In Vitro Characterization of Multidrug-Resistant Influenza A(H1N1)pdm09 Viruses Carrying a Dual Neuraminidase Mutation Isolated from Immunocompromised Patients.

Influenza A(H1N1)pdm09 viruses carrying a dual neuraminidase (NA) substitution were isolated from immunocompromised patients after administration of one or more NA inhibitors. These mutant viruses possessed an H275Y/I223R, H275Y/I223K, or H275Y/G147R substitution in their NA and showed enhanced cross-resistance to oseltamivir and peramivir and reduced susceptibility to zanamivir compared to single H275Y mutant viruses. Baloxavir could be a treatment option against the multidrug-resistant viruses because these dual H275Y mutant viruses showed susceptibility to this drug.

Epidemiological Aspects of Outbreaks in Japan and Genetic Characteristics of the Causative Pathogen.

Zoonotic pathogen has been identified as the cause of several human disease outbreaks; however, factors such as the general symptoms and incubation period of infection have yet to be defined. Therefore, we aimed to determine the unique aspects of outbreaks in Japan and to examine the genetic characteristics of the causative pathogen. We studied all known outbreaks that occurred in Japan up until 2015, which consisted of five confirmed outbreaks and one putative outbreak (Outbreaks 1-6).

Five-year Study of Viral Etiology and Features of Febrile Respiratory Tract Infections With Prolonged Fever in Japanese Pediatric Outpatients.

Over 5 years, we prospectively collected nasopharyngeal aspirate samples from pediatric outpatients with prolonged fever (≥5 days, ≥38.0°C). Real-time polymerase chain reaction assays identifying 13 different respiratory viruses and Mycoplasma pneumoniae were performed on the test samples.

Detection of gastroenteritis viruses among pediatric patients in Hiroshima Prefecture, Japan, between 2006 and 2013 using multiplex reverse transcription PCR-based assays involving fluorescent dye-labeled primers.

Multiplex reverse transcription (RT)-polymerase chain reaction (PCR)-based assays involving fluorescent dye-labeled primers were modified to detect 10 types of gastroenteritis viruses by adding two further assays to a previously developed assay. Then, these assays were applied to clinical samples, which were collected between January 2006 and December 2013. All 10 types of viruses were effectively detected in the multiplex RT-PCR-based assays.

Coronavirus Infections in Pediatric Outpatients with Febrile Respiratory Tract Infections in Hiroshima, Japan, over a 3-Year Period.

Previously, we conducted a 3-year prospective study to determine the viral causes of acute respiratory tract infections among 495 febrile pediatric outpatients. We collected 495 nasopharyngeal aspirate specimens, and used both real-time PCR assays and viral culture to test each for respiratory viruses other than coronavirus. Here, we used real-time PCR to test the 495 archival specimens for four human coronavirus strains.

Comparison of throat swab and nasopharyngeal aspirate specimens for rapid detection of adenovirus.

Nasopharyngeal aspirate (NPA) and throat swab (TS) specimens from individual patients were compared with regard to usefulness for adenovirus detection. In 153 adenovirus-infected patients, rapid test sensitivities with NPAs (90.8%) were nearly equivalent to those with TSs (91.

[Clinical, epidemiological, and etiological studies of aseptic meningitis in adults].

From summer to autumn, we noted the occurrence of a small epidemic of aseptic meningitis in adults. Over the last 10 years, we have encountered 203 male (mean age, 34.6 ± 15.

Three-year study of viral etiology and features of febrile respiratory tract infections in Japanese pediatric outpatients.

Background: For most febrile respiratory tract infections (RTIs) in children, the causative pathogen is never identified. We sought to identify the causative pathogen in individual cases of pediatric outpatient with RTIs and to determine whether particular clinical features of RTIs are associated with particular viruses.

Methods: Over 3 years, we prospectively collected nasopharyngeal aspirate specimens from individual pediatric outpatients with an RTI accompanied by persistent fever (>3 days, ≥38.

Use of two rapid influenza diagnostic tests, QuickNavi-Flu and QuickVue Influenza A+B, for rapid detection of pandemic influenza A (H1N1) 2009 viruses in Japanese pediatric outpatients over two consecutive seasons.

A prospective study of outpatient children conducted during 2 consecutive seasons (2009 and 2011) of pandemic influenza A (H1N1) 2009 virus determined the sensitivity of a chromatographic immunoassay test; real-time reverse transcription-polymerase chain reaction was the standard, and the test was 87.2% (117 patients in 2009) and 97.4% (114 patients in 2011) sensitive.

Influenza viral load and rapid influenza diagnostic tests in children and adults.

We compared children and adults with regard to rapid influenza test sensitivity and viral load. Specimen volumes were measured, rapid tests were conducted, and viral load was determined. There was no difference between children and adults in test sensitivity or viral load, but children had higher specimen volumes.

Evaluation of influenza virus A/H3N2 and B vaccines on the basis of cross-reactivity of postvaccination human serum antibodies against influenza viruses A/H3N2 and B isolated in MDCK cells and embryonated hen eggs.

The vaccine strains against influenza virus A/H3N2 for the 2010-2011 season and influenza virus B for the 2009-2010 and 2010-2011 seasons in Japan are a high-growth reassortant A/Victoria/210/2009 (X-187) strain and an egg-adapted B/Brisbane/60/2008 (Victoria lineage) strain, respectively. Hemagglutination inhibition (HI) tests with postinfection ferret antisera indicated that the antisera raised against the X-187 and egg-adapted B/Brisbane/60/2008 vaccine production strains poorly inhibited recent epidemic isolates of MDCK-grown A/H3N2 and B/Victoria lineage viruses, respectively. The low reactivity of the ferret antisera may be attributable to changes in the hemagglutinin (HA) protein of production strains during egg adaptation.

Catalytic and biochemical features of a monoclonal antibody heavy chain, JN1-2, raised against a synthetic peptide with a hemagglutinin molecule of influenza virus.

It has long been an important issue to produce a catalytic antibody that possesses the ability to lose the infectivity of a bacteria or virus. The monoclonal antibody JN1-2 was generated using a synthetic peptide (TGLRNGITNKVNSVIEKAA) conjugated with human IgG. The peptide sequence includes the conserved region of the hemagglutinin molecule (HA(1) and HA(2) domains), which locates on the envelope of the influenza virus and plays an important role in influenza A virus infection.

[Simultaneous multiple assay (Luminex xTAG respiratory viral panel FAST assay) efficacy in human respiratory virus detection].

Luminex xTAG respiratory viral panel FAST (RVP FAST) assay detects 17 human respiratory virus strains per measurement. Studying RVP FAST efficacy in detecting respiratory viruses in 67 aspirate samples from the nasal cavities of children with acute respiratory infection, we compared RVP FAST results to those of conventional nucleic acid amplification tests (NAT), e.g.

Rapid diagnosis of adenovirus respiratory tract infections using the chromatographic immunoassay test in the pediatric outpatient setting.

To assess the usefulness of a new rapid chromatographic immunoassay test for the detection of adenovirus, a prospective 3-year study was conducted in 587 febrile outpatient children suspected of adenovirus infection. A total of 332 children were diagnosed with this infection, using a viral culture. The sensitivity and specificity of the rapid test were 89.

Transition of genotypes associated with norovirus gastroenteritis outbreaks in a limited area of Japan, Hiroshima Prefecture, during eight epidemic seasons.

The transition of genotypes implicated in 102 NoV gastroenteritis outbreaks in Hiroshima Prefecture, Japan, during eight epidemic seasons was investigated. Eighteen genotypes were implicated in the outbreaks, with the chronological characteristics as in GII.3, GII.

Recombinant norovirus implicated in gastroenteritis outbreaks in Hiroshima Prefecture, Japan.

Norovirus (NoV) is a major etiological agent of acute gastroenteritis outbreaks worldwide. A total of 314 fecal specimens collected from patients of 39 NoV gastroenteritis outbreaks in Hiroshima Prefecture, Japan, between December 2001 and April 2006 were tested for the occurrence of recombinant NoVs. Sixteen genotypes (GI/1, GI/2, GI/4, GI/7, GI/8, GI/11, GI/14, GII/2, GII/3, GII/4, GII/5, GII/6, GII/8, GII/12, GII/14, and GII/untypeable) were detected in the 39 outbreaks based on capsid sequences and GII/4 was predominant recently.

A nationwide epidemic of influenza C virus infection in Japan in 2004.

During the period from January to July 2004, a total of 131 influenza C viruses were detected by cell culture or reverse transcription-PCR (RT-PCR) from specimens that were obtained from children with acute respiratory symptoms in 10 prefectures across Japan. Influenza C virus was identified most frequently in the Miyagi (1.4%, 45 of 3,226 specimens) and Yamagata (2.

[Evaluation of immunochromatography test for rapid detection of influenza A and B viruses using real-time PCR].

The sensitivity of rapid diagnostic kits to influenza B is lower than to influenza A. The cause-poor performance of the kit or the scarcity of viruses in type B specimens-has yet to be clarified. Using real-time PCR, we measured the amount of influenza viruses with nasopharyngeal aspirate fluid previously identified by virus isolation culture and passing the rapid diagnosis test by four types of kits, including the ESPLINE Influenza A&B-N (Fujirebio Corp.

Rapid detection of norovirus from fecal specimens by real-time reverse transcription-loop-mediated isothermal amplification assay.

In this study, we developed a one-step, single-tube genogroup-specific reverse transcription-loop-mediated isothermal amplification (RT-LAMP) assay for the detection of norovirus (NoV) genomes targeting from the C terminus of the RNA-dependent RNA polymerase gene to the capsid N-terminal/shell domain region. This is the first report on the development of an RT-LAMP assay for the detection of NoV genomes. Because of the diversity of NoV genotypes, we used 9 and 13 specially designed primers containing mixed bases for genogroup I (GI) and II (GII), respectively.