Epidemiological information regarding the periodic epidemics of influenza C virus in Japan (1996-2013) and the seroprevalence of antibodies to different antigenic groups.

Background: Although influenza C virus is widely distributed throughout the world, epidemiological information, based on long-term surveillance, has not yet been acquired.

Objectives: To clarify the epidemiological features of influenza C virus infection, and to examine whether the prevalence of the antibodies against the influenza C virus is associated with the epidemics.

Study Design: Between 1996 and 2013, 36,973 respiratory specimens were collected from two pediatric outpatient clinics in Yamagata, Japan.

Molecular epidemiology of Coxsackievirus A16 strains isolated from children in Yamagata, Japan between 1988 and 2011.

To clarify the longitudinal molecular epidemiology of coxsackievirus A16, phylogenetic analysis based on the VP1 region of 220 isolates in Yamagata, Japan was performed. The resultant phylogenetic tree indicates that the Yamagata isolates and reference strains can be readily genotyped into three genogroups, and 0, 12 and 208 isolates belonged to the first, second, and third genogroups, respectively. The first genogroup includes only the prototype strain, the second strains that had disappeared by the end of the 20th century and the third comprises those that have been circulating since then in local communities, such as Yamagata.

Detailed genetic analysis of hemagglutinin-neuraminidase glycoprotein gene in human parainfluenza virus type 1 isolates from patients with acute respiratory infection between 2002 and 2009 in Yamagata prefecture, Japan.

Background: Human parainfluenza virus type 1 (HPIV1) causes various acute respiratory infections (ARI). Hemagglutinin-neuraminidase (HN) glycoprotein of HPIV1 is a major antigen. However, the molecular epidemiology and genetic characteristics of such ARI are not exactly known.

Endemicity of human metapneumovirus subgenogroups A2 and B2 in Yamagata, Japan, between 2004 and 2009.

To clarify a longitudinal epidemiology,we isolated 280 hMPV strains from patients with acute respiratory infections in Yamagata, Japan, between 2004 and 2009.We observed that the high season for hMPV was from winter to spring (between January and May) and the low season was in the fall (around September and October). A further molecular analysis revealed that subgenogroup A2 (A2) strains were the most commonly isolated (151/280; 53.

Cross-antigenicity among EV71 strains from different genogroups isolated in Yamagata, Japan, between 1990 and 2007.

We isolated and identified six subgenogroups (B2, B4, B5, C1, C2, and C4) of enterovirus 71 (EV71) between 1990 and 2007 in Yamagata, Japan. We measured neutralizing antibody (NT Ab) titers against those subgenogroup strains and the BrCr reference strain for antigenic analysis. Serological analysis of 83 residents in Yamagata in 2004 showed that differences in the NT Ab titer of each individual against the different subgenogroups were mostly within 4-fold.

Stability of the seven hexon hypervariable region sequences of adenovirus types 1-6 isolated in Yamagata, Japan between 1988 and 2007.

Seven hexon hypervariable regions (HVRs) of adenoviruses (Ads) were identified by comparing the regions among different serotypes; however, no one has compared HVR sequences among the identical serotypes, except for adenovirus type 3 (Ad3). To examine a variability between the HVRs for each serotype, we compared the sequences of Ad1-6 isolates, respectively, isolated between 1988 and 2007 in Yamagata, Japan. We selected 23-43 isolates randomly and sequenced 894-987 bp regions.

Analysis of monthly isolation of respiratory viruses from children by cell culture using a microplate method: a two-year study from 2004 to 2005 in yamagata, Japan.

Although well over 200 viral agents have been implicated in acute respiratory infections (ARIs) among children, no system able to detect such a wide range of viruses has been established. Between January 2004 and December 2005, a modified microplate method, including HEF, HEp-2, Vero E6, MDCK, RD-18S, and GMK cell lines (HHVe6MRG plate), was adopted to isolate viruses. A total of 1,551 viruses were isolated, representing both outbreaks and sporadic cases, from 4,107 nasopharyngeal specimens, at monthly isolation rates of 22.

Extreme Tall Stature in a Japanese Boy with a 48,XXYY Karyotype.

We report an 18-yr-old Japanese boy with a 48,XXYY karyotype and extreme tall stature (194 cm). A GnRH test at 12.5 yr of age showed hypergonadotropism (LH, 4.

Outbreak of human metapneumovirus detected by use of the Vero E6 cell line in isolates collected in Yamagata, Japan, in 2004 and 2005.

A number of epidemiological studies have shown human metapneumovirus (hMPV) to be one of the most important viral agents associated with acute respiratory infections in humans. However, due to the difficulty in growing the virus, all epidemiological studies of hMPV infection have been performed on the basis of the molecular method. Thus, the development of a cell line suitable for the isolation of hMPV from clinical specimens is a crucial step for further research.

Prolonged norovirus shedding in infants

Background: Noroviruses (NV) are one of the leading causes of gastroenteritis in young children; however, the duration of NV shedding in young children is not well known.

Methods: Fecal specimens were collected from children with acute gastroenteritis at a pediatric clinic during the period from November to December 2002 and tested for NV by reverse transcription-polymerase chain reaction.

Results: Of 71 children infected with NV, 60 (84.

A slow spread of adenovirus type 7 infection after its re-emergence in Yamagata, Japan, in 1995.

We have continued the epidemiological study on adenovirus type 7 (Ad7), which re-emerged in 1995 in Yamagata, Japan. Between 1999 and 2004, we isolated only four strains from 10,778 throat swab specimens among children with acute respiratory infections. A serological survey of 303 specimens revealed the antibody-positive rate against Ad7 to be 0-7.

Clinical features of influenza C virus infection in children.

Background: Seroepidemiological studies have revealed that influenza C virus is widely distributed globally. However, because the isolation of this virus is difficult, there have been few reports on its clinical features.

Methods: Between December 1990 and November 2004, 84,946 respiratory-tract specimens were obtained from patients < or = 15 years old.

Genetic diversity of influenza B virus: the frequent reassortment and cocirculation of the genetically distinct reassortant viruses in a community.

To characterize the genetic diversity of influenza B viruses isolated during one influenza season, the antigenic and genetic relationships among 20 strains of influenza B virus isolated in February and March 2001 at one pediatric clinic in Yamagata City, Japan, were investigated. The HA gene and seven other gene segments were phylogenetically divided into three distinct sublineages (Harbin/7/94-, Tokyo/6/98-, and Shiga/T30/98-related lineage) of the Yamagata/16/88-like lineage. The NS genes of the viruses belonging to the Harbin/7/94-related lineage have additional three nucleotides at positions 439-447, and were phylogenetically distinguishable from those of the currently circulating Yamagata/16/88- and Victoria/2/87-like lineages, but were closely related to that of the Yamagata/16/88-like lineage isolated before 1994.

Re-emergence of echovirus type 13 infections in 2002 in Yamagata, Japan.

Objectives: To analyze the prevalence of echovirus type 13 (Echo13) in Yamagata, Japan.

Methods: Virus isolation was performed from 6514 clinical specimens using six cell lines between January 1999 and December 2002. We also carried out a seroepidemiological study against Echo13, using 234 serum samples collected in 2001.

A rare appearance of influenza A(H1N2) as a reassortant in a community such as Yamagata where A(H1N1) and A(H3N2) co-circulate.

To find a new influenza subtype A(H1N2), 383 isolates identified as H1 by hemagglutination inhibition test between the 1998-1999 and 2001-2002 seasons in Yamagata, Japan, were screened by reverse transcription polymerase chain reaction. As a result, 3 strains from the 1999-2000 season were identified as possibly being A(H1N2). Although several of their clones were found to be A(H1N2), A(H1N1) and A(H3N2), we could not confirm the origin of the A(H1N2) clones without the original specimens.

Longitudinal investigation of epidemiologic feature of adenovirus infections in acute respiratory illnesses among children in Yamagata, Japan (1986-1991).

Using human embryonic fibroblast (HEF) and HEp-2 cell cultures, adenoviruses were isolated from 989 (3.7%) out of 26,793 pediatric patients with ARI in Yamagata, Japan from January, 1986 to December, 1991. All isolates were identified as types 1 (Ad1)-6 and no other serotypes were identified.

Cocirculation of two distinct groups of influenza C virus in Yamagata City, Japan.

The antigenic and genetic relationships among 15 strains of influenza C virus isolated between August, 1988, and May, 1990, in Yamagata City, Japan, were investigated. Based on the results of antigenic analysis with monoclonal antibodies to the hemagglutinin-esterase (HE) glycoproteins and oligonucleotide mapping of total vRNA, the isolates were divided into two distinct groups closely related to either C/Yamagata/26/81 or C/Aichi/1/81. Antigenic differences between two groups could be detected clearly with heterogeneous antiviral sera.

Six-year longitudinal analysis of adenovirus type 3 genome types isolated in Yamagata, Japan.

Five hundred eighty-seven adenovirus type 3 (Ad3) isolates were established from children with acute respiratory infections (ARI) from 1986 to 1991, in Yamagata, Japan. Ad3 could be found in almost all the months during the 6 years when two epidemics occurred, in 1987 and 1989. A molecular epidemiological study was done on 346 of the 587 isolates, using restriction endonucleases; BamHI, HindIII, SmaI, and BgIII were used.

Community-acquired influenza C virus infection in children.

To clarify the epidemiologic and clinical features of community-acquired influenza C infection in children, we took specimens throughout the year from a larger number of patients with acute respiratory illnesses in a pediatric clinic in Yamagata, Japan. During a 2-year survey, 20 strains of influenza C virus were isolated from 13,426 specimens. These isolates were recovered throughout the year.

The herald waves of influenza virus infections detected in Sendai and Yamagata cities in 1985-1990.

The community surveillance of respiratory virus infections performed during 1985-1987 in Sendai and 1988-1990 in Yamagata has identified a total of five herald waves of influenza virus infections: A/H3N2 virus infections in 1985 and 1989, A/H1N1 virus infections in 1986 and 1988, and type B virus infections in 1989. To investigate the antigenic and genetic relationships between the herald wave and epidemic strains, influenza A/H1N1 viruses isolated during the 1986 and 1988 herald waves were compared with those isolated during the 1986-1987 and 1988-1989 epidemic seasons, respectively, utilizing hemagglutination inhibition tests with anti-hemagglutinin monoclonal antibodies and oligonucleotide mapping of total viral RNAs. The results showed that multiple variants differing in antigenic and genetic properties were cocirculating during the 1986 herald wave as well as during each of the two epidemics (only one strain was isolated in the 1988 herald wave).

[A clinical evaluation of cefdinir in pediatric infections].

Cefdinir (CFDN), a new oral cephalosporin, was administered to 10 patients with various infections and the following results were obtained. 1. Clinical responses in 10 patients (1 patient with rhinitis, 2 with sinusitis, 1 with pharyngitis, 1 with tonsillitis, 4 with scarlet fever and 1 with abscess) were excellent in 6 and good in 4 with an efficacy rate of 100%.

Human malignant melanoma cell line (HMV-II) for isolation of influenza C and parainfluenza viruses.

HMV-II, a human malignant melanoma cell line, was compared with other cell lines (MDCK, Vero, and LLC-MK2) and primary cultures of monkey kidney (PMK) cells for the isolation and quantification of influenza and parainfluenza viruses. HMV-II cells were superior to MDCK and LLC-MK2 cells in quantification of the influenza C virus and were used successfully in the isolation of the virus from clinical specimens. The HMV-II cell line was also more sensitive for isolating parainfluenza viruses from clinical specimens than were Vero and PMK cells; there was, however, no significant difference in the quantification of the viruses among these cultures.