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Objective To understand the pathogen composition of viral diarrhea in Chongqing, and to provide reference for the prevention and control of viral diarrhea. Methods Real-time fluorescent RT-PCR was used to detect the nucleic acids of rotavirus, norovirus, sapovirus, astrovirus, and enteric adenovirus collected from diarrhea outpatient cases from 2018 to 2019, and the positive nucleic acid samples were sequenced. Results Among the 398 cases of diarrhea, 184 cases were detected positive, with the positive detection rate of 46.23%. Norovirus infection was the main infection, accounting for 29.40%. The G/P genotype of group A rotavirus was mainly G9P8, accounting for 90.32%. The genotype of norovirus was mainly GII.2[P16], accounting for 33.91%. The genotype of sapovirus was mainly GI.2, accounting for 55.56%. The genotype of astrovirus was HAstV-4, accounting for 100%. The genotype of enteric adenovirus was F41, accounting for 100%. The diarrhea cases were mainly distributed in the fourth quarter, with the positive detection rate of 70.42%, among which norovirus had the highest detection rate, accounting for 53.99%. Conclusion High incidence of viral diarrhea is in winter in Chongqing. The main pathogen of viral diarrhea is norovirus, and the genotypes of norovirus show diversity. It is necessary to prevent the outbreak and epidemic caused by norovirus in winter. In the future, the surveillance of viral diarrhea should be strengthened, and the viral diarrhea gene database should be improved to provide a scientific basis for epidemic prevention and control.
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Objective To analyze the epidemiological characteristics of norovirus infectious diarrhea in the active monitoring of foodborne diseases in Jiangsu Province from 2015 to 2020, so as to provide reference for the prevention and control of foodborne diseases caused by norovirus. Methods Norovirus positive diarrhea cases were collected from sentinel hospitals in 13 districts and cities of Jiangsu Province, and their epidemiological and clinical characteristics were analyzed. Results Atotal of 3 620 norovirus positive cases were detected and isolated from 61 489 samples. The main serotype was GII (71.97%), the onset season was winter and spring, and the onset age was 1-3 years old and 14-34 years old. There was no significant difference in norovirus positive rate between different sexes, and the main symptom was diarrhea (incidence rate was 92.10%), Meat and meat products (20.20%) were the main types of suspected exposed foods. Conclusion Norovirus infection has obvious seasonal characteristics, and the population is generally susceptible. It is high in children and young people, and meat food was the main suspicious exposure food. We should continue to improve the ability of active monitoring, identification, early warning and control of foodborne diseases, so as to reduce the occurrence of foodborne diseases.
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Objective@#To investigate the epidemiological characteristics of 45 norovirus clusters in Baoshan District, Shanghai Municipality from 2019 to 2021, so as to provide the evidence for improving the management of norovirus clusters. @*Methods@#The epidemiological characteristics and laboratory testing of 45 norovirus clusters were collected in Baoshan District from 2019 to 2021, and the temporal distribution, population distribution, distribution of places of norovirus clusters, clinical manifestations, laboratory testing results, origin of norovirus infection and transmission routes of norovirus clusters were analyzed using a descriptive epidemiological method. @*Results@#A total of 45 norovirus clusters involving 29 379 individuals were reported in Baoshan District from 2019 to 2021, and 435 cases with norovirus infections were identified, with an average attack rate of 1.48%. Norovirus infection most often occurred from November to April of the following year, and the infection predominantly occurred among students (408 cases, 93.79%). There were 25 norovirus clusters in kindergartens (55.56%), 18 clusters in primary and middle schools (40.00%), one cluster in a social care facility and one cluster in a geriatric ward. Vomiting was the predominant clinical symptom (416 cases, 95.63%). The positive rate of norovirus was 37.35% in 597 samples. There were 40 norovirus clusters caused by the norovirus GⅡ genotype (88.89%), and the median duration of the norovirus cluster was 6 days (interquartile range, 1 day). In addition, 82.22% of the norovirus clusters reported to centers for disease control and prevention within 1 day,and 88.89% of the clusters were transmitted through human to human transmission or vomitus of cases.@*Conclusion@#The norovirus clusters predominantly occur in winter/spring and among students in Baoshan District from 2019 to 2021. Kindergartens and primary and middle schools are main places of norovirus infections, and the norovirus GⅡ genotype is the main type of pathogens. Human-to-human transmission and exposure to patients' vomitus are the main routes of transmission.
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Objective@#To investigate the epidemiological and etiological characteristics of viral diarrhea among children under 5 years of age in Shaoxing City, Zhejiang Province, so as to provide insights into management of viral diarrhea.@*Methods@#The surveillance data on viral diarrhea among children under 5 years of age in Shaoxing City from 2019 to 2022 were collected, including demographics and stool testing results. The epidemiological and etiological characteristics of viral diarrhea were analyzed using a descriptive epidemiological method. @*Results@#A total of 763 diarrheal children under 5 years of age were reported in Shaoxing City from 2019 to 2022, and 236 children were tested positive for virus (30.93%). The detection of virus was 49.01%, 31.61%, 20.43% and 21.89% from 2019 to 2022, which appeared an overall tendency towards a decline (P<0.05). The incidence of viral diarrhea peaked from November to March of the next year and from May to July, and the detection of virus was lower among children with diarrhea living in urban areas (Yuecheng District, Keqiao District and Shangyu District) than among those in suburb areas (Zhuji City, Shengzhou City and Xinchang County) (30.22% vs. 52.00%, P<0.05). There were 206 children tested positive for a single virus, and the detection rates of rotavirus (RV), enteric adenovirus (EAdV), norovirus (NoV), and sapovirus (SaV) were 9.57%, 8.91%, 8.39%, and 0.13%, respectively. There were 25 children with virus co-infections, and the positive rates of EAdV and NoV, RV and EAdV and RV and NoV co-infections were 1.31%, 1.18% and 0.79%, respectively. There were 5 children with triple infections of RV, EAdV and NoV (0.66%). The highest detection of EAdV was seen in April, the highest detection of RV and NoV was seen in January, while SaV was only detected in April. @*Conclusion@#The incidence of viral diarrhea among children under 5 years of age peaked in winter and spring in Shaoxing City from 2019 to 2022, and the cases predominantly occurred in urban areas. The detection of virus appeared an overall tendency towards a decline, with high detection of RV, EAdV and NoV.
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@#Objective To analyze the evolutionary characteristics of GZ19 strain of G Ⅱ.4 norovirus(NoV) in China,and clarify its ability and mode of binding to receptors of histo-blood group antigens(HBGAs).Methods According to the sequence of ORF2 region in GZ19 strain,the evolutionary tree was constructed and the amino acid sequences at HBGA binding sites(HBSs) and key blocking epitopes were analyzed.P particles were expressed by prokaryotic expression system and purified.The obtained protein was identified by SDS-PAGE and indirect ELISA,and analyzed for the receptor binding characteristics of P particles by saliva binding and oligosaccharide binding assays.Results The GZ19 strain belonged to G Ⅱ.4Sydney [P31] lineage,of which the amino acid sequences of receptor binding sites and blocking epitopes were relatively conservative.It showed high homology with other G Ⅱ.4 Sydney [P31] strains in recent five years,while significant difference from G Ⅱ.4 Sydney 2012 original strain and G Ⅱ.4 Sydney [P16] strains.P particles only combined with A,B,O,AB secretory saliva and H-di oligosaccharide.Conclusion GZ19 strain represented the current evolutionary direction of G Ⅱ.4Sydney [P31] NoV.The successful expression of P particles and analysis of the binding characteristics with HBGA receptors laid a foundation of the research of epidemic evolution dynamics and vaccine development of G Ⅱ.4 NoVs in China.
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@#Abstract: Objective To analyze the epidemiological characteristics and related factors of norovirus in Guangxi from 2015 to 2020, and to provide scientific recommendations for norovirus prevention and control. Methods The foodborne diseases surveillance data were collected from 11 sentinel hospitals through the National Foodborne Disease Monitoring and Reporting System from 2015 to 2020. R software with version 4.0.3 was used for descriptive and statistical analysis, including epidemic curve, chi-square test, and trend chi-square and so on. Logistic regression was used to analyze norovirus-related factors, OR values and 95% confidence intervals were calculated respectively with the statistical test level of P<0.05. Results There were 1 008 norovirus cases detected, with a detection rate of 12.75% (1 008/7 903). Children with age less than 5 years (OR=1.43, 95%CI: 1.13-1.82) and patients at age 20-45 (OR=1.45, 95%CI: 1.13-1.87) were high risk population. The detection rate was higher in autumn (OR=1.29, 95%CI: 1.08-1.53) but lower in summer (OR=0.67, 95%CI: 0.55-0.80). In addition, the tourist area (Guilin City) presented a higher detection rate than other areas (OR=1.41, 95%CI: 1.10-1.80). Aquatic products (OR=1.40, 95%CI: 1.03-1.91), meat and dairy products (OR=1.31, 95%CI: 1.06-1.61) were high-risk foods for norovirus infection. The prevention and control policies of COVID-19 can reduce the possibility of norovirus by 61% (OR=0.39, 95%CI: 0.31-0.49) showed a declining trend (Trend χ2=85.33, P<0.001). In addition, prolonged visit time can lead to 19%-23% decrease in the detection rate of norovirus (OR24-48 hours=0.81, 95%CI: 0.70-0.95; OR>48 hours=0.77, 95%CI: 0.63-0.93). Conclusions The epidemic of norovirus presented seasonal and regional distribution in Guangxi with a declining detection rate trend in diarrhea patients during recent 6 years. Young children were high-risk population in infection norovirus. The intake of seafood can increase the risk of norovirus infection. The prevention and control policies of COVID-19 can sharply decrease the possibility of infection norovirus. The monitoring of key foods such as seafood should be strengthened, and the early screening of suspected cases should be taken. The norovirus monitoring should be improved to ensure the health of the population.
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Diarrhea is a frequent complication after kidney transplantation, which is a common clinical manifestation of prevalent diseases following multiple types of organ transplantation. The common causes of diarrhea after kidney transplantation include adverse reactions of immunosuppressants, infectious diseases and de novo postoperative inflammatory bowel disease, etc. Diarrhea could seriously affect the quality of life of kidney transplant recipients, and may lead to allograft dysfunction or even death of recipients. Because the causes of diarrhea after kidney transplantation are complicated and probably overlap with each other, along with individual differences among recipients, the etiological diagnosis and targeted treatment of diarrhea after kidney transplantation should follow the principles of gradual and phased treatment. In this article, the epidemiology and harm, common causes and management strategies of diarrhea after kidney transplantation were summarized, aiming to deepen the clinicians' understanding and enhance the diagnosis and treatment levels of diarrhea after kidney transplantation, thereby improving the quality of life and prognosis of kidney transplant recipients.
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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.
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Humans , Gastroenteritis/epidemiology , Norovirus , Caliciviridae Infections/epidemiology , Disease Outbreaks , China/epidemiology , GenotypeABSTRACT
Las precipitaciones extremas representan uno de los eventos naturales climáticos más importantes y pueden originar inundaciones devastadoras. De junio a agosto del 2014 se registró una de las más graves inundaciones en la historia de la ciudad de Asunción. Ocasionó un incremento considerable del nivel del río Paraguay y el desplazamiento de 300.000 personas a campamentos provisionales. Debido a que el contacto directo con el agua de inundación, el consumo de agua contaminada y la congregación de los afectados en refugios provisorios son factores de riesgo para enfermedades infecciosas, el objetivo de este estudio fue la implementación de una metodología estandarizada para la concentración y detección de virus entéricos y micobacterias no tuberculosas, por PCR en tiempo real y PCR-asociada al análisis de restricción enzimática (PRA), en muestras de agua de inundaciones y el reporte de los patógenos detectados en las zonas afectadas de Asunción y en la Bahía del Río Paraguay. La metodología propuesta demostró poseer buena sensibilidad y se registró la presencia de rotavirus, norovirus (genogrupos I y II), astrovirus, adenovirus entéricos y micobacterias no tuberculosas en 50% (N=4/8) de las muestras de los barrios Sajonia, San Jerónimo y Ricardo Brugada, Chacarita. Además, reportamos datos secundarios de casos de enfermedades infecciosas, registrados en los servicios de salud de los barrios afectados durante el periodo de inundación.
Extreme rainfall represents one of the most important natural climatic events and can cause devastating floods. From June to August 2014, one of the most serious floods in the history of the city of Asunción was recorded. It caused a considerable increase in the level of the Paraguay River and the displacement of 300,000 people to temporary camps. Since direct contact with flood water, consumption of contaminated water and the congregation of those affected in temporary shelters are risk factors for infectious diseases, the objective of this study was the implementation of a standardized methodology for the concentration and detection of enteric viruses and non-tuberculous mycobacteria, by real-time PCR and PCR-associated enzyme restriction analysis (PRA), in samples of flood water and the report of the pathogens detected in the affected areas of Asunción and in the Bay of the Paraguay River. The proposed methodology proved to have good sensitivity and the presence of rotavirus, norovirus (genogroups I and II), astrovirus, enteric adenovirus and non-tuberculous mycobacteria was recorded in 50% (N=4/8) of the samples from the Sajonia, San Jeronimo and Ricardo Brugada, Chacarita neighborhoods. In addition, we report secondary data on cases of infectious diseases, registered in the health services of the affected neighborhoods during the flood period.
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ObjectiveTo determine the epidemiological characteristics and risk factors of a norovirus GII.17 outbreak in Minhang District of Shanghai in 2018， and provide evidence for prevention and control measures of norovirus infection. MethodsDescriptive epidemiological analysis was performed. In addition， a retrospective cohort study was conducted to determine the risk factors. ResultsFrom May 30th to June 1st of 2018， a total of 132 cases （126 clinical cases and 6 confirmed cases） were documented，with an attack rate of 29.20%（132/452）.All cases were children in a kindergarten， with the average age of 5 years and 43.9% being male. The cases were reported in all the classes， with no clustering by class or floor．The epidemic curve was characterized by a point source exposure， which was estimated to be probably between 7 AM on May 30thand 0：30 AM on May 31st. The retrospective cohort study showed that the attack rate significantly differed between the children who had taken and did not take the school lunch （RR=∞） on May 30th，and those who had taken and did not take seafood noodles （RR=4.11， 95%CI：1.09-15.55） （P<0.05）. Among a total of 73 specimens， six specimens collected in child cases and one specimen in an asymptomatic chef tested positive for GII.17 type of norovirus. In addition， one retained food specimen of seafood noodles was positive for Aeromonas hydrophila. Viral shedding in the asymptomatic chef remained over 30 days. ConclusionThe outbreak was caused by seafood noodles contaminated by norovirus. It warrants enhancement in the regulation of food safety in canteens and regular examination of norovirus infection in catering industry employees.
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ObjectiveTo determine the epidemiological characteristics of norovirus infections in Lin’an District， Hangzhou City from 2012 to 2020， and provide scientific evidence for improving preventive and control measures. MethodsDescriptive epidemiological methods were used to characterize the epidemic and conduct statistical analysis to determine related factors. ResultsA total of 37 clustered outbreaks of norovirus infection were reported in Lin’an District of Hangzhou from 2012 to 2020， including 8 outbreaks in kindergartens， 15 ones in elementary schools， 8 ones in middle and high schools， 2 ones in universities， and 4 other ones. The total number of cases with norovirus infection was 1 194， with the average attack rate of 3.76%. The incidence of norovirus was higher in winter and spring. It was also higher in urban areas， followed by suburban and mountainous areas neighbored to traffic lines. Moreover， attack rates differed significantly by transmission routes， including mixed contact and aerosol transmission， contact transmission， food-borne transmission， and water-borne transmission （χ2=186.91，P<0.001）. There was significant difference in the incidence among kindergartens， schools， and universities （χ2=980.15，P<0.001）. In the 37 outbreaks， norovirus were mainly classified as GⅡ in the 34 ones （accounting for 91.89%）， and GⅠ in the remaining 3 ones. ConclusionThe epidemic of norovirus infection in Lin’an District， Hangzhou City is characterized by certain population， time， space， transmission routes， and strains. It warrants enhanced health education and promotion， preparedness and response plan， syndromic surveillance， early alerting， school closure， and environmental disinfection for further prevention and control of norovirus infection.
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Objective: “Housing for the elderly” is a type of facility where a few healthcare staff and care workers provide long-term care to residents. This study aimed to explore the infection control measures promoted by the public health centers (PHC) when a cluster of norovirus cases occurred in this type of facility.Materials and Methods: This study involved a prefectural office in Japan and collected the records of PHC surveys/instructions of norovirus cluster cases that occurred in “housing for the elderly” facilities between 2017 and 2019. The records provided information about the case characteristics (cluster periods and number of infected individuals) and instructions for infection control by the PHC. We tabulated the case characteristics and performed a descriptive qualitative analysis to extract the instructions from the PHC.Results: Twelve clusters of cases were included in the study. Approximately 16% of the residents and care workers in each facility were infected, and it took an average of 23 days from the start of the outbreak to the end. Nine categories of PHC instructions emerged after the data analysis. “Collaboration with community healthcare workers” included instructions by the PHC to share information with external physicians and home-visiting nurses. In “precautions when caring for elderly residents with functional decline”, the procedure for changing diapers and infection control measures considering the behavior of residents with dementia were advised. If the contents of the infection control manuals were deemed to be inadequate, an “improvement of the infection control manuals” was instructed.Conclusion: To implement effective infection control by care workers at “housing for the elderly” facilities, the PHC should promote the involvement of community physicians and nurses and advise on clear procedures based on residents’ functional decline.
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Objective:To analyze the changes of common pathogens of viral diarrhea in children during the COVID-19 epidemic.Methods:A retrospective analysis was performed on children with acute diarrhea treated in Children’s Hospital affiliated to Zhejiang University School of Medicine from 2019 April to 2019 December(before COVID-19, n=407)and 2020 April to 2020 December (during COVID-19, n=645). Children were further divided into 1-6 months, >6 months-2 years, >2-5 years age groups. Detection rates of norovirus GI (NOVI), norovirus GⅡ (NOVⅡ), rotavirus A (ROVA), rotavirus C (ROVC), intestinal adenovirus (EADV), sapovirus (SAV) and astrovirus (ASV) in different age groups and seasons before and during COVID-19 were compared by χ2 or Fisher exact test. Results:The total detection rates of diarrhea-causing viruses among age groups were significantly higher before COVID-19 than those during COVID-19( χ2=8.43, 38.22 and 9.23, all P<0.05). The detection rates of NOVⅡ and EADV in infants aged 1-6 months and >6 months-2 years were decreased during the period of COVID-19 epidemic( χNOVⅡ2 =36.87 and 17.77, both P<0.001, χEADV2 =9.08, P=0.014 and 0.003); the detection rates of NOVⅡ in children aged 2-5 years was decreased during the period of COVID-19 epidemic( χ2=3.96, P=0.047); the detection rates of other diarrhea-causing viruses were not decreased during the period of COVID-19 epidemic(all P>0.05). The detection rates of diarrhea-causing viruses among 4-6 months, 7-9 months and 10-12 months were higher during the period of COVID-19 epidemic( χ2=11.62, 65.41 and 27.80, all P<0.001). Conclusion:After the outbreak of COVID-19, the detection rate of common pathogens of viral diarrhea in children is decreased, especially NOVⅡ and EADV, which may be related to the measures in response to major public health events in Zhejiang Province.
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Foodborne viruses including hepatitis A virus (HAV), norovirus (NoV), rotavirus (RoV) and hepatitis E virus (HEV) are easily transmitted through contaminated seafoods. The current research was done to assess the incidence of RoV, NoV GI and GII,hAV and hEV in fish and shrimp samples caught from the Persian Gulf, Iran. Three-hundred and twenty fish and shrimp samples were collected. The presence of foodborne viruses were assessed by the real-time PCR. Forty-nine out of 320 (15.31%) fish and shrimp samples were positive for foodborne viruses. Distribution of hAV, NoV GI and NoV GII amongst all studied samples were 0.93%, 5.93% and 8.43%, respectively. hEV and RoV viruses were not found in studied samples. Parastromateus niger and Scomberomorus commerson fish and Penaeus monodon shrimp were the most frequently contaminated samples. Simultaneous incidence of hAV and NoV GI and hAV and NoV GII were 0.31% and 0.93%, respectively. Distribution of foodborne viruses in samples collected through spring, summer, autumn and winter seasons were 14.28%, 9.33%, 11.76% and 24.44%, respectively. Findings revealed that the incidence of foodborne viruses was significantly associated with seafood species and also season of sampling.(AU)
Vírus transmitidos por alimentos, incluindo hepatite A (HAV), norovírus (NoV), rotavírus (RoV) e hepatite E (HEV) são facilmente transmitidos através de frutos do mar contaminados. Esta pesquisa foi realizada para avaliar a incidência de RoV, NoV GI e GII, hAV e hEV em amostras de peixes e camarões capturadas no Golfo Pérsico, Irã. Foram coletadas 300 amostras de peixes e camarões. A presença de vírus transmitidos por alimentos foi avaliada por PCR em tempo real. Quarenta e nove das 320 amostras de peixes e camarões (15,31%) foram positivas para vírus transmitidos por alimentos. A distribuição de hAV, NoV GI e NoV GII entre as amostras estudadas foi 0,93%, 5,93% e 8,43%, respectivamente. Os vírus hEV e RoV não foram encontrados nas amostras estudadas. Os peixes Parastromateus niger e Scomberomorus commerson e o camarão Penaeus monodon foram as amostras mais frequentemente contaminadas. A incidência simultânea de hAV e NoV GI, e hAV e NoV GII foi de 0,31% e 0,93%, respectivamente. A distribuição dos vírus transmitidos por alimentos nas amostras coletadas na primavera, verão, outono e inverno foi de 14,28%, 9,33%, 11,76% e 24,44%, respectivamente. Os resultados demonstram que a incidência de vírus transmitidos por alimentos foi significativamente associada às espécies de frutos do mar e também à época da amostragem.(AU)
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Animals , Rotavirus Infections/epidemiology , Decapoda/virology , Hepatitis E/epidemiology , Caliciviridae Infections/epidemiology , Fishes/virology , Hepatitis A/epidemiology , Shellfish/virology , Hepatitis E virus/isolation & purification , Rotavirus/isolation & purification , Indian Ocean/epidemiology , Hepatitis A virus/isolation & purification , Norovirus/isolation & purification , Iran/epidemiologyABSTRACT
ObjectiveTo investigate the prevalence and epidemiological characteristics of norovirus in adult cases with infectious diarrhea in Putuo District of Shanghai， and provide scientific evidence for the prevention and control of infectious diarrhea caused by norovirus. MethodsFecal samples， clinical information and epidemiological data were collected from January 2013 through December 2019 in surveillance hospitals in Putuo District of Shanghai. Norovirus was examined by real-time fluorescent quantitative reverse transcription polymerase chain reaction （rRT-PCR）. ResultsIn 1 389 adult cases with infectious diarrhea， norovirus positive rate was 25.41%， which was significantly higher in male （27.16%） than female （23.89%）. Furthermore， in 353 cases positive for norovirus， GⅡ group was the most common （77.98%）.The positive rate was highest in the cases aged 30-44 years. Spring， autumn and winter were the seasons with higher incidence of norovirus （September to May）. The norovirus-infected cases had more nausea， vomiting， hyperactivity of bowel sounds， and watery stool， compared to the negative cases （P<0.05）. ConclusionThe detection rate of norovirus remains high in adult cases with infectious diarrhea in Putuo District of Shanghai， of which GII is predominant. Seasonality may be spring， autumn and winter. Therefore， it warrants the countermeasures， such as surveillance and health education， for prevention and control of norovirus in susceptible population during epidemic seasons.
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ObjectiveTo investigate the prevalence and epidemiological characteristics of norovirus in adult cases with infectious diarrhea in Putuo District of Shanghai， and provide scientific evidence for the prevention and control of infectious diarrhea caused by norovirus. MethodsFecal samples， clinical information and epidemiological data were collected from January 2013 through December 2019 in surveillance hospitals in Putuo District of Shanghai. Norovirus was examined by real-time fluorescent quantitative reverse transcription polymerase chain reaction （rRT-PCR）. ResultsIn 1 389 adult cases with infectious diarrhea， norovirus positive rate was 25.41%， which was significantly higher in male （27.16%） than female （23.89%）. Furthermore， in 353 cases positive for norovirus， GⅡ group was the most common （77.98%）.The positive rate was highest in the cases aged 30-44 years. Spring， autumn and winter were the seasons with higher incidence of norovirus （September to May）. The norovirus-infected cases had more nausea， vomiting， hyperactivity of bowel sounds， and watery stool， compared to the negative cases （P<0.05）. ConclusionThe detection rate of norovirus remains high in adult cases with infectious diarrhea in Putuo District of Shanghai， of which GII is predominant. Seasonality may be spring， autumn and winter. Therefore， it warrants the countermeasures， such as surveillance and health education， for prevention and control of norovirus in susceptible population during epidemic seasons.
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Objective To understand the dynamic changes of the pathogen spectrum of viral diarrhea in Southwest China, and to provide a scientific basis for formulating prevention and control measures. Methods A total of 2 262 fecal samples of diarrhea cases were collected from the diarrhea monitoring sites in Yunnan, Sichuan, and Chongqing from January 2017 to December 2019. The detection of rotavirus, norovirus, adenovirus, astrovirus, and sapovirus was performed by real-time PCR, and their epidemiological data were collected. Results The ratio of male to female patients was 1.30:1. The majority of patients were 3 years old and younger, accounting for 52.21%% of all cases. Children living at home accounted for 49.38% of all cases. The detection rate of rotavirus was 10.70%, followed by norovirus at 10.43% and adenovirus at 4.60%. The detection rate of rotavirus was the highest in Yunnan and Chongqing, which were 20.18% and 16.96%, respectively, while the detection rate of norovirus was the highest in Sichuan, which was 13.54%. Conclusion Rotavirus was still the main diarrheal pathogen in Southwest China. High incidence of diarrhea occurred in autumn and winter, with children living at home being the main patients. Measures should be taken to prevent outbreaks caused by norovirus and adenovirus.
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Objective To understand the epidemiological characteristics of norovirus infectious diarrhea in Pudong New Area of Shanghai, and to provide reference for prevention and control of diarrhea caused by norovirus. Methods Epidemiological data and stool samples from diarrhea cases of 15 hospitals in 2015-2019 years were collected. The two subtypes of norovirus G I and G II were detected by RT-PCR and analyzed. Results A total of 9 397 diarrhea samples were collected in 2015-2019 years, and 1 938 positive norovirus samples were detected, with a positive rate of 20.62%. The majority of serotypes were GII (88.60%). Diarrhea caused by norovirus occurs all year round, with high incidence season in 2-3and 10-12 months every year. There was no significant difference in the positive rate of norovirus between different sexes（χ2=2.611，P=0.106）. The positive rate of the 15-64 year old group was higher than that of the 0-14 year old group and the 65 year old and above group（χ2=153.634，P<0.001）. The highest positive rate was for cadres /worker/ business services / teachers / medical staff / drivers. The positive rate of norovirus in diarrhea cases with vomiting was significantly higher than that in patients without vomiting. Conclusions Diarrhea caused by norovirus is related to season, age and occupation. Because there is no effective antiviral drugs and vaccine prevention, continuous monitoring should be carried out and targeted preventive measures should be carried out according to epidemiological characteristics.
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Objective To investigate an outbreak of norovirus GII gastroenteritis in a school, and explore the causes, transmission routes and risk factors of the outbreak, and to provide a scientific basis and experience for effective control of outbreaks of acute gastroenteritis in schools. Methods A case study of an acute gastroenteritis outbreak in a school in Wujin District, Changzhou was conducted by field epidemiological investigation. Anal swab samples of patients and controls were collected, and enterovirus nucleic acid was detected by real-time fluorescent PCR. Results From December 12 to December 17, 2019, a total of 185 cases were identified, all of them from students of the school, with an incidence rate of 3.84% (185/4,822). All of the cases were distributed in three (7th/8th/9th) grades of the school, with attack rates of 5.38% (31 / 576), 18.71% (104 / 556) and 9.06% (50 / 552) in 7th, 8th and 9th grade, respectively, showing a significant difference among the grades (χ2=54.47，P＜0.05). The attack rate of each floor of the teaching building from the first to fifth floor was 2.17% (5/230), 7.51% (26/346), 15.77% (53/336), 17.11% (65/380), and 6.38% (25/392), respectively, showing a statistically significant difference among different floors (χ2=55.66，P＜0.05). A total of 32 anal swabs were collected, including 12 patients, 10 control students and 10 workers in the canteen. Of them, 9 specimens of the patients and 1 specimen of the workers were positive for norovirus type GII. Conclusion The school outbreak of acute gastroenteritis was caused by norovirus GII. Close contact between students was the main mode of transmission. A hidden infection of canteen staff may be related to this outbreak. It is important to promote popular science of norovirus prevention and to enhance the awareness of the risks of the virus.
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Objective:This study aimed to investigate the time duration of norovirus shedding among day-care children and students during norovirus outbreaks， as well as influencing factors affecting the viral shedding. Methods:Suspected cases of norovirus infection and their close contacts were collected from child care and school settings during norovirus outbreaks in Xuhui District， Shanghai， from 2017 through 2019. Specimens were detected using real-time RT-PCR to determine whether children had been infected with norovirus. Subsequently， further specimens were collected every 3-7 days from infected children until specimens tested negative for norovirus. Results:A total of 76 outbreaks were reported involving 1 014 suspected cases. In the 421 suspected cases， 311 confirmed cases were diagnosed after examination. Furthermore， a total of 58 confirmed cases participated in this study with informed consent， with a participation rate of 18.65%. The average time duration of norovirus shedding was （16.24±13.80） days， in which 79.31% had viral shedding more than 7 days， 37.93% more than 14 days and 17.24% more than 21 days. A Cox proportional-hazards model showed that children with more severe symptoms （HR=2.06，P=0.040）， day-care children （HR=4.13，P=0.012）， and confirmed cases in 2019 （HR=0.11，P<0.001） had longer duration of viral shedding. Conclusion:Children may remain shedding norovirus after their recovery and back to class. Improvement in sanitation for these recovered children in child care and schools is especially necessary， which may avert secondary transmission.