Dataset Information

An outbreak of norovirus-associated acute gastroenteritis associated with contaminated barrelled water in many schools in Zhejiang, China.

ABSTRACT:

Objectives

More than 900 students and teachers at many schools in Jiaxing city developed acute gastroenteritis in February 2014. An immediate epidemiological investigation was conducted to identify the pathogen, infection sources and route of transmission.

Methods

The probable cases and confirmed cases were defined as students or teachers with diarrhoea or vomiting present since the term began in February 2014. An active search was conducted for undiagnosed cases among students and teachers. Details such as demographic characteristics, gastrointestinal symptoms, and drinking water preference and frequency were collected via a uniform epidemiological questionnaire. A case-control study was implemented, and odds ratios (ORs) and 95% confidence intervals were calculated. Rectal swabs from several patients, food handlers and barrelled water factory workers, as well as water and food samples, were collected to test for potential bacteria and viruses.

Results

A total of 924 cases fit the definition of the probable case, including 8 cases of laboratory-confirmed norovirus infection at 13 schools in Jiaxing city between February 12 and February 21, 2014. The case-control study demonstrated that barrelled water was a risk factor (OR: 20.15, 95% CI: 2.59-156.76) and that bottled water and boiled barrelled water were protective factors (OR: 0.31, 95% CI: 0.13-0.70, and OR: 0.36, 95% CI: 0.16-0.77). A total of 11 rectal samples and 8 barrelled water samples were detected as norovirus-positive, and the genotypes of viral strains were the same (GII). The norovirus that contaminated the barrelled water largely came from the asymptomatic workers.

Conclusions

This acute gastroenteritis outbreak was caused by barrelled water contaminated by norovirus. The outbreak was controlled after stopping the supply of barrelled water. The barrelled water supply in China represents a potential source of acute gastroenteritis outbreaks due to the lack of surveillance and supervision. Therefore, more attention should be paid to this area.

SUBMITTER: Shang X

PROVIDER: S-EPMC5295720 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature

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Publications

An outbreak of norovirus-associated acute gastroenteritis associated with contaminated barrelled water in many schools in Zhejiang, China.

Shang Xiaopeng X Fu Xiaofei X Zhang Peng P Sheng Minyang M Song Jianqiang J He Fan F Qiu Yinwei Y Wu Haocheng H Lu Qinbao Q Feng Yan Y Lin Junfen J Chen Enfu E Chai Chengliang C

PloS one 20170207 2

<h4>Objectives</h4>More than 900 students and teachers at many schools in Jiaxing city developed acute gastroenteritis in February 2014. An immediate epidemiological investigation was conducted to identify the pathogen, infection sources and route of transmission.<h4>Methods</h4>The probable cases and confirmed cases were defined as students or teachers with diarrhoea or vomiting present since the term began in February 2014. An active search was conducted for undiagnosed cases among students an ...[more]

PMID: 28170414

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Project description:BACKGROUND: Between September 17 and October 3, 2009, hundreds of workers employed in a manufacturing factory in Shenzhen, a city in south China developed a sudden onset of acute gastroenteritis. A retrospective cohort study is designed to identify the risk factors and control this outbreak. METHODS: Information on demographic characteristics, working place, the history of contact with a person having diarrhea and/or vomiting, drink water preference and frequency, eating in the company cafeteria or outside the company, hand-washing habits and eating habits is included. Furthermore, in order to find the contamination source, we investigated the environment around the underground reservoir and collected water samples from the junction between municipal supply water system and underground reservoir to test potential bacteria and virus, examine the seepage tracks on the wall of the underground reservoir from the side of septic tank, and check the integrity and attitude of this lid. Relative risk was presented and Chi-square test was performed. All the analyses were performed with OpenEpi software version 2.3.1 online. RESULTS: The cohort study demonstrated that the workers who had direct drink water were 3.0 fold more likely to suffer from acute gastroenteritis than those who consumed commercial bottled water. The direct drinking water, water of the tank of buildings, and the underground reservoir were positive only for norovirus. Norovirus was also detected from stool and rectal swab samples from patients with acute gastroenteritis. The underground reservoir was found to be the primary contamination source. Further environmental investigation showed that the norovirus contaminated substance entered into the underground reservoir via access holes in lid covering this underground reservoir. CONCLUSION: This acute gastroenteritis outbreak was caused by the secondary supply system contaminated by norovirus in this factory. The outbreak of gastroenteritis cases caused by norovirus frequently occurred in China due to a lack of surveillance and supervision, and due to faults in the construction of such water systems. Therefore, more attentions should pay to the secondary supply water system in China.

Project description:BackgroundAn outbreak of acute gastroenteritis occurred in a kindergarten located Shenzhen City on March 4, 2018. We were invited to investigate to the risk factors associated with this outbreak.MethodsWe conducted retrospective cohort-studies on three different groups of subjects in order to figure out the difference of incidence of acute gastroenteritis among subjects of different activities on March 2: group one consisted of people who attended the Lantern festival activities; group two consisted of children and employees who ate breakfast and bread provided by the kindergarten; and groups three consisted of children and employees who did not eat breakfast or bread provided by the kindergarten. Fecal, anal swabs, dishware swabs and hand swabs specimens were collected in the study. Bacteria known to cause acute gastroenteritis were cultured. Viruses associated with acute gastroenteritis were tested using real-time PCR. Capsid gene fragment of 557 bp of norovirus was amplified and sequenced. The phylogenetic tree was constructed with MEGA 7.0 using neighbor-joining method based on capsid gene fragment of norovirus.ResultsA total of 143 suspected cases were identified in this outbreak. Diarrhea happened more often in adults than in children while emesis and bellyache were more frequently found in children than in adults. Higher AGE incidence was observed in group 2, children and employees who had breakfast in the kindergarten on March 2, as well as in group 3, and among employees who eating bread involved in breakfast provided on March 2. Five anal swab specimens were positive for norovirus. All noroviruses belongs to group II.3 and have an identity more than 99%.ConclusionA chef, as an asymptomatic carrier with norovirus, was the infectious resource in this outbreak. He contaminated breakfast food provided on March 2. Although morning check is implemented in kindergartens of China, employees are often excluded in morning check. Our finding highlights the importance of morning check covering employees and periodical training for cooks.

Project description:BackgroundIn February 2015 an outbreak of gastroenteritis occurred in a distillery in Kinmen, Taiwan. At least 450 affected employees developed the symptoms of diarrhea and vomiting after attending a lunch banquet on 6 February. Epidemiological, laboratory and environmental investigations were conducted to identify the agent and source of this outbreak.MethodsA case-control study was carried out among lunch attendees from the distillery. Using a semi-structured questionnaire, food and beverage consumption in the lunch banquet was assessed, as well as demographic and clinical data of the exposed people. An outbreak case was defined as a diner who developed at least three following symptoms: diarrhea, vomiting, abdominal pain, nausea, chills and/or weakness in the 72 h following the lunch. Controls were defined as lunch attendees who did not have any of the above symptoms. Rectal swabs or stool samples of the symptomatic exposed diners and food handlers as well as food and environmental samples were collected to test potential bacteria and viruses. Norovirus was detected by reverse transcription-polymerase chain reaction and sequence analysis. An environmental assessment, including environmental inspection of the restaurant and a review of work practices of food workers, was undertaken.ResultsOf 363 respondents with complete data, 169 met the case definition and 111 met the control definition. Consumption of pork liver in cold appetizers (adjusted odd ratio (aOR) 3.23; 95 % confidence interval (CI): 1.26-8.30) and lamb chops (aOR: 3.98, 95 % CI: 1.74-9.11) were each associated with increased risk of illness. No cases but two asymptomatic food handlers who prepared or cooked the implicated foods tested positive for norovirus genotype I.6. Food and environmental samples were negative for any bacteria. Environmental assessment indicated that hand washing facilities were not properly accessible to food handlers. Inappropriate hygiene practices in food handlers may have contributed to food contamination.ConclusionOur investigation suggests that etiological agent of this outbreak was norovirus. The food vehicles were pork liver and lamb chops, which may have been contaminated by asymptomatic infected food handlers. Strict adherence to hand hygiene practices and access to hand washing facilities should be reinforced to prevent such foodborne outbreaks.

Dataset Information

An outbreak of norovirus-associated acute gastroenteritis associated with contaminated barrelled water in many schools in Zhejiang, China.

Objectives

Methods

Results

Conclusions

Publications

An outbreak of norovirus-associated acute gastroenteritis associated with contaminated barrelled water in many schools in Zhejiang, China.

Similar Datasets

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