笹原 鉄平

An 88-year-old man was treated with high-dose systemic steroid therapy for COVID-19 and idiopathic interstitial pneumonia months before admission to the hospital because of swelling and redness in his left arm. Cryptococcus neoformans was detected in his blood sample on day eight of admission, and despite antifungal therapy, he died on day 43. Clinicians should be vigilant about the risk of prolonged immunosuppression as a side effect of high-dose systemic steroid usage for COVID-19.

We describe a case of probable prolonged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Alpha(B.1.1.7) variant shedding for 221 days from the diagnosis, in a healthy 20-year-old Japanese pregnant woman with a normal delivery. To our knowledge, this is the longest duration of SARS-CoV-2 shedding reported in an immunocompetent individual to date.

目的:近年途上国へ派遣される労働者が増加している。途上国は衛生環境が悪いことが多く、健康管理(感染症対策)が重要となる。赴任前に健康指導を受ける労働者、指導を行う産業医の認識を調査し、海外派遣労働者のニーズに合った、効果的な健康管理を提案することを目的とした。方法:途上国へ派遣された経験を持つ労働者を対象にインターネット調査を行い、属性、業種、滞在期間、勤務企業概要、赴任前推奨ワクチン種、ワクチン費用負担、感染症事前教育の有無・役立ち度・理解度、持参薬の有無、自社の感染症対策への満足度を収集した。また、指導する側として、産業医資格取得講習参加者を対象に、アンケートにて属性、日常業務における途上国赴任予定労働者からの相談の有無、日常業務における途上国赴任予定者に対する感染症に関する指導の有無、途上国赴任に際し推奨するアドバイス項目を取得した。結果:労働者が事前に得ることで、自社の感染症対策満足度に寄与する要因として、会社規模に加え、事前教育、相談窓口の情報提供が挙げられた。これらを多くの産業医資格取得講習参加者は、提供すべきと回答したが、情報提供に自信がないと考えていることが明らかとなった。結論:海外派遣労働者には、海外派遣前に、企業と連携し、事前教育、相談窓口の情報を、積極的に提供すべきである。また、産業医など指導する側は、渡航医学についての知識や情報源についての理解を深める必要がある。(著者抄録)

INTRODUCTION: Hand hygiene is crucial for infection control in long-term care facilities for elderly (LTCFEs), because it can be easily implemented in the low-resource settings of LTCFEs. This study investigated the actual status of hand hygiene adherence in LTCFEs, identified the factors inhibiting its appropriate implementation, and evaluated the effectiveness of a hand hygiene promotion program. METHODS: In this before-and-after study, participants were staff members (n = 142) at two LTCFEs in Gunma Prefecture, Japan. We modified the World Health Organization's "five moments for hand hygiene" and assessed participants' hand hygiene adherence rates in four situations: (1) Before touching around a resident's mucous membrane area; (2) Before medical practice or clean/aseptic procedures; (3) After body fluid exposure/risk or after touching around a resident's mucous membrane area; and (4) After touching a resident's contaminated environments. The study was divided into four phases. In Phase 1, participants self-assessed their hand hygiene adherence using a questionnaire. In Phase 2, we objectively assessed participants' pre-intervention adherence rates. In Phase 3, an intervention comprising various hand hygiene promotion measures, such as education and hands-on training on hand hygiene practices and timings, was implemented. In Phase 4, participants' post-intervention adherence rates were objectively measured. RESULTS: Although most participants reported high hand hygiene adherence rate in the self-assessment (93.1%), the pre-intervention evaluation revealed otherwise (16.8%). Participants' post-intervention adherence rates increased for all four situations (77.3%). CONCLUSION: The intervention program helped increase participants' hand hygiene adherence rates, indicating its effectiveness. Similar interventions in other LTCFEs may also improve adherence rates.

Following publication of the original article [1], the authors spotted errors in their paper concerning the positive rate in the right side in Table 2. (Table Presented).

Bacillus cereus is a spore-forming bacterium. B. cereus occasionally causes nosocomial infections, in which hand contamination with the spores plays an important role. Therefore, hand hygiene is the most important practice for controlling nosocomial B. cereus infections. This study aimed to determine the appropriate hand hygiene procedure for removing B. cereus spores. Thirty volunteers' hands were experimentally contaminated with B. cereus spores, after which they performed 6 different hand hygiene procedures. We compared the efficacy of the procedures in removing the spores from hands. The alcohol-based hand-rubbing procedures scarcely removed them. The soap washing procedures reduced the number of spores by more than 2 log(10). Extending the washing time increased the spore-removing efficacy of the washing procedures. There was no significant difference in efficacy between the use of plain soap and antiseptic soap. Handwashing with soap is appropriate for removing B. cereus spores from hands. Alcohol-based hand-rubbing is not effective.

自治医科大学附属病院では，鋭利物廃棄容器を携帯し忘れて発生する針刺し切創を防止するために，鋭利器材や廃棄容器などを搭載した独自の「血管穿刺支援カート」を企画し2010年に導入した．本研究では，2007–2013年における各年のカート配置総数・針刺し切創報告総件数・廃棄容器を携帯しないために発生した事例数を調査し，カート導入による針刺し切創の減少効果を評価した．針刺し切創報告総件数はカート導入前後で変化しなかったが，廃棄容器を携帯しないために発生した事例はカート導入によって有意に減少した(p<0.01)．また，カート配置総数と廃棄容器を携帯しないために発生した事例数の間には，負の相関が見られた（相関係数r=−0.83，p<0.05）．<br>

Background: Biological monitoring is used to assess toluene exposure in medical examinations. The American Conference of Industrial Hygienists, Japanese Society for Occupational Health and Deutsche Forschungsgemeinschaft have proposed various biological exposure determinants, such as toluene in blood and urine, and o-cresol in urine. Toluene in blood is a common biomarker among them. Toluene is a volatile organic solvent; therefore, sample preservation under appropriate conditions before measurement is necessary. However, little study has been done on the stability of toluene in workers' blood samples under conditions simulating those of a medical examination. Finding: We carried out a pilot study on the stability of toluene in blood from humans, according to different methods of sample preservation. Toluene in blood was analyzed by head space-gas chromatography/mass spectrometry. The sealing performance of the vial was examined by using toluene-added blood and the stability of toluene in blood according to the preservation period was examined by using blood from toluene-handling workers, which was collected with vacuum blood tubes. The sealing performance of the headspace vial used in this study was good for three days and toluene in blood in tubes from workers was stable at least within 8 hours up to blood packing at 4 degrees C. Conclusion: We could propose that the collected blood need only be transferred into headspace vials on the collection day and analyzed within a few days, if the samples are preserved at 4 degrees C. Our data size is limited; however, it may be considered basic information for biological monitoring in medical examinations.

Bacillus cereus (B. cereus) is a pathogen in opportunistic infections. Here we show that Bacillus cereus sphingomyelinase (Bc-SMase) is a virulence factor for septicemia. Clinical isolates produced large amounts of Bc-SMase, grew in vivo, and caused death among mice, but ATCC strains isolated from soil did not. A transformant of the ATCC strain carrying a recombinant plasmid containing the Bc-SMase gene grew in vivo, but that with the gene for E53A, which has little enzymatic activity, did not. Administration of an anti-Bc-SMase antibody and immunization against Bc-SMase prevented death caused by the clinical isolates, showing that Bc-SMase plays an important role in the diseases caused by B. cereus. Treatment of mouse macrophages with Bc-SMase resulted in a reduction in the generation of H2O2 and phagocytosis of macrophages induced by peptidoglycan (PGN), but no effect on the release of TNF-alpha and little release of LDH under our experimental conditions. Confocal laser microscopy showed that the treatment of mouse macrophages with Bc-SMase resulted in the formation of ceramide-rich domains. A photobleaching analysis suggested that the cells treated with Bc-SMase exhibited a reduction in membrane fluidity. The results suggest that Bc-SMase is essential for the hydrolysis of SM in membranes, leading to a reduction in phagocytosis.

We describe an outbreak of Bacillus cereus bacteremia that occurred at Jichi Medical University Hospital in 2006. This study aimed to identify the source of this outbreak and to implement appropriate control measures. We reviewed the charts of patients with blood cultures positive for B. cereus, and investigated B. cereus contamination within the hospital environment. Genetic relationships among B. cereus isolates were analyzed. Eleven patients developed B. cereus bacteremia between January and August 2006. The hospital linens and the washing machine were highly contaminated with B. cereus, which was also isolated from the intravenous fluid. All of the contaminated linens were autoclaved, the washing machine was cleaned with a detergent, and hand hygiene was promoted among the hospital staff. The number of patients per month that developed new B. cereus bacteremia rapidly decreased after implementing these measures. The source of this outbreak was B. cereus contamination of hospital linens, and B. cereus was transmitted from the linens to patients via catheter infection. Our findings demonstrated that bacterial contamination of hospital linens can cause nosocomial bacteremia. Thus, blood cultures that are positive for B. cereus should not be regarded as false positives in the clinical setting.

病院で使用するタオルには，加熱処理が義務づけられている．しかし，熱に耐性であるBacillus cereusの芽胞が病院タオルを汚染することがある．さらに，病院タオルのB. cereus汚染は医療関連感染の原因となりうる．したがって，病院タオルのB. cereus汚染を定期的に評価する必要がある．しかし，その評価のための標準方法は確立されていない．今回の研究において，我々は4つの測定方法(スタンプ法・スワブ法・単純抽出法・ビーズ抽出法)を用いて，病院タオルのB. cereus汚染の評価を行なった．スタンプ法ではタオル汚染を定量評価することが不可能であった．また，スワブ法では病院タオルから少数のB. cereusしか検出できなかった．一方，抽出法では病院タオルから多数のB. cereusを検出することができた．特に，ビーズ抽出法では単純抽出法の2倍の菌数を検出することができた．以上の結果より，ビーズ抽出法は病院タオルのB. cereus汚染の評価に最も適した測定方法と考えられる．さらに本研究の結果から，タオル中のB. cereusの分布密度が不均一であることが判明した．したがって，タオルのB. cereus汚染を評価する場合，1枚のタオルから複数のサンプル断片を採取して調べる必要がある．