Publications (27)71.68 Total impact
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Article: Detection of Five Rash-Associated Viruses Using Multiplex Real-Time PCR during 2006-2011.
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ABSTRACT: Many viruses have been reported to be associated with rash development. Multiplex real-time PCR was used to investigate the presence of 5 viruses associated with rashes: measles virus (MV), rubella virus (RV), human parvovirus B19 (PVB19), human herpes virus 6 (HHV-6), and HHV-7. A total of 187 clinical specimens from 169 patients with erythema were collected between January 2006 and December 2011. Virus-positive specimens were as follows: MV (n = 23), PVB19 (n = 8), RV (n = 2), HHV-6 (n = 5), HHV-7 (n = 1), MV and PVB19 (n = 1), and HHV-6 and HHV-7 (n = 1). All of the MV-positive specimens were collected in 2007 and the strains whose sequence were available (21/24, 87.5%) were of genotype D5. The results indicate that multiplex real-time PCR might be a useful screening method for detecting and differentiating rash-associated viruses in clinical specimens.Japanese journal of infectious diseases. 09/2012; 65(5):430-2. -
Article: Enterovirus 104 infection in adult, Japan, 2011.
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ABSTRACT: TO THE EDITOR: Human enterovirus (HEV) C (family Picornaviridae, genus Enterovirus) consists of 3 types of poliovirus (1, 2, and 3), 9 types of coxsackievirus A (CV-A1, 11, 13, 17, 19, 20, 21, 22, and 24), and 9 types of enterovirus (EV) (95, 96, 99, 102, 104, 105, 109, 113, and 116) (www.picornaviridae.com/enterovirus/hev-c/hev-c.htm). EV-104 was first identified in 2009 in Switzerland in 8 children who had pneumonia or acute otitis media (1). To our knowledge, there has been only 1 other report of EV-104, detected in Italy in 3 adults and 2 children who had upper respiratory tract infection (RTI) (2). We report the detection of a novel EV-104 strain in an adult with upper RTI in Japan.Emerging Infectious Diseases 05/2012; 18(5):882-3. · 6.79 Impact Factor -
Article: Increase of GII.2 norovirus infections during the 2009-2010 season in Osaka City, Japan.
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ABSTRACT: During the 2009-2010 season, a significant numerical increase of genotype GII.2 norovirus (NoV)-associated outbreaks was observed in Osaka City, Japan. The most common genotype in that season was GII.2 (44.6%), followed by GII.4 (39.2%). Mostly, GII.2 strains were associated with outbreaks in children and with person-to-person contact. The National Infectious Disease Surveillance Center reported that GII.2 NoV infections were widespread in Japan in that season. Comparative phylogenetic analysis of RNA-dependent RNA polymerase (RdRp) and capsid sequences revealed that this GII.2 epidemic resulted from two genetic strains. The first, GII.2p2 strains, had an identical genotype in the RdRp and capsid genes. GII.2p2 strains in the 2009-2010 season were a different genetic cluster from the strains of spring 2004, the previous epidemic of GII.2 NoV, but showed no unique amino acid change. The second, GII.2 chimera virus (GII.2p16), had GII.16 RdRp and GII.2 capsid genotypes, suggesting prior recombination at the junction of ORF1 and ORF2. GII.2p16 strains had four significant amino acid changes in the P2 subdomain, suggesting antigenic changes. Before the 2009-2010 season, GII.2 chimera viruses had been observed only sporadically. This spreading of GII.2p16 strains in the 2009-2010 season might be the first epidemic of GII.2 chimera virus. This study revealed that the NoV epidemic in the 2009-2010 season differed considerably from the prior season, when GII.4 was predominant. Furthermore, GII.2 strains persisted in human populations by drastic recombination and gradual accumulation of mutations, indicating a prevalent pattern of non-GII.4 genotypes with genetic evolution.Journal of Medical Virology 03/2012; 84(3):517-25. · 2.82 Impact Factor -
Article: Human sapovirus classification based on complete capsid nucleotide sequences.
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ABSTRACT: The genetically diverse sapoviruses (SaVs) are a significant cause of acute human gastroenteritis. Human SaV surveillance is becoming more critical, and a better understanding of the diversity and distribution of the viral genotypes is needed. In this study, we analyzed 106 complete human SaV capsid nucleotide sequences to provide a better understanding of their diversity. Based on those results, we propose a novel standardized classification scheme that meets the requirements of the International Calicivirus Scientific Committee. We believe the classification scheme and strains described here will be of value for the molecular characterization and classification of newly detected SaV genotypes and for comparing data worldwide.Archives of Virology 11/2011; 157(2):349-52. · 2.11 Impact Factor -
Article: High incidence of human echovirus type 3 among children in Osaka, Japan during the summer of 2010.
Japanese journal of infectious diseases. 11/2011; 64(6):533-5. -
Article: Molecular epidemiology of human rhinovirus C in patients with acute respiratory tract infections in Osaka City, Japan.
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ABSTRACT: Human rhinovirus (HRV) is a causative agent of acute respiratory tract infection (ARTI). In 2007, a novel HRV group, HRV-C, was discovered. This study, which assessed whether HRV-C is epidemic among patients with ARTI, was aimed at analyzing the seasonal prevalence of HRV-C in Osaka City, Japan. Gene amplification tests were performed to detect 10 respiratory viruses in 336 specimens collected during November 2008-October 2009. In total, 364 viruses were detected in 271 specimens. The most commonly detected virus was HRV (n = 84). For HRV-positive specimens, we conducted phylogenetic analyses using the VP4/VP2 gene region to identify the HRV species (HRV-C, 30; HRV-A, 54). Both the number and rate of HRV-C detection were highest in December. The highest numbers and the highest rate of HRV-A detection were obtained in April and June and in April, respectively. Statistical analysis showed that the most probable prevalent period of HRV-C was between September and March, and that of HRV-A was between March and November. These results suggest that HRV-C is mainly epidemic during autumn and early spring; this seasonal prevalence was different from that of HRV-A. Moreover, the HRV-C Osaka strains were scattered in many genetic clusters along with previously reported strains from different parts of the world. This result also emphasizes the worldwide circulation of HRV-C.Japanese journal of infectious diseases. 11/2011; 64(6):488-92. -
Article: Enterovirus 68 in children with acute respiratory tract infections, Osaka, Japan.
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ABSTRACT: Enterovirus 68 strains were detected in 14 specimens from children with respiratory tract infections and 1 specimen from a child with febrile convulsions during 2010 in Osaka, Japan. These strains had deletions in the 5' untranslated region and were genetically different from reported strains. This virus is associated with respiratory tract infections in Japan.Emerging Infectious Diseases 08/2011; 17(8):1494-7. · 6.79 Impact Factor -
Article: Molecular epidemiology of noroviruses detected in seasonal outbreaks of acute nonbacterial gastroenteritis in Osaka City, Japan, from 1996-1997 to 2008-2009.
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ABSTRACT: In seasons from 1996-1997 through 2008-2009, noroviruses (NoVs) were detected in 505 outbreaks (71%) of nonbacterial gastroenteritis in Osaka City, Japan using molecular diagnosis with reverse transcription (RT)-PCR or real-time RT-PCR. The occurrences of NoV-associated outbreaks were related with the cold season during November-March (85.3%), and occasionally small epidemics of NoVs occurring during April-June were observed. Oyster-associated outbreaks were dominant transmission modes (25-61.1%) before the 2003-2004 season, and decreased (5-20.5%) from the 2003-2004 season, although outbreaks attributable to food-borne transmission (except for oysters) and person-to-person contact increased from the 2003-2004 season. The NoV strains were characterized into genotypes based on sequence analysis of partial capsid regions. Genotyping analyses identified at least 30 genotypes (12 in genogroup I [GI] and 18 in genogroup II [GII]) of NoV. The most common genotype was GII.4 (44.6%), followed in order by GII.3, GII.6, GII.2, and GII.5. The number of GII.4 NoVs increased greatly from the 2003-2004 season, eventually comprising a large share among the NoV- associated outbreaks (97.4%) of the 2006-2007 season. Occasional increased prevalence of genotypes other than GII.4 was observed during this study period. This study showed the appearance, spread, and disappearance of various genotypes and the change of NoV epidemic in a limited geographic region. Continuous NoV molecular surveillance is important for understanding NoV infections and for improving measures for their control and prevention. J. Med. Virol. 82:2097-2105, 2010. © 2010 Wiley-Liss, Inc.Journal of Medical Virology 12/2010; 82(12):2097-105. · 2.82 Impact Factor -
Article: Detection and quantitative analysis of human bocavirus associated with respiratory tract infection in Osaka City, Japan.
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ABSTRACT: HBoV was initially identified in patients with RTI in 2005. Since its discovery, there have been continual reports concerning HBoV detection and its prevalence. In this study of clinical specimens from young children, real-time PCR was undertaken to examine whether HBoV infection is associated with RTI and to support quantitative analysis of HBoV in these patients. In all, 376 specimens were collected from patients with RTI during April 2006-October 2008. Analyses revealed HBoV in 59 specimens (15.7%). Of HBoV-positive patients, children under the age of 3 years comprised 94.9%. Of the HBoV-positive samples, 47.5% were codetected with other respiratory viruses (dual infection, 27; triple infection, 1). During the study period, the numbers and rate of detection of HBoV were high mainly around May. Statistical analyses showed that the detection rate of HBoV during April-June was higher than during other months. Moreover, the viral load was greater in subjects with infection with HBoV alone than in subjects with mixed respiratory viral infections. Considering these results together, HBoV is probably associated with RTI in young children. However, the pathogenesis of this infection and the importance of the high rate of co-infection remain uncertain. Additional epidemiologic information and further analyses are necessary to clarify the virological characteristics and the linkage of HBoV to disease.Microbiology and Immunology 05/2010; 54(5):276-81. · 1.30 Impact Factor -
Article: Norovirus illness is a global problem: emergence and spread of norovirus GII.4 variants, 2001-2007.
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ABSTRACT: Noroviruses (NoVs) are the most common cause of viral gastroenteritis. Their high incidence and importance in health care facilities result in a great impact on public health. Studies from around the world describing increasing prevalence have been difficult to compare because of differing nomenclatures for variants of the dominant genotype, GII.4. We studied the global patterns of GII.4 epidemiology in relation to its genetic diversity. Data from NoV outbreaks with dates of onset from January 2001 through March 2007 were collected from 15 institutions on 5 continents. Partial genome sequences (n=775) were collected, allowing phylogenetic comparison of data from different countries. The 15 institutions reported 3098 GII.4 outbreaks, 62% of all reported NoV outbreaks. Eight GII.4 variants were identified. Four had a global distribution--the 1996, 2002, 2004, and 2006b variants. The 2003Asia and 2006a variants caused epidemics, but they were geographically limited. Finally, the 2001 Japan and 2001 Henry variants were found across the world but at low frequencies. NoV epidemics resulted from the global spread of GII.4 strains that evolved under the influence of population immunity. Lineages show notable (and currently unexplained) differences in geographic prevalence. Establishing a global NoV network by which data on strains with the potential to cause pandemics can be rapidly exchanged may lead to improved prevention and intervention strategies.The Journal of Infectious Diseases 10/2009; 200(5):802-12. · 6.41 Impact Factor -
Article: Evaluation of real-time RT-PCR compared with conventional RT-PCR for detecting human metapneumovirus RNA from clinical specimens.
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ABSTRACT: Human metapneumovirus (hMPV) is an etiologic agent of respiratory tract infections. In this study, we compared the sensitivity and specificity of real-time reverse transcription (RT)-polymerase chain reaction (PCR), conventional RT-PCR, and nested PCR in detecting hMPV genes. A total of 146 clinical specimens from 143 patients who showed acute respiratory tract infection symptoms were tested by real-time RT-PCR, conventional RT-PCR, and nested PCR targeting for the fusion gene. We detected hMPV RNA from 14 (9.6%) clinical specimens (real-time RT-PCR, 8; conventional RT-PCR, 5; and nested PCR, 13). When conventional RT-PCR was the reference standard, the sensitivity and specificity of real-time RT-PCR were 100 and 97.9%, respectively. When nested PCR was the standard, the sensitivity and specificity of real-time RT-PCR were 53.8 and 99.2%, respectively. Therefore, real-time RT-PCR was more sensitive than conventional RT-PCR but less so than nested PCR. Phylogenetic analysis showed that the real-time RT-PCR detected four genetic sublineages of hMPV. These results taken together indicate that real-time RT-PCR is an efficient method for detecting four genetic sublineages of hMPV from clinical specimens.Japanese journal of infectious diseases 12/2008; 61(6):461-4. · 1.49 Impact Factor -
Article: Genetic analysis of the capsid gene of genotype GII.2 noroviruses.
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ABSTRACT: Noroviruses (NoVs) are considered to be a major cause of acute nonbacterial gastroenteritis in humans. The NoV genus is genetically diverse, and genotype GII.4 has been most commonly identified worldwide in recent years. In this study we analyzed the complete capsid gene of NoV strains belonging to the less prevalent genotype GII.2. We compared a total of 36 complete capsid sequences of GII.2 sequences obtained from the GenBank (n = 5) and from outbreaks or sporadic cases that occurred in The Netherlands (n = 10) and in Osaka City, Japan (n = 21), between 1976 and 2005. Alignment of all capsid sequences did not show fixation of amino acid substitutions over time as an indication for genetic drift. In contrast, when strains previously recognized as recombinants were excluded from the alignment, genetic drift was observed. Substitutions were found at five informative sites (two in the P1 subdomain and three in the P2 subdomain), segregating strains into five genetic groups (1994 to 1997, 1999 to 2000, 2001 to 2003, 2004, and 2005). Only one amino acid position changed consistently between each group (position 345). Homology modeling of the GII.2 capsid protein showed that the five amino acids were located on the surface of the capsid and close to each other at the interface of two monomers. The data suggest that these changes were induced by selective pressure, driving virus evolution. Remarkably, this was observed only for nonrecombinant genomes, suggesting differences in behavior with recombinant strains.Journal of Virology 09/2008; 82(15):7336-45. · 5.40 Impact Factor -
Article: Epidemic of genotype GII.2 noroviruses during spring 2004 in Osaka City, Japan.
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ABSTRACT: Between March and May 2004, a GII.2 genotype norovirus strain caused an epidemic of acute gastroenteritis in Osaka, Japan. Phylogenetic analysis showed that this strain was distinct from all other GII.2 strains detected in Osaka City between April 1996 and March 2005.Journal of clinical microbiology 08/2008; 46(7):2406-9. · 4.16 Impact Factor -
Article: Humoral immune responses against norovirus infections of children.
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ABSTRACT: In 2 infants with gastroenteritis associated with Norovirus (NoV), serum immunoglobulin (Ig) G, IgM, IgA, and fecal IgA antibody responses against NoV were examined by enzyme-linked immunosorbent assay using 11 different antigenic and genetic types of NoV virus-like particles expressed in insect cells. These two cases were putative primary single NoV infections, because antibodies against NoVs were not detected in acute-phase serums. In one of two cases, long-term excretion of virus RNA for 33 days was observed. Serum IgG responses demonstrated strong seroresponse to the homologous type, and weak seroresponse to the heterologous types within the genogroup. After more than 2 years, the IgG antibody titer remained high to the homologous type and low to the heterologous type within the genogroup. IgM and IgA were specific to the homologous type. IgM was short lived and the serum IgA antibody titer remained low to the homologous type for a long period. These results improve our understanding of the humoral immune response to NoV infection.Journal of Medical Virology 09/2007; 79(8):1187-93. · 2.82 Impact Factor -
Article: Co-infection of human metapneumovirus with adenovirus or respiratory syncytial virus among children in Japan.
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ABSTRACT: Human metapneumovirus (hMPV) is one of the etiological agents of acute respiratory tract infections. From June 2005 to May 2006, we collected 185 clinical specimens from children in Osaka City, Japan, and detected 41 hMPV RNA. Of the 41 specimens, four (9.8%) also contained other viruses (3 with adenovirus [AdV] and 1 with respiratory syncytial virus [RSV]). The clinical symptoms of patients coinfected with AdV were indistinct from those of patients mono-infected with hMPV. The symptoms of the one patient co-infected with RSV were clinically severe. Further research is needed to clarify the effect of hMPV on other respiratory viruses or vice versa.Microbiology and Immunology 02/2007; 51(7):679-83. · 1.30 Impact Factor -
Article: Seasonal distribution and phylogenetic analysis of human metapneumovirus among children in Osaka City, Japan.
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ABSTRACT: Human metapneumovirus (hMPV) is one of the etiological agents of respiratory tract infection (RTI). Because clinical symptoms of hMPV resemble those caused by respiratory syncytial virus (RSV), clinical diagnosis of hMPV infection is difficult. Moreover, hMPV isolation using cultured cells is generally difficult and not efficient compared with reverse transcription-PCR (RT-PCR). To assess infection and seasonal distribution of hMPV associated with RTI among children in Osaka City, Japan. To detect the hMPV gene, we extracted viral RNA from clinical specimens of patients with RTI and performed RT-PCR or nested-PCR for the fusion (F) gene. hMPV-specific amplicons were sequenced and subjected to phylogenetic analysis. From June 2004 to May 2005, we detected 29 (20.1%) hMPV strains among 144 clinical specimens. Fifteen strains were detected by RT-PCR and the remaining 14 by nested-PCR. Prevalence was principally in winter and spring with incidence peaking in April. We also detected the hMPV RNA from a patient with encephalitis. Approximately 80% of the hMPV-positive patients were younger than 3 years. To analyze these isolates precisely, a phylogenetic analysis using F gene was performed and demonstrated that Osaka City isolates of hMPV consists of two major genetic lineages each comprising two sublineages. We found two major genetic lineages of hMPV in Osaka City, Japan. We also found that nested-PCR was an efficient method for detecting the hMPV gene in clinical specimens. Of the 28 patients presenting with hMPV infection, 1 patient had associated encephalitis suggesting that hMPV infection might play a role in inducing encephalitis.Journal of Clinical Virology 05/2006; 35(4):394-9. · 3.97 Impact Factor -
Article: [Viral food-borne diseases caused by norovirus].
Journal of the Food Hygienic Society of Japan (Shokuhin Eiseigaku Zasshi) 01/2006; 46(6):235-45. · 0.43 Impact Factor -
Article: Probe typing of noroviruses detected in Osaka City, Japan.
Japanese journal of infectious diseases 03/2005; 58(1):53-4. · 1.49 Impact Factor -
Article: Genotyping of Norovirus strains detected in outbreaks between April 2002 and March 2003 in Osaka City, Japan.
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ABSTRACT: Noroviruses (NVs) are the major cause of food- and waterborne nonbacterial gastroenteritis in Japan. Between April 2002 and March 2003, a total of 111 fecal specimens from 40 outbreaks of acute nonbacterial gastroenteritis in Osaka City, Japan were subject to NV detection. Seventy-two samples (64.9%) from 31 outbreaks (77.5%) were NV positive by a real time reverse transcription (RT)-PCR assay. To further determine the genotype of individual NV strains, we sequenced the capsid N-terminal/shell (N/S) domain of some representative strains from each outbreak. The 51 NV strains detected in this study were segregated into 15 genotypes (6 in genogroup I and 9 in genogroup II), and GII/5 genotype NV was a dominant outbreak genotype.Microbiology and Immunology 02/2005; 49(3):275-83. · 1.30 Impact Factor -
Article: Isolation of Echovirus type 13 in Osaka City during 2001-2002.
Japanese journal of infectious diseases 07/2004; 57(3):127-8. · 1.49 Impact Factor
Top co-authors
Top Journals
Institutions
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2007–2012
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Osaka City General Hospital
Ōsaka-shi, Osaka-fu, Japan
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2008–2009
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RIVM
- Laboratory for Infectious Diseases and Perinatal Screening
Utrecht, Provincie Utrecht, Netherlands -
Osaka Prefecture University
Sakai, Osaka-fu, Japan
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2005
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Osaka City University
- Department of Virology
Ōsaka-shi, Osaka-fu, Japan
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