Caliciviridae Infections ; epidemiology ; China ; epidemiology ; Diarrhea ; epidemiology ; virology ; Humans ; Norovirus ; Rotavirus ; Rotavirus Infections ; epidemiology

Caliciviridae Infections ; epidemiology ; China ; epidemiology ; Disease Outbreaks ; Female ; Humans ; Male ; Norovirus ; Schools

Caliciviridae Infections ; prevention & control ; therapy ; Disease Outbreaks ; prevention & control ; Humans ; Norovirus ; Practice Guidelines as Topic

Caliciviridae Infections ; epidemiology ; virology ; Gastroenteritis ; virology ; Genetic Variation ; Genotype ; Humans ; Norovirus ; classification ; genetics

OBJECTIVE: To clarify the epidemiological characteristics and spatial distribution patterns of human norovirus outbreaks in China, identify high-risk areas, and provide guidance for epidemic prevention and control. METHODS: This study analyzed 964 human norovirus outbreaks involving 50,548 cases in 26 provinces reported from 2012 to 2018. Epidemiological analysis and spatiotemporal scanning analysis were conducted to analyze the distribution of norovirus outbreaks in China. RESULTS: The outbreaks showed typical seasonality, with more outbreaks in winter and fewer in summer, and the total number of infected cases increased over time. Schools, especially middle schools and primary schools, are the most common settings of norovirus outbreaks, with the major transmission route being life contact. More outbreaks occurred in southeast coastal areas in China and showed significant spatial aggregation. The highly clustered areas of norovirus outbreaks have expanded northeast over time. CONCLUSION By identifying the epidemiological characteristics and high-risk areas of norovirus outbreaks, this study provides important scientific support for the development of preventive and control measures for norovirus outbreaks, which is conducive to the administrative management of high-risk settings and reduction of disease burden in susceptible areas.
Humans ; Gastroenteritis/epidemiology* ; Norovirus ; Caliciviridae Infections/epidemiology* ; Disease Outbreaks ; China/epidemiology* ; Genotype

The prevalence of feline herpesvirus-1 (FHV-1), feline calicivirus (FCV), and Chlamydophila (C.) felis was studied in cats of an animal shelter in Korea. Total 78 cats without ocular and upper respiratory tract disease were examined. Specimens were obtained from ocular conjunctiva and oropharynx. Using multiplex polymerase chain reaction (PCR) and reverse transcription PCR, three pathogens were simultaneously detected. In examined 78 cats, 49 (63%) cats were positive for FHV-1. However, all specimens were negative for C. felis and FCV. In conclusion, many cats recovered from FHV-1 infection remain subclinical carriers in shelter environment.
Animals ; Caliciviridae/genetics ; Caliciviridae Infections/epidemiology/*veterinary ; Cat Diseases/*epidemiology/*microbiology/*virology ; Cats ; Chlamydophila/genetics ; Chlamydophila Infections/epidemiology/*veterinary ; DNA Primers/genetics ; Herpesviridae/genetics ; Herpesviridae Infections/epidemiology/*veterinary ; Housing, Animal ; Korea/epidemiology ; Prevalence ; Reverse Transcriptase Polymerase Chain Reaction

Caliciviridae Infections ; epidemiology ; genetics ; virology ; China ; epidemiology ; Gastroenteritis ; virology ; Humans ; Molecular Epidemiology ; Norovirus ; genetics ; RNA, Viral ; isolation & purification

OBJECTIVE: To investigate the molecular epidemiological characteristics of norovirus (NoV) among children with acute gastroenteritis in Tianjin in 2017. METHODS: A total of 758 stool specimens were collected from the children with acute gastroenteritis possibly caused by viral infection in Tianjin Children's Hospital between January and December, 2017. Quantitative real-time RT-PCR was used for primary screening of NoV, and conventional RT-PCR was used for gene amplification, sequencing and genotype identification of the VP1 region of capsid protein in positive specimens. RESULTS: Among the 758 specimens, 241 (31.8%) were found to have GII NoV. Sequencing of the VP1 region of capsid protein in positive specimens showed that among the 241 specimens with GII NoV, 69 (28.6%) had GII.4 subtype, 51 (21.2%) had GII.3 subtype, 24 (10.0%) had GII.2 subtype, and 18 (7.5%) had other subtypes. There was a significant difference in NoV detection rate between different age groups (P=0.018), and the 1- <4 years group had the highest NoV detection rate (37.3%). There was also a significant difference in NoV detection rate across seasons (P<0.001), and there was a highest NoV detection rate in winter (48.1%). Twenty-seven children (3.6%) had co-infections with NoV and rotavirus. CONCLUSIONS NoV is one of the major pathogens of the children with acute gastroenteritis from Tianjin in 2017. GII genotype, especially GII.4 subtype, is the prevalent strain. NoV infection is commonly seen in children less than 4 years and reaches the peak in winter. Some children are found to have co-infections with rotavirus.
Caliciviridae Infections ; Child ; China ; epidemiology ; Feces ; Gastroenteritis ; epidemiology ; Genotype ; Humans ; Molecular Epidemiology ; Norovirus ; Phylogeny ; RNA, Viral ; Sequence Analysis, DNA

A simple, rapid and sensitive colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) method was established to detect norovirus genotype GII. The method employed a set of six specially designed primers that recognized eight distinct sequences of RNA-dependant RNA polymerase and capsid protein gene for amplification of nucleic acid under isothermal conditions at 65 degrees C for 60 minutes. The amplification process of RT-LAMP was monitored by the addition of HNB (Hydroxy naphthol blue) dye prior to amplification. A positive reaction was indicated by a color change from violet to sky blue and confirmed by agarose electrophoresis. The specificity of the RT-LAMP was validated by detecting several different diarrhea viruses including norovirus genotype GII. The sensitivity was determined by serial dilutions of RNA molecules from in vitro transcription of norovirus genotype GII in parallel with conventional RT-PCR detection. The assay was further evaluated with 93 clinical specimens of diarrhea patients. The results showed that the sensitivity of RT-LAMP was 1 000 copies/microL with a high specificity and the relative sensitivity was at the same level as that of conventional RT-PCR. Positive rate of RT-LAMP in analysis of clinical specimens was approximately the same as that of conventional RT-PCR as well. This colorimetric RT-LAMP assay was potential for rapid detection of norovirus genotype GII on spot due to the observation of visual result with high specificity and sensitivity, time-saving and cost benefit.
Caliciviridae Infections ; diagnosis ; virology ; Colorimetry ; methods ; Feces ; virology ; Genotype ; Humans ; Norovirus ; genetics ; isolation & purification ; Nucleic Acid Amplification Techniques ; methods

OBJECTIVETo investigate the epidemiological and clinical features of calicivirus-associated diarrhea in hospitalized children in Chengdu, China in recent years.

METHODSThe clinical data of 267 children with calicivirus-associated diarrhea aged <5 years who were hospitalized in Chengdu Women and Children's Central Hospital (the only sentinel hospital for sample collection of pediatric viral diarrhea in Chengdu, Sichuan) between January 2012 and December 2014 were retrospectively studied.

RESULTSAmong the 267 children, 200 (74.9%) were aged less than 1 year. The infection rate of calicivirus was 28.4%, 21.6%, and 27.1% in 2012, 2013, and 2014, respectively. Calicivirus was prevalent in summer and autumn (August to October). The detection rate of Norovirus II was 85.8% (229/267), and 244 children (91.4%) experienced an acute clinical course. Watery stool was the most common change in stool properties (82.0%, 219 children), and some specimens showed mucus and/or blood. Most children had moderate to severe fever. One hundred and thirty-eight children (53.9%) experienced a reduced serum prealbumin level. One hundred and fifty-nine children (59.6%) experienced flora imbalance.

CONCLUSIONSCalicivirus has become one of the major pathogens for diarrhea in children aged <5 years in Chengdu, with Norovirus II as the dominant strain. Calicivirus is prevalent in summer and autumn. Infants aged <1 year are the main population affected by calicivirus-associated diarrhea, with watery stool as the most common manifestation.

Adolescent ; Caliciviridae Infections ; epidemiology ; Child ; Child, Hospitalized ; Child, Preschool ; China ; epidemiology ; Diarrhea ; epidemiology ; Female ; Humans ; Infant ; Male ; Time Factors