世界で問題となっている薬剤耐性菌については，我が国では，AMRアクションプランに基づいて，取組を進めた。その成果等を，役職を離れ，個人的な立場から振り返った。

AMRアクションプラン（2016-2020）では，畜産分野では適正使用・慎重使用を中心とした取組を行ってきた。成果指標については，3薬剤について薬剤耐性率の目標値を設定していたが，1薬剤のみ目標値を達成できなかった。薬剤耐性率は畜種別に異なる点から，畜種別にきめ細やかな取組が課題であった。また，国際的な動向から，抗菌剤の使用量の削減が着目されているが，我が国の畜産分野の動物用抗菌剤使用量は，2016年から2020年までの間，ほぼ横ばいだったことから，今後は使用量の削減の努力が求められると考えられた。

2022年に国連環境計画（UNEP）が，3者協定の薬剤耐性対策の連携体制に参画した。これにより，環境における薬剤耐性対策に取り組むことが表明された。今後の国際的な動向を注視するとともに，我が国でも家畜糞尿由来の抗菌剤や薬剤耐性菌の拡散を制御する手法の研究が進むことを期待しているところである。

本年4月にAMRアクションプラン（2023-2027）が決定され，畜産分野では，新たに抗菌剤の使用量の削減目標が設定された。また，環境分野についても新たな取組が盛り込まれた。

薬剤耐性対策への必要性を関係者が自分ごととして考え，取り組んでもらうためにも，行政は現場に即した取組を推進していく必要がある。

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.

抗菌薬に耐性を有する薬剤耐性菌の出現と蔓延の問題が，世界的に深刻な規模で進行している。薬剤耐性菌蔓延の拡大に伴う社会への影響は甚大なものになることが懸念されている。WHOは薬剤耐性菌に対する人─動物─環境による包括的な対策として，ワンヘルスによる取り組みを提唱するとともに各国に国家行動計画の策定を求めており，我が国においてもアクションプランが制定され対策が進んでいる。しかしながら，環境を対象とした薬剤耐性菌については不明なことも多く，病院等の医療機関に由来する排水を対象とした研究事例は，世界的にみても未だ知見が限られているのが現状である。薬剤耐性菌による環境汚染問題の実態を評価し，その蔓延抑制・低減に向けた取り組みを行うことは，持続可能な人類の繁栄と地球環境の保全を両立させる上でも重要な課題である。本稿では，近年明らかになりつつある医療機関に由来する排水と，下水処理場，河川を対象に，抗菌薬及び薬剤耐性菌の実態と環境リスク低減対策としての浄化処理についての知見をまとめ，今後の環境リスク評価・リスク管理の展望について概説する。

新型コロナウイルス感染症の重症化予防と感染拡大防止のために，5歳以上の全人口を対象としたワクチン接種が推奨されている。一方で，ワクチン接種による副反応の発生頻度は若者において高く，接種の躊躇につながっている。本研究では若者がワクチン接種を受ける際の判断材料となる情報を得るために，ワクチン接種後の大学生にアンケート調査をおこなった。

mRNA-1273接種を受けた北里大学獣医学部の学生1,099人を対象として調査票を配布し，231人（回収率：21.0%）から回答を得た。ワクチン接種前に前もって副反応に関する情報を得ていた人は220人（95.1%）であり，そのうちソーシャルネットワークサービス（SNS）から情報を得た人の割合は，男性よりも女性の方が有意に高かった（P<0.05）。ワクチン接種後の副反応出現率はすべての症状において1回目よりも2回目接種時に高く，2回目接種後では97.4%が何らかの症状を示していた。各症状の平均継続日数/症状の程度は，すべての症状において1回目よりも2回目接種時に長く/高くなった。2回目接種における各症状の継続日数・症状の程度を目的変数とした重回帰分析を実施したところ，各症状と性別，1回目接種時の症状，ペットの飼育，副反応に関する事前情報の有無に関連がみられた。また，2回目接種後に登校可能となった日数の調査では，接種後3日目で71.9%，4日目で89.6%に上昇していた。

本研究では日本の大学生におけるmRNA-1273接種による副反応の，出現率，継続日数，重症度，接種後登校可能になるまでの日数を明らかにした。

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.