Issues for antimicrobial resistance (AMR) have become a global problem. In Japan, we have been made efforts based on the AMR Action Plan. I left my position and looked back on the results from my personal standpoint.

In the AMR Action Plan 2016-2020, the livestock sector has focused on appropriate use and judicious use. Regarding outcome indicators, target values for the drug resistance rate were set for three drugs, but the target value could not be achieved for only one drug. Since drug-resistant rates vary by livestock species, it was necessary to make detailed efforts for each species. In addition, international trends have focused on reducing the amount of antibacterial agents used, but the amount of animal antibacterial agents used in the livestock sector in Japan remained almost unchanged during the period of the AMR Action Plan 2016-2020. Therefore, it was thought that efforts to reduce the amount used would be required in the future.

In 2022, the United Nations Environment Program (UNEP) will participate in the collaboration system for antimicrobial resistance measures of the tripartite agreement. With this, it was announced that efforts will be made to combat drug resistance in the environment. We are closely watching future international trends, and hope that research on methods to control the spread of antibacterial agents derived from livestock manure and drug-resistant bacteria will progress in Japan as well.

In April of this year, the AMR Action Plan 2023-2027 was published, and in the livestock sector, a new reduction target for the amount of antibacterial agents was set. New initiatives were also included in the environmental field.

Governments need to promote efforts that are appropriate to the actual situation, so that relevant parties can think of the necessity of antimicrobial resistance as their own matter and work on it.

Antimicrobial resistance (AMR) is a threat to global health, economic growth, and development. AMR in the livestock industry is one of the key issues because the large amounts of antimicrobials (AMs) are used to maintain animal health and productivity. Therefore, research and studies have been conducted in Japan, to develop various countermeasures against AMR in livestock sector.

Livestock manure is treated as waste or preferably used as fertilizer and/or ameliorant in agricultural fields. Nevertheless, in the “One Health” approach, such animal wastes are currently considered as an interface of AMs and antimicrobial resistant bacteria (ARB) between livestock industries and the environment. In contrast to European countries and China, research on AMs and ARB in livestock manure is meager in Japan.

Japanese swine farms have been used about 60% of total veterinary AMs sold and annually discharged about 22 million tons of manure (30% of total livestock waste). Swine manure in Japan is mainly treated under aerobic condition (wastewater treatment and composting), which is distinct to other countries, where mainly use an anaerobic condition. In addition, types and amounts of AMs and their usage patterns depend on each country. Such differences may affect the residual levels of AMs and ARB in manure-based end-products. In the light of the above, we are interested to understand the residue levels, fate and environment release of AMs and ARB in wastewater treatment and composting processes by conducting in situ monitoring in 11 Japanese swine farms and lab-scale experiments.

AM concentrations in untreated swine wastewater were from below method detection limits (<MDL; sub µg/L) to several mg/L and were found to be related to purchase quantities. The estimated removal rates of AMs were greater than 80%. In contrast, on a few occasions, it was diminished due to failing operating conditions, such as water temperature and activated sludge rate in the aeration tank. In addition to these two factors, aeration rates/times greatly affected the AM removal rates in lab-scale experiments. Likewise, some AMs could be removed well, if flocculation was done before the primary wastewater treatment process. The estimated ecological risks of AMs in effluents based on risk quotients considered to enhance the selection pressure for antimicrobial resistance were high for tetracyclines and fluoroquinolones, whereas ecotoxicological effects to aquatic organisms were relatively higher for sulfonamides and macrolides. The antimicrobial resistance rates in Escherichia coli isolated from wastewater did not change during treatment processes. However, total coliform counts were decreased noticeably, especially during the membrane separation method. These results indicate that flocculation before primary treatment and water-temperature controlled membrane bioreactor are effective methods of swine wastewater treatments for reducing the environmental release of AMs and ARB.

AMs in swine manure composts were detected at concentration ranging from <MDL (sub µg/kg on dry wt.) to 15 mg/kg. Unlike the case of wastewater, these concentrations were not related to purchase quantities of AMs but were affected by the removal efficiencies of AMs depending on composting methods. AM removal rates in open-type composting (pile-type and windrow-type) were high and constant, compared those in enclosed-type. Escherichia coli was not isolated from most of the swine manure composts, due to elimination during composting.

Since 2000, AMR studies associated with treatment of livestock manure and their effects after applying to agriculture fields are becoming new research topics and thus still there are lot of knowledge gaps. Our group is trying to bridge these gaps and suggest appropriate management of livestock manure.

Recently, the emergence and spread of antimicrobial-resistant bacteria (AMRB) have been progressing on a serious scale worldwide. The enormous impact on society due to the spread of antimicrobial-resistant bacteria is concerned. The World Health Organization (WHO) issued the Global Action Plan on Antimicrobial Resistance (AMR) as a comprehensive measure pertaining to medical care, livestock, and the environment (One Health) and formulated national action plans on AMR for each country. In Japan, the action plan for AMR has been implemented to contain the prevalence of AMRB. Nevertheless, research on the environmental fate of these pollutants remains limited and much remains unknown regarding the environmental impact of hospital wastewater. Evaluating the state of environmental pollution caused by antimicrobials (ARBs) and AMRB, and taking measures to control and/or reduce their discharge is an essential issue for supporting both sustainable human prosperity and the conservation of the global environment. This paper provides current research on the occurrence and fate of ARBs and AMRB in hospital wastewater, wastewater treatment plants, and rivers, and the development of advanced wastewater treatment systems as an environmental risk reduction measure. Finally, strategies for future human health risk assessment and risk management are discussed.

Vaccination of the entire population aged five years and older is recommended to prevent severe cases of coronavirus disease 2019 (COVID-19) and the spread of infection. However, the high frequency of adverse events from the vaccination of young people has led to a hesitation in vaccination. This study aimed to collect information on adverse reactions to vaccination among young people and to provide these results for vaccination decisions.

A questionnaire was distributed to 1,099 students of Kitasato University School of Veterinary Medicine who were vaccinated with the mRNA-1273 (Moderna) COVID-19 vaccine. The data were collected from 231 (21%) respondents. Among the respondents, 220 (95.1%) were able to obtain information on adverse reactions before vaccination. The proportion of people who obtained information from social network services was significantly higher for women than for men (P<0.05). The incidence of adverse events after vaccination was higher at the second vaccination than at the first for all symptoms, with 97.4% showing some symptoms after the second vaccination. The mean duration or severity of each symptom was longer or higher at the second vaccination than at the first for all symptoms. Multiple regression analysis was performed for the duration and severity of each symptom at the time of the second vaccination. The results showed an association between each symptom and factors such as sex, symptoms at the time of the first vaccination, whether or not respondents kept pets, and whether or not they were informed of adverse reactions to the vaccine. After the second vaccination, 71.9% of students reported being able to attend school on the third day, and 89.6% of students reported being able to attend school on the fourth day.

This study clarifies the incidence of adverse events, duration and severity of symptoms, and number of days before being able to attend school after vaccination with mRNA-1273 in Japanese university students.

In Japan, the Rabies Prevention Law was enforced in 1950, and the last reported case was 6 years later. The main reason for the success in eradicating rabies in a short period of time from a situation where rabies was prevalent was the eradication of stray dogs based on the Rabies Prevention Law and the strong promotion of vaccination. In the current situation where rabies does not exist, the current law plays a major role as a countermeasure against invasion from overseas and as a preparation for an outbreak. Rabies is a fatal disease, and unless rabies is eradicated from the world, rabies measures cannot be relaxed simply because the risk of outbreaks from overseas is very low. In order to minimize the damage even if it occurs in the future, we believe that it is important to maintain emergency and normal countermeasures that are in harmony with the impact of risk.

Interpretation of diagnostic test results requires epidemiological thinking. Diagnostic parameters such as diagnostic sensitivity and specificity can be influenced by various population-level factors such as the prevalence of the target disease, vaccination histories, and farm management practices as well as individual-level factors such as age and clinical signs. As the World Organisation for Animal Health (WOAH) specifies in its process for diagnostic validation, the fitness of purpose for specific diagnostic tests should be always evaluated in light of the epidemiology and characteristics of diseases in a given context. This series of contributions aims to cover basic terminologies for diagnostic test and principles of diagnostic test evaluation methods.

As controlling CSF infection in wild boars is the priority in CSF control and eradication in Japan, we visited Korea to investigate their political structure, strategy, and the result of ASF and CSF control in the country. For ASF control, the Ministry of Agriculture, Food and Rural Affairs oversee controlling the disease in farms, while the Ministry of Environment controls the disease among wild boars. Since ASFV is suspected to be the result of the spread of ASFV among wild boars from the northern part of the Korean Peninsula, intensive surveillance is being conducted to identify the infected area. In farms, strengthening the biosecurity measures such as placing double fences is becoming mandated by the government with its financial support. This information will be beneficial to review and enhance control measures against CSF in Japan.