We routinely perform microbiological surveillance of endoscopes (upper gastrointestinal endoscopy, colonoscopy, and bronchoscopy) to monitor the quality of reprocessing procedures (cleanliness survey) at our facility. We perform bacterial stain and culture of samples obtained by flushing with sterile saline through biopsy channels of endoscopes that were stored after reprocessing in this survey. We describe the result of this cleanliness survey through 2008 to 2016.
The positivity rates in bacterial isolation for 9 years in upper gastrointestinal endoscopy and colonoscopy were 21.4% and 13.8%, respectively. The annual positivity rates in upper gastrointestinal endoscopy and colonoscopy were 0-44.0% and 0-29.2%, respectively, which considerably decreased after 2013. In the years when microorganisms were detected frequently, we found that identical endoscopes were repeatedly positive for any organisms. No organism was detected from bronchoscopy. For the culture-positive endoscopes, after repeating cleaning and disinfection process, we reexamined them. The overall positivity rates in upper gastrointestinal endoscopy and colonoscopy were 4.4% and 3.0%, respectively. The annual positivity rates in upper gastrointestinal endoscopy and colonoscopy were 0-12.5% and 0-8.3%, respectively. The microorganisms that were detected after reexamination were almost identical in species to those that were isolated before the repeated reprocessing process. In spite of our efforts to investigate the cause, a possible reason for the failure in disinfection was unapparent.
After 2013, the annual rates decreased. However, in some endoscopes, even after repeated cleaning and disinfection, occasionally, microorganisms were detected. It seems difficult to remove microorganisms completely from the biopsy channels of endoscopes by the current method of cleaning and disinfection. The cleanliness survey requires us to uncover the cause of endoscope contamination and to prevent endoscope-associated infection.
An important issue that is related to infection control is the spread of extended-spectrum β-lactamase (ESBL)-producing bacteria. Although, in addition to carbapenems, cefmetazole and flomoxef have been shown to be effective against the hydrolyzing activity of ESBL in vitro studies, the clinical studies that have evaluated their role against infection and pathogenicity caused by these organisms are few. Therefore, we evaluated the status of the isolation of ESBL-producing bacteria in Showa University Northern Yokohama Hospital and the factors associated with the efficacy of the treatment for the infections these organisms cause.
Between April 2008 and March 2016, ESBL-producing bacteria were isolated from 132 patients. A total of 128 patients were treated with antimicrobial agents for more than 3 days. No significant differences in the 30-day mortality rates were observed between the responsive group and the non-responsive group. On the one hand, in the responsive group, there were significantly more number of urinary tract infections and patients who used carbapenems. On the other hand, in the responsive group, the number of respiratory tract infection cases was significantly low. Multivariate analysis confirmed the use of carbapenems as being significantly associated with the efficacy of treatment (odds ratio, 3.73; 95% confidence interval, 1.34-10.35; P = 0.012).
Carbapenems are recognized as the first-line drug for infections with ESBL-producing bacteria. However, the usage of carbapenems should be well controlled. It is necessary to de-escalate their use when ESBL-producing bacteria are identified as non-causative pathogen.
In Japan, there are no established standards for the quality of water that is supplied from a dental unit, and there have been no published reports about contamination of the dental unit with Legionella bacteria, showing a lack of interest in such contamination by medical personnel. In our hospital, as part of our countermeasures to prevent hospital infection, we have been regularly performing an environmental investigation on Legionella in water supply system of the hospital since 1997, and, in 2014, we added the water supply from the dental units to this environmental investigation. From dental unit No. 2, 60 CFU/mL of Legionella sp. was detected, and more than 1,000 CFU/mL of Legionella sp. was detected in individual sites, such as the gargle water, the low-speed handpiece, and the air water 3-way syringe of the unit. The following countermeasures were taken. We discontinued the warming of the supplied water. Flushing of the circuit was performed, and dilute sodium hypochlorite was discharged. However, the level of Legionella sp. did not fall below measurable detection limits. We were compelled to replace the unit because, due to the structure of the unit, further countermeasures, such as high temperature sterilization and use of high-concentration antiseptic drug, could not be added.
Most cases of Legionella infection in recent years have been reported as single domestic cases without any obvious source of the infection, which suggests that there is the possibility of previously unrecognized sources of infection. An extremely high potential risk of Legionella infection may be provided by the water supply from a dental unit to produce aerosol.
The hope is that there will be cooperation among the manufacturers of dental units, usage administrators, and the government to establish appropriate management standards and methods to prevent contamination, to control contamination caused by water supply from dental units and to prevent Legionella infection.
Worldwide, the number of SMID (severe motor and intellectual disabilities) patients continuously in need of profound medical care, such as mechanical ventilation, are increasing. Infection control is of great importance since such patients have high risk of multidrug resistant organism colonization. On the other hand, SMID wards have an "at home" atmosphere, and various specialists, including co-medicals, helpers and child-carers are directly involved in taking care of patients. Therefore, it is difficult to permeate hand hygiene awareness throughout the staffs. The SMID wards in our hospital are not the exceptions and the consumption rates of AHR have been very low. After experiencing a two drugs resistant Acinetobacter baumanii (2DRA) outbreak in 2014, we started to implement the WHO multimodal hand hygiene improvement strategy in 2014, applying both "the step-wise approach" and "the five components of the WHO multimodal hand hygiene improvement strategy". The AHR consumption volume (mean value in a year) in ward A was 2.9 (2012), 4.2 (2013), 10.1 (2014), 15.0 (2015), and 26.7 L/1000patient/days (2016), and in ward B, 2.2, 2.8, 5.5, 11.8, 18.6 L/1000patient/days, respectively. Although " 'My 5 Moments for Hand Hygiene' approach" is the most famous component in this strategy, we found that "the step-wise approach" which shows how to initiate and renew periodically a comprehensive hand hygiene program, was also critical to make a smooth start, and to sustain the improvement of hand hygiene. In addition, for an effective improvement in hand hygiene, the prioritization and modification of the tools in "the five components of the WHO multimodal hand hygiene improvement strategy" and "Hand Hygiene Self Assessment Framework" was important.
Well-known causes of healthcare-associated infection of Aspergillus in compromised hosts such as neutropenic patients are hospital construction and renovation. To reduce the risk of infection, infection control risk assessment (ICRA) followed by the establishment of a protective environment (PE) has been recommended. In 2010, during the construction and renovation (2006-2013) of a teaching hospital in Miyazaki, Japan, increased positivity of Aspergillus in samples from patients was recognized. This event was considered to be due to pseudo-outbreak of Aspergillus because the number of patients clinically diagnosed with aspergillosis did not increase. ICRA and PE practices were reviewed by the infection control team. Following this, measures such as barriers to prevent the airborne dissemination of Aspergillus were improved, and the frequency of Aspergillus positive samples from patients decreased. This experience re-emphasized the importance of ICRA before the start of hospital construction and renovation followed by adequate measures such as barriers to prevent airborne dissemination, and the monitoring of markers for aspergillosis.
To reduce the risk of occupational infections caused by blood and body fluid splashes to medical staff, the appropriate use of personal protective equipment is important. However, previous reports revealed that the wearing rate of goggles to protect the ocular mucosa is less than that of gloves and masks. According to the "Report of JES 2015 Epinet B exposure (skin mucosal exposure) ", nurses accounted for more than half (60%) of medical staff who reported skin mucosal exposure, and the eye (67.2%) was the most frequently contaminated tissue. Therefore, in both the cardiovascular and cardiovascular surgery wards, sources of high risk of transmission of infection due to surgical procedures, we hold study sessions for all the staff to educate them on the proper usage of goggles, including the creation of a checklist based on the "Recommendation of CDC guidelines 2007 for precautionary measures on medical practice", and conducted monthly self-assessment, as well as an evaluation by other staff members every 3 months. The average goggles wearing rate increased from an initial rate of 39.6%, 3 months after the development of the study group, to 70.5% in 6 months, with the standardization of wearing goggles. To prevent ocular mucosal exposure, there is the need to educate both management and the medical staff about the importance of the use of goggles.
Around October each year, when the outbreak of influenza is expected, medical institutions and other health facilities strengthen preventive measures. At our hospital, in the second week of Heisei 26 (fiscal Heisei 25), outbreaks of influenza exceeded 10% on the same floor. Based on this experience, we focused on two of the initial responses. First, we bundled the awareness-raising activities for the staff on a monthly basis, and used an "influenza preventive measure calendar" to inform each division. Next, to promote the standardization of the response to the person who has a fever, the correspondence has been made into a flowchart. In fiscal Heisei 26, horizontal infection was recognized in one department, but was contained without the expansion of the infection to other wards. In fiscal Heisei 27, based on the lessons learned from the previous year, we added restrictions on interactions among patients to the bundle and got results without any further outbreaks.