Evaluation of a New Norovirus Genogroups GI and GII Molecular Diagnostic Assay Using Clinical Specimens Collected from Acute Diarrheal Outbreaks.

Norovirus is a leading cause of acute gastroenteritis (AGE) in Taiwan. To improve diagnosis as part of laboratory surveillance, AGE surveillance was conducted using a new fluorescent probe hydrolysis-based insulated isothermal polymerase chain reaction (PCR) method, the POCKIT system, and the results were compared with those obtained from conventional methods. A total of 119 clinical stool samples from reported AGE outbreaks were collected for this study.

Norovirus Genogroup II Epidemics and the Potential Effect of Climate Change on Norovirus Transmission in Taiwan.

The activity of norovirus varies from season to season, and the effect of climate change on the incidence of norovirus outbreaks is a widely recognized yet poorly understood phenomenon. Investigation of the possible association between climatic factors and the incidence of norovirus is key to a better understanding of the epidemiology of norovirus and early prediction of norovirus outbreaks. In this study, clinical stool samples from acute gastroenteritis outbreaks were collected from January 2015 to June 2019 in Taiwan.

Global Trends in Norovirus Genotype Distribution among Children with Acute Gastroenteritis.

Noroviruses are a leading cause of acute gastroenteritis (AGE) among adults and children worldwide. NoroSurv is a global network for norovirus strain surveillance among children <5 years of age with AGE. Participants in 16 countries across 6 continents used standardized protocols for dual typing (genotype and polymerase type) and uploaded 1,325 dual-typed sequences to the NoroSurv web portal during 2016-2020.

Molecular Epidemiology of GI.3 Norovirus Outbreaks from Acute Gastroenteritis Surveillance System in Taiwan, 2015-2019.

Norovirus is the leading cause of food-borne disease outbreaks. We conducted this study to examine the incidence and molecular characteristics of norovirus genogroup I infections from acute gastroenteritis outbreaks in Taiwan. Between January 2015 and June 2019, 2121 acute gastroenteritis clusters were reported to Taiwan CDC, of which 351 (16.

Genetic Diversity and Phylogenetic Analysis of Human Bocavirus 2 in Pediatric Patients with Acute Gastroenteritis in Taiwan.

Human bocavirus (HBoV) is a causative agent of respiratory and gastrointestinal diseases worldwide. Four HBoV species (HBoV1-4) have been identified so far. Although a previous report has documented the HBoV association with acute gastroenteritis (AGE) in Taiwan, their epidemiology, genetic diversity, and phylogenetic relationships remain unclear.

Phylogeographic and genetic characterization of porcine circovirus type 2 in Taiwan from 2001-2017.

Porcine circovirus type 2 (PCV2) is an important pathogen that causes significant economic losses in the swine industry worldwide. Five major PCV2 genotypes have been identified, including PCV2a, PCV2b, PCV2c, PCV2d, and PCV2e. To investigate the prevalence and phylodynamics of the different PCV2 genotypes in Taiwan, 214 PCV2 ORF2 sequences from Taiwan and other countries were analyzed.

Phylodynamic and Genetic Diversity of Canine Parvovirus Type 2c in Taiwan.

Canine parvovirus type 2c (CPV-2c) emerged in 2000 and is known for causing a more severe disease than other CPV-2 variants in puppies. In 2015, the emerging CPV-2c variant was isolated in Taiwan and it subsequently became the predominant variant. To trace the evolution of Taiwanese CPV-2c, we compared complete VP2 genes of CPV-2c from Taiwan and sequences obtained from GenBank.

Surveillance of upper respiratory infections using a new multiplex PCR assay compared to conventional methods during the influenza season in Taiwan.

Objectives: To improve diagnosis as part of laboratory surveillance in Taiwan, influenza-like illness (ILI) surveillance was conducted using a new multiplex PCR assay (FilmArray) and the results compared to those of conventional methods The study was performed during the winter months.

Methods: Throat swabs from patients with an ILI presenting to physicians in sentinel practices were collected during the 2016-2017 influenza season.

Results: A total of 52 samples tested positive by FilmArray Respiratory Panel.

Spatial Temporal Dynamics and Molecular Evolution of Re-Emerging Rabies Virus in Taiwan.

Taiwan has been recognized by the World Organization for Animal Health as rabies-free since 1961. Surprisingly, rabies virus (RABV) was identified in a dead Formosan ferret badger in July 2013. Later, more infected ferret badgers were reported from different geographic regions of Taiwan.

Molecular epidemiological analysis of Saffold cardiovirus genotype 3 from upper respiratory infection patients in Taiwan.

Background: Saffold cardiovirus (SAFV) belongs to the Cardiovirus genus of Picornaviridae family, and may be a relevant new human pathogen; Thus far, eleven genotypes have been identified. The SAFV type 3 (SAFV-3) is thought to be the major genotype and is detected relatively frequently in children with acute gastroenteritis and respiratory illness. The epidemiology and pathogenicity of SAFV-3 remain unclear.

Challenges and Strategies of Laboratory Diagnosis for Newly Emerging Influenza Viruses in Taiwan: A Decade after SARS.

Since the first case of severe acute respiratory syndrome (SARS) in Taiwan was identified in March 2003, viral respiratory infections, in particular the influenza virus, have become a national public health concern. Taiwan would face a serious threat of public health problems if another SARS epidemic overlapped with a flu outbreak. After SARS, the Taiwan Centers for Disease Control accelerated and strengthened domestic research on influenza and expanded the exchange of information with international counterparts.

Molecular Epidemiology and Phylogenetic Analysis of Human Adenovirus Caused an Outbreak in Taiwan during 2011.

An outbreak of adenovirus has been surveyed in Taiwan in 2011. To better understand the evolution and epidemiology of adenovirus in Taiwan, full-length sequence of hexon and fiber coapsid protein was analyzed using series of phylogenetic and dynamic evolution tools. Six different serotypes were identified in this outbreak and the species B was predominant (HAdV-3, 71.

Molecular epidemiologic and clinical characteristics of influenza B-associated complications among hospitalized patients during an outbreak in Taiwan.

Objectives: To study the resurgence of influenza B/Yam in Taiwan and summarize clinical findings of influenza B-associated complications among hospitalized patients, in particular the link between clinical and molecular epidemiologic characteristics.

Methods: Clinical information and isolates were collected through the national surveillance system of the Taiwan Centers for Disease Control. Potential risk factors associated with severe illness were analyzed.

Exploring the molecular epidemiology and evolutionary dynamics of influenza A virus in Taiwan.

The evolution and population dynamics of human influenza in Taiwan is a microcosm of the viruses circulating worldwide, which has not yet been studied in detail. We collected 343 representative full genome sequences of human influenza A viruses isolated in Taiwan between 1979 and 2009. Phylogenetic and antigenic data analysis revealed that H1N1 and H3N2 viruses consistently co-circulated in Taiwan, although they were characterized by different temporal dynamics and degrees of genetic diversity.

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.

Phylodynamics and molecular evolution of influenza A virus nucleoprotein genes in Taiwan between 1979 and 2009.

Background: Many studies concentrate on variation in the hemagglutinin glycoprotein (HA) because of its significance in host immune response, the evolution of this virus is even more complex when other genome segments are considered. Recently, it was found that cytotoxic T lymphocytes (CTL) play an important role in immunity against influenza and most CTL epitopes of human influenza viruses were remarkably conserved. The NP gene has evolved independently in human and avian hosts after 1918 flu pandemic and it has been assigned a putative role as a determinant of host range.

Clinical and genetic analysis of Human Bocavirus in children with lower respiratory tract infection in Taiwan.

Background: Human Bocavirus (HBoV) is a likely etiologic agent of acute respiratory disease in children. The prevalence of this virus has been studied in several sites worldwide. We conducted the first clinical and molecular study of HBoV in Taiwan at the Centers for Diseases Control, Taiwan.

Rapid differentiation of influenza A virus subtypes and genetic screening for virus variants by high-resolution melting analysis.

We assessed the use of high-resolution melting (HRM) analysis for the rapid identification of influenza A virus subtypes and the detection of newly emerging virus variants. The viral matrix gene was amplified by LightCycler real-time reverse transcription-PCR (RT-PCR) in the presence of the LCGreen I fluorescent dye. Upon optimization of the assay conditions, all the major influenza A virus subtypes, including H1N1, H3N2, H5N1, H7N3, and H9N2, were amplifiable by this method and had a PCR product length of 179 bp.

Genetic and antigenic analysis of epidemic influenza viruses isolated during 2006-2007 season in Taiwan.

Influenza viruses are some of the most active pathogens in Taiwan. The monitoring influenza activity has been coordinated by the Centers for Diseases Control, Taiwan, and the surveillance is based on integrated clinical and virological surveillance components. Data from sentinel physician networks and other sources, mainly hospitals were collected.

Characterization of the epidemic influenza B viruses isolated during 2004-2005 season in Taiwan.

To characterize the antigenic and genetic relationships of influenza B viruses isolated during the 2004-2005 season, a total of 11,707 clinical respiratory samples were tested of which 1572 (13.5%) were positive for influenza (463 type A and 1109 type B influenza). Of the type B viruses, 348 isolates collected in different parts of Taiwan were further analyzed.

Nasopharyngeal shedding of severe acute respiratory syndrome-associated coronavirus is associated with genetic polymorphisms.

Background: A high initial or peak severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) load in nasopharyngeal specimens was shown to be associated with a high mortality rate. Because all infected individuals were devoid of preeexisting protective immunity against SARS-CoV, the biological basis for the variable virus burdens in different patients remains elusive.

Methods: The nationwide SARS database in Taiwan was analyzed, and genotyping of 281 single-nucleotide polymorphisms (SNPs) of 65 genes was performed for 94 patients with SARS, to identify SNPs for which distribution between patients with or without detectable nasopharyngeal shedding of SARS-CoV was biased.

Laboratory-based surveillance and molecular epidemiology of influenza virus in Taiwan.

A laboratory-based surveillance network of 11 clinical virological laboratories for influenza viruses was established in Taiwan under the coordination of the Center for Disease Control and Prevention (CDC), Taiwan. From October 2000 to March 2004, 3,244 influenza viruses were isolated, including 1,969 influenza A and 1,275 influenza B viruses. The influenza infections usually occurred frequently in winter in the northern hemisphere.

Detection of severe acute respiratory syndrome coronavirus RNA in plasma during the course of infection.

We examined severe acute respiratory syndrome-associated coronavirus (SARS-CoV) RNA in plasma of 32 patients (probable SARS cases) by a quantitative real-time reverse transcription-PCR assay and reported that the highest detection rate, 75%, was found between day 5 and day 7 of illness, followed by rates of 64, 50, and 38% found between day 8 and day 11, day 2 and day 4, and day 12 and day 16, respectively. Analysis of sequential SARS-CoV load in plasma from six cases revealed different patterns of viremia, with the peak between day 4 and day 8. Our findings of the high detection rate of SARS-CoV RNA in plasma before day 11, together with the relative convenience of collecting and handling plasma, suggest that plasma can be used for early diagnosis of SARS.