Acute Disease ; epidemiology ; Adenovirus Infections, Human ; epidemiology ; virology ; Adenoviruses, Human ; genetics ; physiology ; Child, Preschool ; China ; epidemiology ; Feces ; virology ; Female ; Gastroenteritis ; epidemiology ; virology ; Genotype ; Humans ; Infant ; Infant, Newborn ; Male ; Prevalence ; Rotavirus ; genetics ; physiology ; Rotavirus Infections ; epidemiology ; virology

Objective: To understand the epidemiological and etiological characteristics of outbreaks on acute gastroenteritis caused by sapovirus (SaV) worldwide. Methods: Literature about the outbreaks on acute gastroenteritis caused by SaV were retrieved from the databases including WanFang, CNKI, PubMed and Web of Science after evaluation. Time, geography, setting and population distributions of outbreaks, transmission mode, SaV genotype and clinical characteristics of the patients were analyzed. Results: A total of 34 papers about SaV were included, involving 146 outbreaks occurred between October 1976 and April 2016. In these papers, 138 outbreaks were reported on the related months. All these outbreaks occurred in northern hemisphere. SaV outbreaks occurred all year around, but mainly in cold season, the incidence was highest in December (25 outbreaks) and lowest in in August (2 outbreaks). Most outbreaks were reported by Japan, followed by Canada, the United States of America and the Netherlands. There were 141 outbreaks for which the occurring settings were reported, child-care settings were most commonly reported setting (48/141, 34.04%), followed by long-term care facility (41/141, 29.08%) and hospital (16/141, 11.35%). Clinical symptoms of 1 704 cases in 31 outbreaks were reported, with the most common symptom was diarrhea (1 331/1 704, 78.12%), followed by nausea (829/1 198, 69.20%), abdominal pain (840/1 328, 63.25%), vomiting (824/1 704, 48.36%) and fever (529/1 531, 34.53%). Genotypes of SaV were determined for 119 outbreaks. GⅠ(51/119, 42.86%) and GⅣ (45/119, 37.82%) were predominant. The outbreaks of GⅣ SaV increased suddenly in 2007, and the outbreaks of GⅠ SaV mainly occurred in 2008 and during 2011-2013. Conclusions: SaV outbreaks were reported mainly by developed countries, with most outbreaks occurred in cold season, in child-care settings and long term care facility. GⅠ and GⅣ were the most common genotypes of SaV. Prevention and control of SaV outbreak in China seemed relatively weak, and it is necessary to conduct related training and to strengthen the SaV outbreak surveillance in areas where service is in need.
Caliciviridae Infections/virology* ; Child ; China/epidemiology* ; Disease Outbreaks ; Feces/virology* ; Gastroenteritis/virology* ; Genotype ; Humans ; Phylogeny ; RNA, Viral/genetics* ; Sapovirus/isolation & purification* ; Sequence Analysis, DNA

Objective: To understand the epidemiological and molecular characteristics of a norovirus- borne outbreak caused by GⅡ.4 Sydney 2012 in a university of Guangzhou to provide evidence for the prevention and control strategy on norovirus-caused epidemics. Methods: A self-designed questionnaire was used to collect clinical information from the patients as well as other data related to the epidemic. Pathogen detections were performed through anal swab specimens from the patients, kitchen workers and samples from the environment. Positive samples were further sequenced for phylogenetic analysis. A case-control study was employed to identify the risk factors related to this outbreak. Results: A total of 226 cases of norovirus-borne infection were identified between September 17 and 21, 2017, including 223 students, with an attack rate of 0.73% (223/30 711), and 3 kitchen workers. Students staying in the A dormitory area had the highest attack rate (1.73%, 164/9 459). No clustering was found in different colleges or classes. Results from the case-control study revealed that people who ate at the canteen in A dormitory area during September 18 to 20 was at risk for the onset of illness (OR=10.75, 95%CI: 5.56-20.79). The highest risk was related to the dinner on September 18. Another significant risk factor (OR=3.65, 95%CI: 1.92-6.94) was close personal contact in the same room of the dorm. The 3 norovirus infected kitchen workers were all from the canteen in A dormitory area where the positive rate of norovirus identified in kitchen workers was 26.67% (12/45). Positive samples were sequenced and sub-typed with results showing that the GⅡ.4 Sydney 2012 variant and the nucleotide sequences of cases and kitchen workers were 100% identical. Conclusions: The outbreak was caused by norovirus GⅡ.4 Sydney 2012 variant at campus. Similar outbreaks had been seen since 2013, with the routes of transmission most likely due to food-borne or personal contact.
Adolescent ; Adult ; Caliciviridae Infections/epidemiology* ; Case-Control Studies ; China/epidemiology* ; Disease Outbreaks ; Female ; Foodborne Diseases/virology* ; Gastroenteritis/virology* ; Humans ; Male ; Norovirus/isolation & purification* ; Phylogeny ; Surveys and Questionnaires

Norovirus (NoV) is a pathogen that commonly causes viral diarrhea in children. Studies indicate that NoV recognizes human histo-blood group antigens (HBGAs) as cell attachment factors. In order to explore the correlation between of NoV infection and HBGAs, a cross-sectional study was conducted in children less than five years old who were hospitalized with diarrhea in two areas of China between November 2014 and February 2015. Of the paired stool and saliva samples taken from 424 children, NoV was detected in 24 (6%) children, with viral genotypes GII.3 (n=5), GII.4 (n=14), GII.12 (n=1), and GII.17 (n=4). All of the individuals having NoV infection were either secretors (Lea-b+/Lex-y+) or partial secretors (Lea+b+/Lex+y+) except one GII.3 infection of a non-secretor (Lea+b-/Lex+y-). These results suggest that secretor positive is associated with NoV infection, although non-secretors are not absolutely protected from NoV infection.
Blood Group Antigens ; genetics ; Caliciviridae Infections ; blood ; complications ; virology ; Child, Preschool ; China ; Cross-Sectional Studies ; Diarrhea ; blood ; etiology ; virology ; Feces ; virology ; Gastroenteritis ; blood ; virology ; Genotype ; Humans ; Infant ; Norovirus ; physiology

INTRODUCTIONThis was the first study conducted to evaluate the efficacy of 2 oral doses of the human rotavirus vaccine, RIX4414 in Singaporean infants during the first 3 years of life.

MATERIALS AND METHODSHealthy infants, 11 to 17 weeks of age were enrolled in this randomised (1:1), double-blinded, placebo-controlled study to receive 2 oral doses of RIX4414 vaccine/placebo following a 0-, 1-month schedule. Vaccine efficacy against severe rotavirus (RV) gastroenteritis (Vesikari score ≥11) caused by wild-type RV strains from a period starting from 2 weeks post-Dose 2 until 2 and 3 years of age was calculated with 95% confidence interval (CI). Immunogenicity and safety of the vaccine were also assessed.

RESULTSOf 6542 infants enrolled, 6466 were included in the efficacy analysis and a subset of 100 infants was included in the immunogenicity analysis. Fewer severe RV gastroenteritis episodes were reported in the RIX4414 group when compared to placebo at both 2 and 3 year follow-up periods. Vaccine efficacy against severe RV gastroenteritis at the respective time points were 93.8% (95% CI, 59.9 to 99.9) and 95.2% (95% CI, 70.5 to 99.9). One to 2 months post-Dose 2 of RIX4414, 97.5% (95% CI, 86.8 to 99.9) of infants seroconverted for anti-RV IgA antibodies. The number of serious adverse events recorded from Dose 1 until 3 years of age was similar in both groups.

CONCLUSIONTwo oral doses of RIX4414 vaccine was immunogenic and provided high level of protection against severe RV gastroenteritis in Singaporean children, during the first 3 years of life when the disease burden is highest.

Antibodies, Viral ; immunology ; Double-Blind Method ; Female ; Gastroenteritis ; prevention & control ; virology ; Humans ; Immunogenicity, Vaccine ; Immunoglobulin A ; immunology ; Infant ; Male ; Rotavirus ; immunology ; Rotavirus Infections ; prevention & control ; Rotavirus Vaccines ; immunology ; therapeutic use ; Singapore ; Treatment Outcome ; Vaccines, Attenuated ; immunology ; therapeutic use

Rotavirus (RV) is one of the most important viral etiologic agents of acute gastroenteritis (AGE) in children. Although effective RV vaccines (RVVs) are now used worldwide, novel genotypes and outbreaks resulting from rare genotype combinations have emerged. This study documented RV genotypes in a Korean population of children with AGE 5 yr after the introduction of RVV and assessed potential genotype differences based on vaccination status or vaccine type. Children less than 5-yr-old diagnosed with AGE between October 2012 and September 2013 admitted to 9 medical institutions from 8 provinces in Korea were prospectively enrolled. Stool samples were tested for RV by enzyme immunoassay and genotyped by multiplex reverse-transcription polymerase chain reaction. In 346 patients, 114 (32.9%) were RV-positive. Among them, 87 (76.3%) patients were infected with RV alone. Eighty-six of 114 RV-positive stool samples were successfully genotyped, and their combinations of genotypes were G1P[8] (36, 41.9%), G2P[4] (12, 14.0%), and G3P[8] (6, 7.0%). RV was detected in 27.8% of patients in the vaccinated group and 39.8% in the unvaccinated group (P=0.035). Vaccination history was available for 67 of 86 cases with successfully genotyped RV-positive stool samples; RotaTeq (20, 29.9%), Rotarix (7, 10.4%), unvaccinated (40, 59.7%). The incidence of RV AGE is lower in the RV-vaccinated group compared to the unvaccinated group with no evidence of substitution with unusual genotype combinations.
Child, Preschool ; Feces/virology ; Gastroenteritis/immunology/prevention & control/virology ; Genotype ; Humans ; Infant ; *Mass Vaccination ; RNA, Viral/genetics ; Republic of Korea ; Reverse Transcriptase Polymerase Chain Reaction ; Rotavirus/*classification/*genetics/isolation & purification ; Rotavirus Infections/immunology/*prevention & control/virology ; Rotavirus Vaccines/*immunology ; Vaccines, Attenuated/immunology

Noroviruses are the leading cause of epidemic gastroenteritis, including foodborne outbreak, in Korea. The prevalence of human noroviruses was studied in diarrheal stool samples of patients with acute gastroenteritis by conventional duplex reverse transcription (RT)-PCR. Diarrheal stool samples were collected from 1,685 patients from the local hospitals in Seoul. The prevalence of the noroviruses was 22.8% (222/972 patients) in 2012 and 11.2% (80/713 patients) in 2013, with a total of 17.9% (302/1,685 patients). Genotyping was performed on 302 norovirus-positive stool samples to reveal 5.6% prevalence of genogroup I (GI) (17/302) and 94.4% prevalence of genogroup II (GII) (285/302). The patients with norovirus-associated acute gastroenteritis mostly showed prevalence of GII norovirus, especially GII.4 (64.6%; 195/302).
Acute Disease ; Feces/virology ; Gastroenteritis/*diagnosis/epidemiology/virology ; Genotype ; Humans ; Norovirus/*genetics/isolation & purification ; Prevalence ; RNA, Viral/genetics/metabolism ; Real-Time Polymerase Chain Reaction

Because of limited viral replication and lack of cytopathic effect in cell culture, a new PCR-based rapid seroneutralization assay for detection of GII.4 norovirus neutralized antibodies was developed with serum samples from acute-phase patients, convalescent-phase patients and healthy controls. According to this study, neutralizing antibodies were detected in 100% of convalescent-phase sera, and in 2.5% of healthy controls sera. However, all of the acute-phase serum samples could not neutralize virus efficiently. Compared to the results from ELISA (96.2% at sensitivity and 80% at specificity), the present in vitro neutralization assay is more specific and more sensitive.
Antibodies, Neutralizing ; immunology ; Base Sequence ; Caliciviridae Infections ; diagnosis ; virology ; Case-Control Studies ; Cell Line ; DNA Primers ; Enzyme-Linked Immunosorbent Assay ; Gastroenteritis ; diagnosis ; virology ; Humans ; Norovirus ; immunology ; isolation & purification ; Polymerase Chain Reaction ; methods ; Sensitivity and Specificity

Interactions between noroviruses (NoVs) and the receptors of histo-blood group antigens (HB-GAs) affect the infectivity and host susceptibility of NoVs. We elucidated the binding profile of a GII. 12 NoV to HBGAs. First, we synthesized the P domain sequence of the GII. 12 NoV strain Pune (GenBank accession number EU921353). Protein of the P domain was expressed in a prokaryotic system. Formation of the P particle was monitored by gel-filtration chromatography. Antiserum was prepared by immunization of mice with GII. 12 P particles. The binding profile of the GII. 12 NoV Pune strain was determined by binding of the P particle with a panel of saliva samples with various known HBGAs phenotypes. The GII. 12 NoV was bound strongly to saliva samples of subjects with B and AB types and weakly to A, O secretor, and non-secretor saliva samples, suggesting higher affinity with B antigen by GII. 12 NoV. These results were consistent with those determined by a previous crystallography study of GII. 12 NoV. These data suggested that individuals with B and AB blood types may be more susceptible to infection by GII. 12 NoV compared with those with other blood types. Our findings may provide a basis for the prevention and control of an epidemic of GII. 12 NoV.
Animals ; Blood Group Antigens ; metabolism ; Caliciviridae Infections ; metabolism ; virology ; Female ; Gastroenteritis ; metabolism ; virology ; Genotype ; Humans ; Mice ; Mice, Inbred BALB C ; Norovirus ; genetics ; metabolism ; Protein Binding ; Receptors, Virus ; metabolism ; Viral Proteins ; genetics ; metabolism

We studied the epidemiological characteristics of human bocavirus 4 (HBoV4) in children with a- cute gastroenteritis in Lanzhou (China). A total of 331 stool specimens were collected from children aged < 5 years with acute diarrhea at the First Hospital of Lanzhou University between July 2012 and June 2013. Specimens of HBoV were identified by nested polymerase chain reaction assays. Compared with related sequences in GenBank, the HBoV-positive strain isolated in the present study was,quite surprisingly, a rare genotype named HBoV4. This strain was a typical HBoV4,with high levels of nucleotide and amino acid homology to the Thailand strain, JQ267789 (98.9% and 98.7%, respectively), and the USA strain, GQ506568 (97.6% and 97.4%, respectively). This is the first report of HBoV4 as the causative agent for acute gastroenteritis in pediatric patients in China. This strain is one of two genotypes of HBoV that are currently circulating.
Child, Preschool ; China ; Feces ; virology ; Female ; Gastroenteritis ; virology ; Human bocavirus ; classification ; genetics ; isolation & purification ; Humans ; Infant ; Male ; Molecular Sequence Data ; Parvoviridae Infections ; virology ; Phylogeny