Genetic and antigenic characterisation of influenza A(H3N2) viruses isolated in Yokohama during the 2016/17 and 2017/18 influenza seasons.

BACKGROUND: Influenza A(H3N2) virus rapidly evolves to evade human immune responses, resulting in changes in the antigenicity of haemagglutinin (HA). Therefore, continuous genetic and antigenic analyses of A(H3N2) virus are necessary to detect antigenic mutants as quickly as possible. AIM: We attempted to phylogenetically and antigenically capture the epidemic trend of A(H3N2) virus infection in Yokohama, Japan during the 2016/17 and 2017/18 influenza seasons. METHODS: We determined the HA sequences of A(H3N2) viruses detected in Yokohama, Japan during the 2016/17 and 2017/18 influenza seasons to identify amino acid substitutions and the loss or gain of potential N-glycosylation sites in HA, both of which potentially affect the antigenicity of HA. We also examined the antigenicity of isolates using ferret antisera obtained from experimentally infected ferrets. RESULTS: Influenza A(H3N2) viruses belonging to six clades (clades 3C.2A1, 3C.2A1a, 3C.2A1b, 3C.2A2, 3C.2A3 and 3C.2A4) were detected during the 2016/17 influenza season, whereas viruses belonging to two clades (clades 3C.2A1b and 3C.2A2) dominated during the 2017/18 influenza season. The isolates in clades 3C.2A1a and 3C.2A3 lost one N-linked glycosylation site in HA relative to other clades. Antigenic analysis revealed antigenic differences among clades, especially clade 3C.2A2 and 3C.2A4 viruses, which showed distinct antigenic differences from each other and from other clades in the antigenic map. CONCLUSION: Multiple clades, some of which differed antigenically from others, co-circulated in Yokohama, Japan during the 2016/17 and 2017/18 influenza seasons

Dengue Type 3 Virus, Saint Martin, 2003–2004

We describe the spread of a dengue virus during an outbreak in Saint Martin island (French West Indies) during winter 2003–2004. Dengue type 3 viruses were isolated from 6 patients exhibiting clinical symptoms. This serotype had not been detected on the island during the preceding 3 years. Genome sequence determinations and analyses showed a common origin with dengue type 3 viruses isolated in Martinique 2 years earlier

Emergence and Global Spread of a Dengue Serotype 3, Subtype III Virus

Over the past two decades, dengue virus serotype 3 (DENV-3) has caused unexpected epidemics of dengue hemorrhagic fever (DHF) in Sri Lanka, East Africa, and Latin America. We used a phylogenetic approach to evaluate the roles of virus evolution and transport in the emergence of these outbreaks. Isolates from these geographically distant epidemics are closely related and belong to DENV-3, subtype III, which originated in the Indian subcontinent. The emergence of DHF in Sri Lanka in 1989 correlated with the appearance there of a new DENV-3, subtype III variant. This variant likely spread from the Indian subcontinent into Africa in the 1980s and from Africa into Latin America in the mid-1990s. DENV-3, subtype III isolates from mild and severe disease outbreaks formed genetically distinct groups, which suggests a role for viral genetics in DHF

Zidovudine plus lamivudine in Human T-Lymphotropic Virus type-I-associated myelopathy: a randomised trial

BACKGROUND: No therapies have been proven to persistently improve the outcome of HTLV-I-associated myelopathy. Clinical benefit has been reported with zidovudine and with lamivudine in observational studies. We therefore conducted a randomised, double blind, placebo controlled study of six months combination therapy with these nucleoside analogues in sixteen patients. RESULTS: Primary outcomes were change in HTLV-I proviral load in PBMCs and clinical measures. Secondary endpoints were changes in T-cell subsets and markers of activation and proliferation. Six patients discontinued zidovudine. No significant changes in pain, bladder function, disability score, gait, proviral load or markers of T-cell activation or proliferation were seen between the two arms. Active therapy was associated with an unexplained decrease in CD8 and non-T lymphocyte counts. CONCLUSION: Failure to detect clinical improvement may have been due irreversible nerve damage in these patients with a long clinical history and future studies should target patients presenting earlier. The lack of virological effect but may reflect a lack of activity of these nucleoside analogues against HTLV-I RT in vivo, inadequate intracellular concentrations of the active moiety or the contribution of new cell infection to maintaining proviral load at this stage of infection may be relatively small masking the effects of RT inhibition

DESIGN OF SNOW-CAR FOR JAPANESE ANTARCTIC RESEARCH EXPEDITION

This snow car is designed for the travel through the Antarctic inland. The main requirements for the design are as follows : 1. Performance of the engine at high altitudes must be improved so that the car can climb up to 4,000 m. 2. Durability of components and parts at extremely low temperatures (about-60℃) must be ensured. 3. The tractive force of the car must be strong enough to two sleds which weigh more than 6 tons. 4. The cabin must be of the cabover type and perfectly protected from blizzards. Since the car must be designed and constructed within a year, we decided to improve the Type 61 Snow Car currently in use by the Japan Ground Self Defence Force, so as to satisfy the above requirements. Before designing, we have studied and tested the performances of engine and turbochargers, selection of materials, durability of track plates and suspension springs and other parts. The car has about 8.5 tons gross weight, 0.20 kg/cm^2 ground contact pressure and accommodates a crew of 3 men. The body is of a cabover type, and the cabin is equipped with heating apparatus, ventilators, beds, cooking apparatus and others. The observation instruments and communication equipments also can be installed in it. The car has a 140 PS diesel engine and can cruise at a speed of about 5 km/h when towing 3 sleds weighing totally about 8 tons. The construction of the car will be completed at the end of January 1965, and then, the car will be tested in Hokkaido

Norovirus genotype distribution in outbreaks of acute gastroenteritis among children and older people: an 8-year study

Abstract Background Noroviruses (NoVs) are the most frequent cause of acute gastroenteritis worldwide among people of all ages and the leading cause of gastrointestinal disease outbreaks in various settings. To clarify the differences in epidemic situations among different settings, we investigated epidemiological trends and the distribution of NoV genotypes in Yokohama, Japan. Methods Between September 2007 and August 2015, 746 outbreaks of NoV gastroenteritis were reported in kindergarten/nursery schools (K/Ns), primary schools (PSs), and nursing homes for the aged (NHs). Stool samples were collected for NoV testing, and the NoV gene was amplified and sequenced to determine the genotype. Results During the eight seasons, 248 NoV outbreaks occurred in K/Ns, 274 outbreaks in PSs, and 224 outbreaks in NHs. These outbreaks occurred throughout the year, except in August, and the number increased in November and peaked in December. The number of outbreaks that occurred from November to February comprised 76.8 % of all outbreaks. The outbreaks originated in K/Ns or PSs in every season, except for one season. Five genogroup (G)I and nine GII genotypes in K/Ns, six GI and 10 GII genotypes in PSs, and three GI and six GII genotypes in NHs were detected during the eight seasons. GII.4 was the most prevalent genotype in K/Ns and NHs. However, GII.6 was the most prevalent genotype in PSs. The epidemic genotypes in K/Ns and PSs changed by NoV season, although GII.4 was always predominant in NHs. Moreover, the distribution of genotypes was significantly different between epidemic and non-epidemic periods in each facility (p < 0.01 for all). Conclusions The epidemic situation of NoV outbreaks differs by facility, NoV season, and month. The genotype distribution is likely dependent on the facility and is significantly different between epidemic and non-epidemic periods

ナンキョク カンソク ヨウ セツジョウシャ KD60 ノ キホン セッケイ ニツイテ

本南極観測用雪上車は,南極内陸調査旅行に使用する目的で設計されたものであり,短期間に試作を完了する必要があるため,現在陸上自衛隊に装備されている61式大型雪上車を母体とし,これに必要な改修を加えたものである.全備重量約8.5t,接地圧0.20kg/cm^2,乗員数3名,車体はキャブオーバー型で,車室内に暖房装置,換気装置,寝台,炊事用具等をそなえ,また,観測に必要な機器を塔載できるようになっている.エンジンは標準状態で140PSで,3台のそり約8tをけん引する場合の常用速度は約5km/hである.設計にあたって最も配慮したものは,-60℃に及ぶ低温下,低地から4,000mに至る高地で使用可能なこと,走行距離約6,000km,旅行期間5ヵ月の連続使用に耐えうること等の苛酷な条件についての対策である.このため,機関過給機,車両使用材料等の選定,カタピラおよび懸架バネ等の耐久性,車体等の保温,暖房その他については,事情の許すかぎり試験研究を行ない,これらの資料および前回の観測時の実績等を基礎として,基本設計を行なった.なお,本雪上車は1965年1月末試作を終え,北海道において試験を行なう予定である.This snow car is designed for the travel through the Antarctic inland. The main requirements for the design are as follows : 1. Performance of the engine at high altitudes must be improved so that the car can climb up to 4,000 m. 2. Durability of components and parts at extremely low temperatures (about-60℃) must be ensured. 3. The tractive force of the car must be strong enough to two sleds which weigh more than 6 tons. 4. The cabin must be of the cabover type and perfectly protected from blizzards. Since the car must be designed and constructed within a year, we decided to improve the Type 61 Snow Car currently in use by the Japan Ground Self Defence Force, so as to satisfy the above requirements. Before designing, we have studied and tested the performances of engine and turbochargers, selection of materials, durability of track plates and suspension springs and other parts. The car has about 8.5 tons gross weight, 0.20 kg/cm^2 ground contact pressure and accommodates a crew of 3 men. The body is of a cabover type, and the cabin is equipped with heating apparatus, ventilators, beds, cooking apparatus and others. The observation instruments and communication equipments also can be installed in it. The car has a 140 PS diesel engine and can cruise at a speed of about 5 km/h when towing 3 sleds weighing totally about 8 tons. The construction of the car will be completed at the end of January 1965, and then, the car will be tested in Hokkaido

Genetic Analysis of Norovirus GII.4 Variant Strains Detected in Outbreaks of Gastroenteritis in Yokohama, Japan, from the 2006-2007 to the 2013-2014 Seasons.

Noroviruses (NoVs) are the leading cause of acute gastroenteritis, both in sporadic cases and outbreaks. Since the 1990s, the emergence of several GII.4 variants has been reported worldwide. To investigate the epidemic status of NoV, 6,724 stool samples collected from outbreaks in Yokohama, Japan, from the 2006-2007 to 2013-2014 seasons were assessed for NoVs. We genotyped one specimen from each GII outbreak and conducted a sequence analysis of the VP1 gene for several GII.4 strains. Of the 947 NoV outbreaks during our study, GII was detected in 835, and GII.4 was the predominant genotype of GII. Five different GII.4 variants, Yerseke 2006a, Den Haag 2006b (2006b), Apeldoorn 2007, New Orleans 2009, and Sydney 2012, were detected. During this study period, the most prevalent variant of GII.4 was 2006b, and in each individual season, either 2006b or Sydney 2012 was the predominant variant. Out of the 16 detected 2006b strains, 12 had some amino acid substitutions in their blockade epitope, and these substitutions were concentrated in three residues. Two of the 2006b strains detected in the 2012-2013 season had a S368E substitution, which is consistent with the amino acid residues at same site of NSW0514 (Sydney 2012 prototype). Among the 16 detected strains of Sydney 2012, a phylogenetic analysis showed that all five strains detected in Yokohama during the 2011-2012 season clustered away from the other Sydney 2012 strains that were detected in the 2012-2013 and 2013-2014 seasons. These five strains and other Sydney 2012 strains in Yokohama had a few amino acid differences in the blockade epitopes compared with NSW0514. The amino acid substitutions observed in this study provide informative data about the evolution of a novel GII.4 variant