During the COVID-19 pandemic, not only emergency physicians but also all healthcare workers faced the risk of nosocomial infection. In our hospital, all the physicians, including anesthesiologists and intensivists, performed tracheal intubation on COVID-19 patients. Initially, an open-type intubation box was used for the tracheal intubation of COVID-19 patients to prevent infection and spread of contamination to the surrounding area, but problems, such as aerosol leakage to the surrounding area, arose. Therefore, we had to find a new strategy for intubation and develop a new device. Faced with such a situation, Toho University, in collaboration with a dust mask company, has developed a disposable intubation box with a high-performance filter that adds a strong negative pressure. In this paper, we would like to summarize the development process from the perspective of nosocomial infection prevention.

The current coronavirus disease 2019 (COVID-19) pandemic has highlighted the importance of cleaning and disinfection of environmental surfaces. Bioshell calcium oxide water (BiSCaO Water) is a concentrated solution of calcium oxide derived from scallop shells and has a high pH (≥12.7). So far, BiSCaO Water has been shown to exhibit broad microbicidal activity and to be friendly to the living body and the environment. This study aimed to explore the potential use of BiSCaO Water for the disinfection of environmental surfaces compared with ethanol and hypochlorous acid (200 ppm, pH 6.2). Investigations based on adenosine triphosphate (ATP)-based swab tests and microbial count tests revealed that BiSCaO Water, ethanol, and hypochlorous acid exhibited cleaning and disinfection efficacy for various environmental surfaces, including those of wooden plates, clothes, metals, glass plates, rubber, and cowhide goods. Given that ethanol and hypochlorous acid have relatively high environmental load and adverse effects on human tissues, BiSCaO Water may be a superior disinfectant in terms of safety.

Prophylactic antimicrobial agents are administered to prevent surgical site infections (SSIs); guidelines recommend dosage and interval adjustment of prophylactic antimicrobial agents according to renal function to achieve adequate blood levels. Recently, it has been reported that the blood concentration of cefmetazole sodium (CMZ) is lower in patients with good renal function during lower gastrointestinal tract surgery, but there have been few reports on the relationship between renal function, CMZ dose, and the occurrence of SSI. We retrospectively investigated the relationship between SSI, CMZ dose used for prophylactic antimicrobial agents, and renal function in laparoscopic colon resections from January 2014 to August 2017. CMZ (1 g) was administered upon entry to the operating room and 3 h later. Patients who preoperatively used steroids, immunosuppressive agents, or antineoplastic agents, underwent hemodialysis, have BMI ≥ 25 kg/m², have intraoperative blood loss ≥ 1500 mL, and have surgery time <180 min were excluded. A total of 98 patients were included in the analysis, 93 in the non-SSI group and 5 in the SSI group. A significant difference was observed in the individualized body surface area estimated glomerular filtration rate (eGFRind) between the non-SSI group (66.31 mL/min) and the SSI group (80.95 mL/min) (P = 0.01). A eGFRind cutoff value of 70.68 mL/min was calculated via ROC curve analysis (AUC = 0.841, specificity 67.7%, sensitivity 100%). Our findings suggest that 1 g of CMZ administered 3 h after surgery may be insufficient; the dose should be increased, or the interval between intraoperative additional doses should be shortened in patients with an eGFRind I ≥ 70.68 mL/min.

In April 2020, we experienced a nosocomial outbreak of COVID-19. As a result of the outbreak, a total of 36 people were laboratory-confirmed to be infected, including 7 inpatients and 29 staff members. A total of 354 PCR tests were conducted on patients and staff, and 349 staff members were placed on self-monitoring at home. The following four routes of infection were estimated: 1) transmission from known infected patients to staff, 2) transmission from patients who have not yet been diagnosed with COVID-19 to staff, 3) transmission from staff who have been contracted with COVID-19 in 1) to patients, 4) transmission among staff, and 5) transmission from an environment contaminated with SARS-CoV-2 to staff. After the outbreak was confirmed, the area was red-zoned, and the following measures were taken: 1) red-zoning to reduce the number of donning and doffing of personal protective equipment, 2) mandating infected patients to use surgical masks all the time, and 3) universal masking of staff and patients in the hospital. The criteria for entering the critical care unit were also developed. As a result of these measures, the outbreak was successfully contained, and we were able to maintain cluster-free environment as of this writing.

Human mastadenovirus (HAdV) is highly resistant to common hand disinfectants. Epidemic keratoconjunctivitis and pharyngoconjunctival fever cause explosive infections in confined spaces, leading to nosocomial infections and other mass infections. Hemorrhagic cystitis and DIC caused by HAdV is also a major problem during hematopoietic stem cell transplantation, and since there are currently no effective antiviral agents against HAdV infection, it is important to control the spread of infection using disinfectants.

The disinfecting and virucidal abilities of ozone are already well known. In 2019, we reported that ozonated alcohol agent has high virucidal potential. Contrarily, alcohol disinfectant is not a disinfectant that can be used universally; there are cases in which it cannot be used due to religious beliefs. Therefore, in this study, we evaluated the antiviral activity of the agent with ozone stabilized in oil using adenovirus to evaluate its ability as a disinfectant. The viability of the virus was evaluated through reaction times ranging from 30 s to 5 min. As a result of this study, slight differences in reactivity were observed among HAdV types, but more than 70% of the virus was killed within 30 s, and the virus survival rate was reduced to 1/100 within 3 min. It was confirmed that the ozonated oil disinfectant is capable of killing HAdVs.

This study aimed to examine the oral environment of older adult home care patients who use visiting nursing services and to explore related factors. Direct observation of the participants' oral cavity was conducted using the Japanese version of the Oral Health Assessment Tool (OHAT-J) on patients at a visiting nursing station. The OHAT-J is an oral assessment tool for older adults and consists of eight items: "lips", "tongue", "gums and tissues", "saliva", "natural teeth", "dentures", "oral cleanliness", and "dental pain". The range of possible scores is 0-16, and the higher the score, the worse the oral environment. Path analysis using the OHAT-J total score as the final endogenous variable was employed to explore the factors related to the oral environment of the patients. Of the 129 older adult home care patients asked to complete the survey, 67 did so (51.9% acceptance rate). The mean OHAT-J total score was 4.2 (SD 2.6). Items such as "tongue" and "oral cleanliness" were evaluated as "oral changes" or "unhealthy" for most of the patients. The path analysis indicated that the item with the highest overall effect on the OHAT-J total score was "nursing care level 3 or higher" (β = 0.31). The oral environment of the patients in this study was poorer than that of older community-dwelling adults with access to outpatient dental services in previous studies. It is recommended that support be given to those who require a high level of nursing care, who are experiencing cognitive decline, and whose family are having difficulties in providing oral care for them.

A questionnaire survey was conducted among certified infection control nurses or certified nurse specialists in infection control in 629 institutions to investigate their perceived necessity of educating staff nurses on antimicrobial therapy, the current state of in-service nursing education on antimicrobial therapy at their institutions, and their activities in ASTs or ICTs. A total of 139 responses were obtained (response rate: 22.1%). The necessity of educating staff nurses was widely perceived with regard to items related to antimicrobial preparation, change upon mixing, and blood concentration measurement, including "timing for dissolving and mixing antimicrobial agents" and "reasons for dissolving and mixing antimicrobial agents immediately before administration." In-service education on blood concentration measurement and on the doses of time-dependent antimicrobial agents was widely implemented. With regard to the three assessment items, in-service education was implemented in 30% to 50% of the surveyed institutions, with 40% to 60% of the respondents indicating that such education was "necessary." At AST/ICT meetings, infection control nurses were found to actively provide information about patient conditions. The present findings confirm the importance of the role of infection control nurses in antimicrobial stewardship, especially in promoting practical education and information-sharing with regard to antimicrobial administration based on the PK-PD theory and patient assessment.