Bacteriological tests are reported in different ways over time: In the initial stage, only the smear test results are reported; the next day or later, the identification or intermediate test results are reported; and the next day or later, the final results, including drug susceptibility test results, are reported. Nevertheless, empirical antimicrobial therapy or transmission-based precautions may be necessary even before the final results are available, depending on the severity of the patient and the urgency of the disease.

In the initial stage, it will be discussed about the morphology of the microorganisms seen on the smear test, and how they can be reflected in the treatments and precautions. Next, in the mid-term stage, we will mention that the identification and susceptibility results can be determined to some extent based on the characteristics of the isolated colonies or the growth conditions in blood culture and explain that in some cases, the treatments and precautions should be changed. After explaining the final result of susceptibility testing, we will examine this testing process by adapting the example of healthcare-associated infections seen in intensive care units.

When many medical devices are utilized, determining ventilator-associated pneumonia, catheter-related bloodstream infection, catheter-associated urinary tract infection, and so forth is often difficult. This does not mean that all of them should be treated with antimicrobial agents. Some of them should be treated as offending bacteria, whereas others should not be treated as colonization. The question to consider is the likelihood of infection and the thresholds for treatment and testing. We will learn how to approach these issues by utilizing the flow of bacteriological tests.

Accurate knowledge is important for the implementation of effective infection control measures, and the same is true for emerging and re-emerging infectious diseases. Information on these infectious diseases is often lacking, and there are several uncertainties. Legionella infection is caused by all water-related facilities and equipment and is transmitted through the aerosol generation and inhalation of water during use; there is basically no human-to-human transmission. Standard precautions are sufficient, whereas especially, the removal or disinfection of contaminated water and water-related facilities and equipment is key intervention. In avian influenza, body fluids, feces, and respiratory tract secretions of infected birds or humans are the sources of infection, and migratory birds are a factor in spreading the virus around the world. Infection occurs through direct contact with the source of infection, slaughter/cutting, cooking, and so forth without personal protective equipment. Droplet and contact precautions to standard precautions are generally implemented. The Middle East respiratory syndrome is caused by direct contact with infected dromedary camels without personal protective equipment. Droplet and contact precautions to standard precautions are generally implemented. Although there is no conclusive evidence that avian influenza or MERS is transmitted via air, many specialists recommend the additional implementation of airborne precautions and negative pressure isolation because of their high fatality rates.

Promotion of the appropriate use of antimicrobial agents and infection control is important in managing antimicrobial resistance. Particularly, inappropriate use of antimicrobial agents is the greatest risk for bacterial resistance. Besides promoting antimicrobial stewardship programs within hospitals, a regional network with local hospitals, clinics, nursing homes, and health centers should be established. We have established a regional network through a two-tier structure, with the AMR Task Force as the administrative organization and the Control Team as the operational unit, in Shizuoka Prefecture. This paper describes the background, activities, effectiveness, and organizational structure during the COVID-19 pandemic. It is important to create an organization that deals with a wide range of infections, establish a secretariat, and interact with clinics on a daily basis.

After the corona disaster, the importance of proper use of disinfectants was reaffirmed in the medical field. Some disinfectants used in living organisms cannot be utilized, and some use concentrations differ depending on the indicated site. When treating living organisms, the use of a high concentration of disinfectant may cause a shock if the wound site or mucous membrane is diluted incorrectly and a high concentration of disinfectant is employed. It is necessary to always be aware of the effectiveness of disinfectants and the prevention of side effects. Cleaning is the basis of environmental maintenance at medical institutions, but disinfection is essential in the event of contamination. It must be understood that the method of disinfection of the equipment used for the patient is determined based on the degree of risk of infection at the site of the instrument. Adherence to hand sanitizer for healthcare workers remains one of the key issues for infection control in healthcare facilities. It is desirable to practice reliable hand disinfection at the necessary timing. In this paper, besides the basic knowledge necessary for practicing the proper use of disinfectants for living organisms, equipment and environment, and fingers, we have compiled a systematic understanding of disinfectants based on new knowledge.

[Background] The selection of alcohol-based hand sanitizers that cause minimal skin irritation is essential for the prevention of dryness and other skin problems in healthcare professionals. We used a three-dimensional (3D) skin model to perform skin irritation testing and to compare the results among seven alcohol-based hand sanitizers (class 3 OTC pharmaceuticals).

[Methods] The tests were conducted based on the OECD test guidelines (TG439). Cell viability was determined to be less than 50%, and IL-8 expression rates were determined to be irritating if they were a higher percentage than those of the negative controls. Ethanol concentrations were 78.89 vol% for reagent 1, 72 vol% for reagents 2 and 3, 76.9-81.4 vol% for reagents 4 and 5, and 83 vol% for reagents 6 and 7. Reagents 1-5 were ethanol-only, alcohol-based skin sanitizers, whereas reagents 6 and 7 were 0.2 w/v% chlorhexidine gluconate (CHG) -containing skin sanitizers containing alcohol. Reagents 1-3 had a pH range of 6.0-9.0, reagents 4 and 5 had a pH range of 2.6-4.0, and reagent 7 had a pH range of 5.5-7.0. The pH of reagent 6 was not disclosed.

[Results] The mean cell viability was 88%, 110%, and 79% for the ethanol-only formulations of reagents 1-3, and 68% and 61% for the two low-pH formulations of reagents 4 and 5.

The mean cell viability was 2.1% and 1.8% for the two formulations with 0.2 w/v% CHG, comprising reagents 6 and 7, and was determined, therefore, to be irritative.

Increased IL-8 expression was observed with both the low-pH formulations of reagents 4 and 5 (183% and 141%) and with reagent 6 (118%), one of the two 0.2 w/v% CHG-containing formulations.

[Conclusions] Skin irritation testing using a 3D skin model showed that ethanol-only, alcohol-based skin sanitizers were the least irritative to the skin.

The impact of the appropriate entry of the antimicrobial use notification form on the proportion of appropriate execution of the antimicrobial use process (process execution rate) is still unclear. In this study, we aimed to examine whether accurate and reliable entry of notification forms for antimicrobial use associate to improve the process execution rate.

In patients who received anti-MRSA or carbapenem antimicrobial agents from January 1 to December 31, 2018, at The University of Tokyo Hospital were included in this retrospective, observational study. Of the five items required to be entered in the notification forms for anti-MRSA and carbapenem antimicrobial agents use (dosage, expected duration of use, suspected site of infection, planned date of therapeutic drug monitoring [only for anti-MRSA agents], whether cultures of suspected infection site were collected [only for carbapenem antimicrobial agents], and whether blood cultures were collected), patients with ≥4 items entered were classified as the good-compliance group, whereas those with ≥3 items entered were in the poor-compliance group. The process execution rates by the attending physician for the five items were compared between the two groups.

A total of 399 patients were included: 145 in the anti-MRSA group (89 in the good-compliance group and 56 in the poor-compliance group) and 254 in the carbapenem antimicrobial agents group (178 in the good-compliance group and 76 in the poor-compliance group). No significant differences were observed in process execution rates between the good-compliance and poor-compliance groups in any of the five items for both the anti-MRSA agent group and the carbapenem antimicrobial agent group.

These observations suggest that, in facilities with the support of the Antimicrobial Stewardship Team, the impact of compliance with an entry on notification forms installed in an electric medical record system on the processes execution rates of appropriate antimicrobial use is limited and that there remains room for reconsideration of the items on the notification forms depending on the characteristics of the facility.

Background: Perioperative antimicrobial therapy is used for the prevention of surgical site infection (SSI) in lower gastrointestinal tract surgery. The US Centers for Disease Control and Prevention guidelines recommend administering antibiotics before and during the surgery; nevertheless, an additional dose of antibiotics is administered for 3-4 days after surgery in Japan. Our hospital has been working on the initiative for the cessation of postoperative antimicrobials in the lower gastrointestinal tract surgery since November 2018. We aimed to investigate whether this initiative was associated with the increased incidence rate of SSIs.

Methods: We retrospectively collected the data for the elective colorectal or rectal surgery performed between February 2014 and April 2021 and compared the incidence rate of SSIs before and after we started the initiative in November 2018 (before: group A [545 patients]; after: group B [295 patients]).

Results: Multivariable logistic regression analysis showed no significant increase in the incidence rate of SSIs in group B than in group A (adjusted odds ratio [OR], 1.09 [95% confidence interval: 0.73-1.63]). A sensitivity analysis was conducted using the same regression analysis that was performed for 541 patients in group A who continued postoperative antimicrobial therapy and 241 patients in group B who did not receive postoperative therapy, with an OR of 1.20 [0.78-1.78]. Interrupted time series analysis showed no change in the incidence rate of SSIs before and after November 2018 (trend change −1.32% [−2.82%-0.17%]). Postoperative hospital stay duration was significantly shorter in group B than in group A (17.4±13 and 14.8±9.7 days, respectively, P = 0.004).

Conclusions: The incidence rate of SSIs did not increase after starting the initiative, and the duration of hospital stay was reduced. Retrospective analysis using data from a single center provided useful evidence on appropriate antimicrobial use for preventing SSIs in the perioperative setting.

Since April 2018, the Antimicrobial Stewardship Team (AST) and full-time pharmacists have been assigned to the Nihon University Hospital. Particularly, we focused on daily monitoring of all antimicrobial agents for injection and blood culture results, de-escalation intervention, and appropriate use of antimicrobial agents in the perioperative period. We investigated these activities retrospectively over a 6-year period: 2 years before the intervention, 2 years in the initial period after the intervention (Phase I), and 2 years in collaboration with the pharmacist in charge of the hospital wards (Phase II). The number of antimicrobial therapy proposals decreased from 357 (adoption rate 86.8%) in Phase I to 167 (adoption rate 89.2%) in Phase II, due to the collaboration of ward pharmacists. Total antimicrobial consumption decreased in a stepwise fashion (median; 301.5 vs. 282.1 vs. 263.1, p < 0.001). We considered it to be an effect of the cephazolin intervention with low perioperative compliance. The de-escalation rate increased (pre; 73.3% vs. phase I; 90.3% vs. phase II; 89.8%, p < 0.001). This relationship was similar in patients with bacteremia (pre; 79.5% vs. stage I; 90.7% vs. stage II; 96.8%, p < 0.001). Conversely, there was no difference in 30-day mortality (pre; 8.4% vs. stage I; 5.2% vs. stage II; 3.9%, p = 0.180). The effect of the placement of a full-time pharmacist was to decrease the total antimicrobial consumption and increase the de-escalation rate. These results were maintained after collaboration with ward pharmacists.

Screening, surveillance, and early detection of coronavirus disease 2019 (COVID-19) cases are important components of outbreak management in healthcare facilities. At the beginning of the COVID-19 outbreak in March 2020, we set up an outpatient fever clinic aimed at streamlining screening testing for suspected patients arriving at the hospital to access routine healthcare services. Since then, identifying the appropriate screening strategy that is cost effective, robust, and effective has been an ongoing challenge. We initially screened all patients with any upper respiratory symptoms for COVID-19 regardless of their body temperature, which was an effective strategy considering that febrile status did not seem to impact the pretest probability at the start of the pandemic. This changed over time with fever being a significant predictor of a positive test result as different waves of COVID-19 variants hit throughout the country and the public's immunity status also changed. Our descriptive analysis and experience of screening 1,794 patients for COVID-19 at our fever clinic during the 2020-2021 pandemic demonstrate that healthcare facilities must adapt their screening strategy repeatedly over time in accordance with the evolving local context to run efficient screening programs with high sensitivity given the resource constraints.

We experienced an outbreak of vancomycin-resistant Enterococcusfaecium (VRE, Van A type) after the end of clostridium difficile infection (CDI) outbreak. We conducted a screening of ward staff and patients; three patients were detected with VRE. The infection control team evaluated the ward, and a few problems, such as the timing of hand hygiene and putting on and off of protector, were pointed out. We introduced continuous instruction and environmental maintenance. Thereafter, the number of enforcements per inpatient of hand disinfectants increased and the diaper exchange procedure observance rate was improved. The VRE outbreak was over within 1 month.

We conducted a workshop on the outbreak of CDI and VRE using this experience and planned reinforcement of infection measures inside the hospital.

In the future, the ward staff can continue environmental maintenance and hand hygiene.