Search

The composition of platinum group alloys in insoluble residue liquid waste produced during spent nuclear fuel reprocessing depends on the type of fuel and the degree of burn-up. Consequently, for disposal of this waste by its vitrification in borosilicate glass, robustness of the vitrification process is necessary. It is very important in this process whether the platinum group alloy contained in the undissolved residue remains as a metal or blends into the glass. In this paper, the local structure and chemical state of each type of atom in borosilicate glass have been analyzed by SEM-EDS and EXAFS to evaluate the behavior of platinum group alloys in the glass. The SEM-EDS results showed that molybdenum migrate into the glass phase easily, while ruthenium, rhodium, and palladium atoms tend to stay in the alloy phase. The EXAFS showed that molybdenum (VI), ruthenium (IV), and palladium (0) were present in the same chemical form regardless of compositional change, while rhodium (III or IV) varied depending on the composition of the alloy.

Abstract Background This study assessed the differences in daily virus reduction and the residual infectivity after the recommended home stay period in Japan in patients infected with influenza and treated with baloxavir (BA), laninamivir (LA), oseltamivir (OS), and zanamivir (ZA). Methods We conducted an observational study on children and adults at 13 outpatient clinics in 11 prefectures in Japan during seven influenza seasons from 2013/2014 to 2019/2020. Virus samples were collected twice from influenza rapid test-positive patients at the first and second visit 4–5 days after the start of treatment. The viral RNA shedding was quantified using quantitative RT-PCR. Neuraminidase (NA) and polymerase acidic (PA) variant viruses that reduce susceptibility to NA inhibitors and BA, respectively, were screened using RT-PCR and genetic sequencing. Daily estimated viral reduction was evaluated using univariate and multivariate analyses for the factors such as age, treatment, vaccination status, or the emergence of PA or NA variants. The potential infectivity of the viral RNA shedding at the second visit samples was determined using the Receiver Operator Curve based on the positivity of virus isolation. Results Among 518 patients, 465 (80.0%) and 116 (20.0%) were infected with influenza A (189 with BA, 58 with LA, 181 with OS, 37 with ZA) and influenza B (39 with BA, 10 with LA, 52 with OS, 15 with ZA). The emergence of 21 PA variants in influenza A was detected after BA treatment, but NA variants were not detected after NAIs treatment. Multiple linear regression analysis showed that the daily viral RNA shedding reduction in patients was slower in the two NAIs (OS and LA) than in BA, influenza B infection, aged 0–5 years, or the emergence of PA variants. The residual viral RNA shedding potentially infectious was detected in approximately 10–30% of the patients aged 6–18 years after five days of onset. Conclusions Viral clearance differed by age, type of influenza, choice of treatment, and susceptibility to BA. Additionally, the recommended homestay period in Japan seemed insufficient, but reduced viral spread to some extent since most school-age patients became non-infectious after 5 days of onset.

To evaluate the changes in respiratory syncytial virus (RSV) collected between 2019 and 2022, we analyzed RSV-A and RSV-B strains from various prefectures in Japan before and after the COVID-19 pandemic. RT-PCR-positive samples collected from children with rapid test positivity at outpatient clinics in 11 prefectures in Japan were sequenced for the ectodomain of the G gene to determine the genotype. Time-aware phylogeographic analyses were performed using the second hypervariable region (HVR) of the G gene from 2012 to 2022. Of 967 samples, 739 (76.4%) were found to be RSV-positive using RT-PCR. RSV peaked in September 2019 but was not detected in 2020, except in Okinawa. Nationwide epidemics occurred with peaks in July 2021 and 2022. The genotype remained the same, ON1 for RSV-A and BA9 for RSV-B during 2019–2022. Phylogeographic analysis of HVR revealed that at least seven clusters of RSV-A had circulated previously but decreased to two clusters after the pandemic, whereas RSV-B had a single monophyletic cluster over the 10 years. Both RSV-A and RSV-B were transferred from Okinawa into other prefectures after the pandemic. The RSV epidemic was suppressed due to pandemic restrictions; however, pre-pandemic genotypes spread nationwide after the pandemic.

Providing appropriate immunization information during the perinatal period is important for improving immunization rates among infants and children; however, the distribution of immunization information by healthcare workers (HCWs) is not standardized in Japan. We investigated HCWs’ attitudes toward childhood immunization and factors related to vaccine hesitancy. We conducted a cross-sectional descriptive survey of HCWs involved in childhood immunization in Niigata City, Japan, from November 2017 to January 2018. We assessed contextual, individual and group, and vaccine/vaccination-specific influences. Of 290 HCWs, 139 (47.9%) returned completed questionnaires. Most HCWs (87/139, 64.9%) reported providing immunization information verbally to parents; 51/87 (58.6%) spent fewer than five minutes doing so. Pediatricians provided vaccines based on the parents’ best interest, whereas public health nurses and midwives emphasized government policy. Nurses had greater hesitancy related to personal perceptions and social/peer factors than pediatricians (p < 0.001). Nurses were significantly more likely than pediatricians to suggest that children receive more shots than necessary (p < 0.01). Nurses tended to have more negative attitudes toward vaccination and little awareness of immunization promotion compared to pediatricians. Thus, all HCWs involved in childhood immunization should receive sufficient information to provide timely and appropriate immunization to infants and children.

This study examined the effects of providing vaccination education during the perinatal period on Japanese parents' knowledge, attitudes, and beliefs about childhood vaccination. A cluster-randomized controlled-trial method was used on a sample of 160 pregnant women recruited from 9 obstetrical sites in Niigata, Japan. The treatment group received a stepwise interactive education intervention, while the control group received a general vaccination leaflet. Changes in parental attitudes toward and beliefs about infant vaccination were assessed on the child's one-month and 6-month birthdays using paper questionnaires. Of the initial 188 participants, 160 (90.4%) completed the final post-survey questionnaire. Scores on injunctive social norms (a morally neutral perception of the behavior of the majority) and descriptive social norms (a moral perception of what individuals should do) significantly increased in the treatment group (p = .02 and p = .01, respectively). There was a significant difference between the 2 groups over time in terms of perceived benefit (efficacy of available preventive actions) (p = .03), but no significant differences in perceived severity (seriousness of a disease outcome), perceived susceptibility (likelihood of getting a disease), perceived benefits, perceived behavioral control, or descriptive social norms between the groups at any time point or in the patterns of change over time (p > .31). Thus, stepwise perinatal vaccination education was found to positively influence maternal attitudes and beliefs about infant vaccination. This study suggests the importance of vaccination education during the perinatal period.

Background: We estimated influenza vaccine effectiveness (VE) in 2015–2016 season against medically attended, laboratory-confirmed influenza, when quadrivalent inactivated vaccine (IIV4) was first introduced in Japan, using test-negative case-control design. Influenza A(H1N1)pdm09 cocirculated with B/Yamagata and B/Victoria during the study period in Japan. Method: We based our case definition on two laboratory tests, real-time reverse transcription polymerase chain reaction (RT PCR), and virus isolation and compared VEs based on these tests. In addition, VE was evaluated by rapid diagnostic test (RDT). Nasopharyngeal swabs were collected from outpatients who visited clinics with influenza-like illness (ILIs) in Hokkaido, Niigata, Gunma and Nagasaki prefectures. Results: Among 713 children and adults enrolled in this study, 578 were influenza positive by RT PCR including, 392 influenza A and 186 influenza B, while 135 were tested negative controls. The adjusted VE by RT PCR for all ages against any influenza was low protection of 36.0% (95% confidence interval [CI], 3.1% to 58.6%), for influenza A was 30.0% (95% CI: −10.0% to 55.5%), and influenza B was moderate 50.2% (95% CI: 13.3% to 71.4%). Adjusted VE for virus isolation for A(H1N1)pdm09 was 37.1% (95% CI: 1.7% to 59.7%), Yamagata lineage 51.3% (95% CI: 6.4% to 74.7%) and Victoria lineage 21.3% (95% CI: −50.0% to 58.9%). VE was highest and protective in 0–5 years old group against any influenza and influenza A and B/Yamagata, but the protective effect was not observed for other age groups and B/Victoria. RDT demonstrated concordant results with RT PCR and virus isolation. Sequencing of hemagglutinin gene showed that all A(H1N1)pdm09 belong to clade 6B including 31 strains (88.6%), which belong to clade 6B.1 possessing S162N mutations that may alter antigenicity and affect VE for A(H1N1)pdm09. Conclusions: IIV4 influenza vaccine during 2015–2016 was effective against A(H1N1)pdm09 and the two lineages of type B. Younger children was more protected than older children and adults by vaccination. Keywords: Influenza, Influenza vaccine, Vaccine effectiveness, Quadrivalent inactivated vaccine (IIV4), Test negative case-control design, Japan

Substantial increase in amantadine‐resistant influenza A (H3N2) was reported in Asia and North America in 2005. In this study the frequency and genetic characteristics of amantadine‐resistant influenza A, circulated in Japan in 2005–2006 season, were investigated. Isolates were tested by amantadine susceptibility test (TCID50/0.2 ml method), and sequencing of the M2 gene to identify mutations that confer resistance. Additionally, the hemagglutinin (HA) and neuraminidase (NA) genes of the viruses were examined. In total, 415 influenza A isolates from six prefectures were screened, and 231 (65.3%) of 354 influenza A (H3N2) were amantadine‐resistant, with a serine to asparagine (S31N) change in the M2 gene. However, none of 61 A (H1N1) isolates were resistant. In addition, genetic analyses of the HA gene showed all amantadine‐resistant viruses clustered in one (named clade N), possessing specific double mutations at 193, serine to phenylalanine (S193F), and at 225, asparatic acid to asparagine (D225N), and sensitive viruses belonged to another group (clade S). The clinical presentations at the clinical visit did not differ between patients shedding clade N virus and those shedding clade S virus. None of the patients had received previous treatment with amantadine. The results indicate an unusually high prevalence and wide circulation of the amantadine‐resistance influenza A (H3N2) in Japan in the 2005–2006 season. These strains had the characteristic double mutations in the HA, in addition to the M2 mutation responsive for resistance. Antiviral resistance monitoring should be intensified and maintained for rapid feedback into treatment strategies, and selection of alternative therapeutic agents. J. Med. Virol. 79:1569–1576, 2007. © Wiley‐Liss, Inc. [ABSTRACT FROM AUTHOR]

At present, three licensed antiviral influenza agents are available in Japan: amantadine, zanamivir, and oseltamivir. These antiviral agents can be used for controlling and preventing influenza, but they are not a substitute for vaccination. Amantadine is an antiviral drug with activity against influenza A viruses, but not influenza B viruses. Persons who have influenza A infection and who are treated with amantadine can shed sensitive viruses early in the course of treatment and later shed drug-resistant viruses, especially after 5–7 days of therapy. Such persons can benefit from therapy even when resistant viruses emerge. In screening for amantadine susceptibility, enzyme-linked immunoassays, plaque reduction assays, and TCID50/0.2?ml titration are employed. The molecular changes associated with resistance have been identified as single-nucleotide changes, leading to corresponding amino acid substitutions in one of four critical sites, amino acids 26, 27, 30, and 31, in the transmembrane region of the M2 protein. The polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis method is quite useful. Resistant viruses have been circulated in outbreak situations at nursing homes where amantadine was used not only for treating influenza virus infection but also for Parkinson's disease. Measures should be taken to reduce contact, as much as possible, between persons taking and those not taking antiviral drugs for treatment or chemoprophylaxis. [ABSTRACT FROM AUTHOR]