In the present case, our prompt actions terminated an outbreak and prevented subsequent MRSA infections. MRSA infection can be contracted from external sources at any time; therefore, NICU staff should regularly perform infection control practices.

Introduction: In this study, we used polymerase chain reaction-based open reading frame typing (POT) to estimate the horizontal transmission pathway for methicillin-resistant Staphylococcus aureus (MRSA) detected in routine nasal surveillance culture in neonatal and pediatric wards.

Methods: The horizontal transmission pathway for MRSA cases detected at Osaka Women's and Children's Hospital during July 2015-July 2016 was estimated using POT and antibiotic resistance patterns.

Results: Of the hospitalized patients with MRSA, 81 were classified as "in-hospital acquired," and of these patients, 33 shared a history of hospitalization in the same ward during the same period (7 POT types), thereby indicating horizontal transmission. In the neonatal ward, of the 42 patients with MRSA, the number of horizontal transmission cases was 3 (22 patients), whereas in the pediatric cardiovascular ward, the number of horizontal transmission cases was 4 (11 patients). The antibiotic resistance patterns in similar POT types were consistent with all strains in the case of horizontal transmission. None of the MRSA POT type obtained from nasal cavity culture of the ward staff at the onset of the outbreak matched with the POT type of patient-derived MRSA samples.

Conclusions: We could distinguish multiple cases of horizontal transmission at similar durations in the same ward using POT. Therefore, this method can be useful for understanding the horizontal transmission of MRSA within a ward.