An outbreak of norovirus-related acute gastroenteritis associated with delivery food in Guangzhou, southern China

Measures for preventing norovirus outbreaks on campus in economically underdeveloped areas and countries: evidence from rural areas in Western China

Background

The outbreak of norovirus represents a significant public health emergency within densely populated, impoverished, and underdeveloped areas and countries. Our objective is to conduct an epidemiology study of a norovirus outbreak that occurred in a kindergarten located in rural western China. We aim to raise awareness and garner increased attention towards the prevention and control of norovirus, particularly in economically underdeveloped regions.

Methods

Retrospective on-site epidemiological investigation results, including data on school layout, case symptoms, onset time, disposal methods and sample testing results, questionnaire surveys, and case-control study were conducted in a kindergarten to analyze the underlying causes of the norovirus outbreak.

Results

A total of 15 cases were identified, with an attack rate of 44.12% (15/34). Among them, 10 cases were diagnosed through laboratory tests, and 5 cases were diagnosed clinically. Vomiting (100%, 15/15) and diarrhea (93.33%, 14/15) were the most common symptoms in the outbreak. Case control study revealed that cases who had close contact (<1 m) with the patient's vomitus (OR = 5.500) and those who had close contact with similar patients (OR = 8.000) had significantly higher ORs compared to the control participants. The current study demonstrated that improper handling of vomitus is positively associated with norovirus outbreak. The absence of standardized disinfection protocols heightens the risk of norovirus outbreaks.

Conclusion

To our knowledge, this study represents the first investigation into a norovirus outbreak in rural areas of western China. We aspire that amidst rapid economic development, a greater emphasis will be placed on the prevention and control of infectious diseases in economically underdeveloped areas and countries.

Spatio-temporal pattern and associate factors of intestinal infectious diseases in Zhejiang Province, China, 2008-2021: a Bayesian modeling study

BACKGROUND

Despite significant progress in sanitation status and public health awareness, intestinal infectious diseases (IID) have caused a serious disease burden in China. Little was known about the spatio-temporal pattern of IID at the county level in Zhejiang. Therefore, a spatio-temporal modelling study to identify high-risk regions of IID incidence and potential risk factors was conducted.

METHODS

Reported cases of notifiable IID from 2008 to 2021 were obtained from the China Information System for Disease Control and Prevention. Moran's I index and the local indicators of spatial association (LISA) were calculated using Geoda software to identify the spatial autocorrelation and high-risk areas of IID incidence. Bayesian hierarchical model was used to explore socioeconomic and climate factors affecting IID incidence inequities from spatial and temporal perspectives.

RESULTS

From 2008 to 2021, a total of 101 cholera, 55,298 bacterial dysentery, 131 amoebic dysentery, 5297 typhoid, 2102 paratyphoid, 27,947 HEV, 1,695,925 hand, foot and mouth disease (HFMD), and 1,505,797 other infectious diarrhea (OID) cases were reported in Zhejiang Province. The hot spots for bacterial dysentery, OID, and HEV incidence were found mainly in Hangzhou, while high-high cluster regions for incidence of enteric fever and HFMD were mainly located in Ningbo. The Bayesian model showed that Areas with a high proportion of males had a lower risk of BD and enteric fever. People under the age of 18 may have a higher risk of IID. High urbanization rate was a protective factor against HFMD (RR = 0.91, 95% CI: 0.88, 0.94), but was a risk factor for HEV (RR = 1.06, 95% CI: 1.01-1.10). BD risk (RR = 1.14, 95% CI: 1.10-1.18) and enteric fever risk (RR = 1.18, 95% CI:1.10-1.27) seemed higher in areas with high GDP per capita. The greater the population density, the higher the risk of BD (RR = 1.29, 95% CI: 1.23-1.36), enteric fever (RR = 1.12, 95% CI: 1.00-1.25), and HEV (RR = 1.15, 95% CI: 1.09-1.21). Among climate variables, higher temperature was associated with a higher risk of BD (RR = 1.32, 95% CI: 1.23-1.41), enteric fever (RR = 1.41, 95% CI: 1.33-1.50), and HFMD (RR = 1.22, 95% CI: 1.08-1.38), and with lower risk of HEV (RR = 0.83, 95% CI: 0.78-0.89). Precipitation was positively correlated with enteric fever (RR = 1.04, 95% CI: 1.00-1.08), HFMD (RR = 1.03, 95% CI: 1.00-1.06), and HEV (RR = 1.05, 95% CI: 1.03-1.08). Higher HFMD risk was also associated with increasing relative humidity (RR = 1.20, 95% CI: 1.16-1.24) and lower wind velocity (RR = 0.88, 95% CI: 0.84-0.92).

CONCLUSIONS

There was significant spatial clustering of IID incidence in Zhejiang Province from 2008 to 2021. Spatio-temporal patterns of IID risk could be largely explained by socioeconomic and meteorological factors. Preventive measures and enhanced monitoring should be taken in some high-risk counties in Hangzhou city and Ningbo city.

Gastrointestinal Infection in South African Children under the Age of 5 years: A Mini Review

Objective

To estimate gastroenteritis disease and its etiological agents in children under the age of 5 years living in South Africa.

Methods

A mini literature review of pertinent articles published in ScienceDirect, PubMed, GoogleScholar, and Scopus was conducted using search terms: "Gastroenteritis in children," "Gastroenteritis in the world," Gastroenteritis in South Africa," "Prevalence of gastroenteritis," "Epidemiological surveillance of gastroenteritis in the world," and "Causes of gastroenteritis".

Results

A total of 174 published articles were included in this mini review. In the last 20 years, the mortality rate resulting from diarrhea in children under the age of 5 years has declined and this is influenced by improved hygiene practices, awareness programs, an improved water and sanitation supply, and the availability of vaccines. More modern genomic amplification techniques were used to re-analyze stool specimens collected from children in eight low-resource settings in Asia, South America, and Africa reported improved sensitivity of pathogen detection to about 65%, that viruses were the main etiological agents in patients with diarrhea aged from 0 to 11 months but that Shigella, followed by sapovirus and enterotoxigenic Escherichia coli had a high incidence in children aged 12-24 months. In addition, co-infections were noted in nearly 10% of diarrhea cases, with rotavirus and Shigella being the main co-infecting agents together with adenovirus, enteropathogenic E. coli, Clostridium jejuni, or Clostridium coli.

Conclusions

This mini review outlines the epidemiology and trends relating to parasitic, viral, and bacterial agents responsible for gastroenteritis in children in South Africa. An increase in sequence-independent diagnostic approaches will improve the identification of pathogens to resolve undiagnosed cases of gastroenteritis. Emerging state and national surveillance systems should focus on improving the identification of gastrointestinal pathogens in children and the development of further vaccines against gastrointestinal pathogens.

Epidemiology and genetic diversity of norovirus GII genogroups among children in Hubei, China, 2017-2019

Norovirus (NoV) is an important cause of viral acute gastroenteritis (AGE). To gain insights into the epidemiological characteristics and genetic diversity of NoV among children in Hubei, 1216 stool samples from children (≤ 5 years) obtained under AGE surveillance from January 2017 to December 2019 were analyzed. The results showed that NoV was responsible for 14.64% of AGE cases, with the highest detection rate in children aged 7-12 months (19.76%). Statistically significant differences were found between male and female infection rates (χ2 ​= ​8.108, P ​= ​0.004). Genetic analysis of RdRp and VP1 sequences showed that NoV GII genotypes were GII.4 Sydney [P31] (34.35%), GII.3 [P12] (25.95%), GII.2 [P16] (22.90%), GII.4 Sydney [P16] (12.98%), GII.17 [P17] (2.29%), GII.6 [P7] and GII.3 [P16] (each at 0.76%). GII.17 [P17] variants were divided into the Kawasaki323-like lineage and the Kawasaki308-like lineage. A unique recombination event was detected between strains of GII.4 Sydney 2012 and GII.4 Sydney 2016. Significantly, all GII.P16 sequences associated with GII.4/GII.2 obtained in Hubei were correlated with novel GII.2 [P16] variants that re-emerged in Germany in 2016. Antigenic site analysis of complete VP1 sequences from all GII.4 variants from Hubei identified notable variable residues of antibody epitopes. Genotyping under continuous AGE surveillance and observation of the antigenic sites of VP1 are important monitoring strategies for emerging NoV strains.

A population-based survey of the prevalence of self-reported acute gastrointestinal illness in Zhejiang Province, China

Acute gastrointestinal illness (AGI) is a prevalent public health concern worldwide. This study investigated the magnitude, distribution and burden of self-reported AGI among residents of Zhejiang Province, China. A face-to-face household survey was conducted using a multi-stage stratified random sampling method in 10 counties in Zhejiang Province between July 2018 and June 2019. In total, 12,021 participants were recruited. The prevalence of AGI 28 days after standardization was 1.8% (95% confidence interval (CI), 1.6–2.1), with an incidence rate of 0.24 episodes of AGI per person-year and an estimated 14 million cases of AGI in Zhejiang Province. Univariate and multivariable analyses showed a higher AGI prevalence among people who performed housework and were unemployed in summer and autumn among respondents living in western or northern cities (p < 0.05). More than 50% of AGI cases were attributed to the consumption of contaminated food. The disease burden caused by AGI in Zhejiang Province was approximately 975 million Chinses yuan (CNY). These results indicated that the disease burden of AGI in Zhejiang Province should be addressed and highlights the need for an improved active surveillance system of foodborne diseases to assess the impact of AGI on society and health.

Physicochemical Parameters Affecting Norovirus Adhesion to Ready-To-Eat Foods

The adhesion of noroviruses to strawberry, turkey slices, ham, and cheddar cheese was studied using murine norovirus 1 (MNV-1) as a surrogate for human norovirus (NoV). Based on plaque assay, the recovery and adhesion of MNV-1 depended on the food type (turkey versus strawberry), pH of the initial suspension buffer (pH 4 versus pH 7), and food fat composition (C₈ versus C₁₈). Recovery of infectious particles from turkey was 68% compared to 9.4% from strawberry. On turkey, adhesion of MNV-1 was lower at pH 7 (pH of fecal matter), and virus particles adhered to this pH were recovered more easily (33,875 PFU) than at pH 4 (pH of vomitus). The presence of fat and the composition of fatty acids seemed to increase MNV-1 recovery and adherent viral particles recovered but did not affect adhesion (68% on fat-free turkey and regular turkey). Adherent MNV-1 particles recovered from stainless steel coated with saturated fatty acid (C₈, C₁₄, C₁₈) increased significantly with chain length (P < 0.05), but adhesion did not seem to change. Using liquid droplet contact angle to measure surface energy, it was deduced that hydrophobic interactions contribute considerably to the adhesion of MNV-1 to stainless steel, polyvinyl chloride, and high-density polyethylene. IMPORTANCE Ready-to-eat (RTE) foods are major vehicles of transmission of foodborne viral pathogens, including NoV. The high incidence of gastroenteritis caused by viruses is due largely to their persistence in the environment and adhesion to different kinds of surfaces in the food industry, including the foods themselves. Compared with bacteria, adhesion of viruses to surfaces is poorly understood. Better knowledge of the physicochemical parameters involved in the adhesion of NoV to ready-to-eat foods is essential to devising effective strategies for reducing the persistence and, thus, the transmission of this virus.

The online-to-offline (O2O) food delivery industry and its recent development in China

This paper offers a unique perspective about the development of the online-to-offline (O2O) food delivery industry from 2017 to 2019 in China. This study demonstrates the latest transformation and improvements of the O2O market that address some common problems in the early stages of the development of this raising industry in China. New strategies and regulations from the O2O platforms, food providers, and national and local governments are discussed. In our view, the mission of the O2O industry in general has shifted from pursuing enormous quantity to ensuring high quality. China’s O2O food delivery industry warrants further attention and studies as it grows and develops into the future. We suggest future studies to work on its economic, behavioral, and health impacts on population level as it encompasses both great risks and rewards.