Outbreak Of Gastroenteritis Research Articles

Molecular epidemiology of human sapovirus based on the surveillance of wastewater and patients with acute gastroenteritis in Osaka, Japan.

Molecular epidemiology of human sapovirus based on the surveillance of wastewater and patients with acute gastroenteritis in Osaka, Japan.

Mitigating norovirus spread on cruise ships: A model-based assessment of diagnostic timing and isolation.

Acute gastroenteritis outbreaks caused by noroviruses are a common public health issue on cruise ships. Understanding the main drivers of sustained outbreaks is critical for evaluating the effectiveness of preventive interventions such as the isolation of infected individuals. We analysed a line-list of 121 cases from a norovirus outbreak on a cruise visiting Mediterranean ports (cumulative incidence among passengers 9.7%). We used a Bayesian inference model to reconstruct likely transmission chains, taking into account different transmission settings and the isolation of cases after diagnosis. We then calibrated a branching process model to simulate alternative isolation scenarios and estimate their effectiveness in reducing transmission. Reconstructed transmission chains revealed a high heterogeneity in individual transmission, with 57% (95% CrI: 48%-65%) of secondary cases caused by 10% of infected individuals (here termed 'superspreaders'). Superspreaders exhibited longer diagnostic delays (mean 83hours, 95% CrI: 70-96hours) compared to other infectors (mean 47hours, 95% CrI: 44-50hours) and a halved frequency of vomiting and diarrhoea episodes. The 72-hour isolation protocol implemented during the outbreak averted 71% of potential cases compared to a no-intervention scenario, halving the effective reproduction number from 9.8 (95%CrI of the mean: 7.1-12.7) to 4.9 (95%CrI: 3.0-7.1). Reducing diagnostic delays further reduced the effective reproduction number, resulting in lower case numbers and probability of sustained outbreaks. Timely diagnosis and isolation have a remarkable impact on norovirus containment on cruise ship outbreaks. Targeted information campaigns encouraging passengers to seek immediate medical assistance upon gastrointestinal symptoms can significantly improve outbreak management.

First Case of Infective Endocarditis Caused by Vibrio metschnikovii: Clinico-Diagnostic Complexities and a Systematic Literature Review

Background: Non-cholera Vibrio species are rare waterborne pathogens that can cause severe infections. Among these, few cases of Vibrio metschnikovii infections have been reported, especially in the gastrointestinal tract, with no cardiac tissue involvement as a result. Following the PRISMA checklist, we conducted a literature review, and thirteen articles for twenty-two cases overall were included: seven cases of sepsis (in three cases, the echocardiographic results were negative), seven cases of pneumonia, two skin infections, eleven cases of diarrhoea, and a gastroenteritis outbreak. This report documents the expanding clinical spectrum and the role played by V. metschnikovii in infective endocarditis. Case report: A 28-year-old male patient was referred to the cardiac surgery unit for urgent mitral valve replacement due to suspicion of infective endocarditis. Microbiological tests yielded negative results. Following recovery and discharge with antimicrobial therapy for 6 weeks, the patient experienced prosthesis detachment, necessitating re-hospitalisation for an emergency valve replacement. Vibrio metschnikovii was identified on the prosthesis valve through PCR and successfully treated with ciprofloxacin. However, a spontaneous rupture of the ascending thoracic aorta led to a neurological injury. Discussion: This case represents the first case of valve infection caused by Vibrio metschnikovii, characterised by diagnostic and therapeutic challenges and the involvement of the great vessels. Also considered in this case, for a disease with a median age of 58 years (11–83) and a male-to-female ratio of 2.2, were one male neonate and six cases for whom neither sex nor age was indicated. Excluding gastrointestinal cases, the septic forms are associated with high morbidity, although the single case described involved a young and healthy subject. Risk factors for the pathogen or predisposing/pathological conditions for endocarditis did not emerge. The routes and the time of infection could not be determined, deepening the possibility of occupational exposure via the patient’s position as a boat worker. Poor sensitivity to third-generation cephalosporins has been reported in the literature: the absence of an antibiogram does not allow for a comparison, although resolution was achieved with ciprofloxacin. Conclusion: The rising global incidence of non-cholera Vibrio infections, driven by environmental changes, calls for urgent research into the factors behind their pathogenicity and infection routes. Diagnostic complexities have emerged together with clinical severity.

Incidence of Human Sapovirus Outbreaks in Beijing, China, 2014–2021: Predominance of Genotypes GII.3 and GI.2

The study aimed to analyze epidemiological, clinical, and genome characteristics of acute gastroenteritis (AGE) outbreaks caused by sapovirus in Beijing. Epidemiological and clinical characteristics of sapovirus detected by RT-qPCR were collected from AGE surveillance. Descriptive statistics were used for epidemiological analysis, and both genotype identification and sequence analysis were conducted on the VP1 regions, RNA-dependent RNA polymerase regions, and whole genomes. From 2014 to 2021, sapovirus was the second most common pathogen in AGE outbreaks, causing 216 outbreaks (6.85%) with peaks in 2017, 2019, and 2021. The predominant outbreaks occurred in kindergartens (76.39%, 165) and primary schools (18.98%, 41) within urban (62.96%, 136) and suburban (35.19%, 76) by person-to-person transmission (97.73%, 172). Outbreaks in outer suburbs lasted longer duration[median 7 days, IQR: 6–8)]. Comprehensive schools (21.62%, IQR: 10.00–35.00%) and kindergartens (18.18%, IQR: 13.51–22.72%) showed higher attack rates. Clinical symptoms included vomiting (97.27%, 1,462), diarrhea (18.44%, 277), fever (8.32%, 125), nausea (28.72%, 432), and abdominal pain (33.94%, 510). Vomiting prevalence was higher in children aged ≤5 years (96.94%, 983/1,014), while diarrhea prevalence was higher in those >5 years (31.29%, 153/489). Eight genotypes (GI.1–3, 5, 6; GII.1, 3, 5) were identified, and the predominant genotype changed from GII.3 (2016–2019) to GI.2 (2020–2021). Phylogenetic analysis revealed emerging clades in GII.3 and GI.2, with nucleotides and amino acids mutations confirmed by whole-genome sequencing. Therefore, sapovirus is a significant AGE pathogen in Beijing, China, warranting its inclusion in surveillance among sporadic outbreaks of AGE in China necessitating genotyping and whole-genome sequencing.

Correlation of Mutations in the hblA Gene with Bacillus cereus Disease Isolated from Loungwila, a Traditional Fermented Beverages in Republic of Congo

Bacillus cereus is a pathogenic bacterium recognized for triggering foodborne illnesses, particularly through its enterotoxins, which are linked to various gastroenteritis outbreaks. This study explores the relationship between mutations in the hblA gene, which encodes for the haemolysin BL toxin, and B. cereus strains isolated from Lougwila, a traditional fermented beverage in the Republic of Congo. A total of 145 B. cereus strains were obtained from Lougwila samples, and their hblA gene sequences were analyzed for mutations by using PCR, sequencing and in silico translation. In the hblA region 100-230, we identified deletion mutations of amino acids, as follows: HblA-S23∆KN, ∆YYE, ∆KEG, S28-∆KKQL, ∆QQNQ, and ∆ESD. Substitution mutations as follows: HblA-S23-A103K, N103R, S28-N222Q, Y223L, Y224E, K225S, Q226D, S52-Q169A, Q165Y, K212L S62-K112R, K114R, Q169A, Q170A, , S2-E174N, and Y224A. In the hblA region 250-330, we identified three substitution mutations in B. cereus S2, comprising: E290D, Q269L, and E265D. The results revealed a significant correlation between specific mutations in HblA 3D structures. This study underscores the need for further investigation into the genetic diversity of B. cereus strains in fermented foods, as well as the implementation of safety measures to mitigate foodborne outbreaks.

Role of post-harvest abiotic factors on interactions of Salmonella typhimurium with lettuce leaves (Lactuca sativa L. var crispa).

Role of post-harvest abiotic factors on interactions of Salmonella typhimurium with lettuce leaves (Lactuca sativa L. var crispa).

The outbreak of acute gastroenteritis caused by sapovirus at a school in Shenzhen, China, 2023.

Between February 6 and 8, 2023, an increasing number of students showed symptoms of vomiting in a school in Shenzhen, China. To identify the cause of this outbreak and curb disease spread on February 9, 2023, and an outbreak investigation including a case-control study was conducted. A structured questionnaire was used to collect the symptoms of all cases, a retrospective cohort study were conducted to examine the risk factors for diarrhea or vomiting. To find the contamination source, we investigated the environment all buildings in schools. Relative risk was presented and Chi-square test was performed. All the analyses were performed with OpenEpi software version 2.3.1 online. PCR was used to test stool specimens. This outbreak was caused by sapovirus, and lasted for 9 days. 70.9% of cases reported vomiting, 53.5% diarrhea, 38.4% bellyache, 14.0% feel nauseous, and 69.6% had diarrhea no more than twice. Eating food provided by the school or drinking water from direct-drinking machine was not associated with the acquisition of AGE based on univariate analysis. The students who had passed near a spot of vomit (<2.4 m) were more likely to get AGE with a relative risk of 5.09 (95%CI: 2.58, 10.04). The case number with AGE in classrooms using standard operating procedure for vomit cleanup is obviously lower than that in ones not handling vomit according to the standard procedure [relative risk (RR):0.34, 95%CI: 0.15, 0.77]. Sapovirus was the causative agent of this AGE outbreak, and airborne transmission was the primary route of infection. Prompt decontamination and the use of vomit bags significantly reduce the incidence of AGE while close contact with contaminated materials increases the risk of infection. These measures should be prioritized in public health strategies to prevent and control viral gastroenteritis outbreaks.

A dual enhancement strategy for ultrasensitive detection of norovirus based on catalytic hairpin assembly-assisted CRISPR/Cas12a sensing system.

Noroviruses are a leading cause of food-borne illnesses, responsible for over 50% of global gastroenteritis outbreaks. Whereas reverse transcriptase PCR (RT-PCR) and other nucleic acid amplification methods are crucial for norovirus detection, their reliance on specialized equipment highlights the urgent need for more accessible detection methods. Herein, we propose an isothermal cascade signal amplification assay that integrates catalytic hairpin assembly (CHA) and cluster regularly interspaced short palindromic repeats (CRISPR)/Cas12a for rapid and accurate detection of norovirus in food samples. By incorporating the advantages of CHA and CRISPR/Cas12a, the dual signal enhancement sensing strategy can achieve high sensitivity low to 14 fM within 70 min, and good specificity in adenovirus, human enterovirus, rotavirus, and other interfering agents. The proposed dual enhancement strategy for norovirus detection has satisfactory accuracy and acceptable recoveries in milk samples compared with RT-PCR assay, and holds promise for improving food safety monitoring, particularly in dairy products.

An outbreak of norovirus associated acute gastroenteritis in the Southern District of Kerala

A widespread acute gastroenteritis outbreak was reported in Alappuzha, Kerala, during the third week of June 2021. Symptoms such as vomiting and diarrhea have been observed in people in all age groups. There were no fatalities among those who were infected. A descriptive study performed to determine the epidemiological characteristics and etiology of the outbreak. A realstar Norovirus RT‒PCR kit was used to detect norovirus in the stool samples. A partial junction sequence of ORF1/ORF-2 was used for sequence analysis. A total of 770 cases of acute gastroenteritis from the same area were reported at a public health facility from June‒July 2021. Among the reported cases, children under 5 years of age were the most affected, with an attack rate of 10.3. Six out of the eleven stool samples referred to the National Institute of Virology, Kerala unit were positive for norovirus GII. The phylogenetic tree revealed that the Kerala strain is closely related to the Japan 2015 strain and has 99% homology with GII. The P17 type is a widely circulating strain in other countries. The study concluded that the outbreak was caused by norovirus GII. The virus may circulate locally in India and may be introduced into Kerala for the first time

Identification of Co-29, a 5-cyano-2-thiacetyl aromatic pyrimidinone, as a potential inhibitor targeting the RdRp of norovirus

BackgroundHuman norovirus (HNV) is the predominant pathogen causing outbreaks of acute gastroenteritis globally. Despite significant efforts to combat norovirus infections, there is currently no FDA approved vaccine or antiviral drug available. Consequently, the development of effective antiviral agents is of critical importance.Methods and resultsIn this study, a series of 41 5-cyano-2-thiacetyl aromatic pyrimidinone compounds were designed and synthesized. A cell viability-based screening for anti-murine norovirus (MNV) compounds was conducted, revealing that compound 29 (hereafter used as Co-29) exhibited antiviral activity against MNV. Co-29 demonstrated effective inhibition of MNVCW3 RNA replication, exhibiting an EC50 of 58.22 μM. An RdRp enzyme activity assay indicated that Co-29 directly inhibits RdRp activity to both MNV and HNV. Molecular docking studies suggested that Co-29 interacts with the palm region of RdRp via hydrogen bonding with specific residues, which are conserved in RdRps across MNV and HNV norovirus variants.ConclusionsIn conclusion, our study suggests that the newly synthesized Co-29 may serve as a potential antiviral candidate or lead compound for future studies.

Identification of a recombinant GII.13[P21] norovirus strain: molecular dynamic simulations indicate that gene mutations shifted its spectrum of binding to host receptor glycans.

Human norovirus is a pervasive pathogen that causes global outbreaks of viral gastroenteritis. Previous studies have suggested that histo-blood group antigens (HBGAs) can interact with human norovirus, facilitating its entry of host cells and significantly affecting its evolution. In this study, the complete genome sequence of recombinant GII.13[P21] norovirus from fecal samples was analyzed. Molecular dynamics simulations of GII.13 norovirus P proteins from 1978 to 2019 showed changes in their capacity to bind to HBGAs. Initially, GII.13 proteins bound A or B/H-type HBGAs, but subsequent mutations resulted in a loss of this binding capacity, favoring binding to the HBGA type I precursor (Lewis c) over A or B/H and Lewis antigens.

Report of two coinfections of human adenovirus and sapovirus in patients with acute gastroenteritis from China.

Coinfections involving multiple diarrheal viruses have gained increasing recognition as a significant cause of acute gastroenteritis in recent years. Understanding the genetic diversity and evolutionary relationships of these viruses is crucial for effective outbreak identification and tracking. To report two cases of HAdV and SaV coinfections and elucidate the genetic diversity and evolutionary patterns of these viruses through whole-genome sequencing (WGS) and phylogenetic analysis. A total of 873 diarrheal stool samples were collected from sentinel hospitals in Shenzhen, China, in 2021. The collected stool samples were identified using RT-PCR and positive samples were subjected to WGS on the NovaSeq platform. phylogenetic trees were constructed using MEGA to analyze genetic relationships. The sequencing results showed that both samples were human adenovirus type 41, which clustered in two distinct evolutionary clades. Additionally, we also retrieved the complete genome of sapovirus (GI.1 genotype) from the same sample. Phylogenetic analysis revealed that they were similar to previously reported strains, belonging to the clade predominating in China. This study reveals the genetic diversity of epidemic strains involved in coinfections of human adenovirus and sapovirus. The findings establish a groundwork for the identification and traces of acute gastroenteritis outbreaks.

A foodborne norovirus outbreak associated with six events and a single caterer, Canberra, November 2022.

An outbreak of gastrointestinal illness was investigated, affecting six events where attendees consumed food catered by a single catering business, in the Australian Capital Territory (ACT). Event attendees and the catering business were surveyed using tailored food questionnaires developed in REDCap and administered on-line. Descriptive analyses were conducted for all event attendees and employees of the business, and non-fatal productivity loss estimates calculated. Retrospective cohort studies were conducted for events that occurred on two specific days. A food safety inspection was undertaken of the catering business, and food and environmental samples were collected for microbiological analysis. Faecal specimens were collected from symptomatic event attendees. A total of 82.2% of event attendees (129/157) completed a survey, of whom 49.6% (64/129) reported gastrointestinal illness resulting in an estimated non-fatal productivity loss of AUD $23,700. Univariate analysis of data collected from events on 16 November identified that illness was significantly associated with consumption of vegetarian rice paper rolls (risk ratio [RR]: 1.6; 95% confidence interval [95% CI]: 1.0-3.0; p = 0.04). Multiple foods were significantly associated with illness from events that occurred on 17 November 2022. On multivariable analysis, vegetarian rice paper rolls were associated with illness on 16 November 2022 (RR: 1.7; 95% CI: 1.01-2.8; p = 0.046); however no individual food categories were significantly associated with illness on 17 November 2022. Seven faecal specimens were positive for norovirus. While no food handlers reported illness prior to the outbreak, one food handler reported that their child had had gastroenteritis in the preceding week. Environmental Health inspection of the catering business identified inadequate handwashing facilities. Microbiological testing of seven food samples produced two marginal results: coagulase positive Staphylococcus in a sandwich egg mix and a high standard plate count in the roast beef. This gastroenteritis outbreak was determined to be due to norovirus. The infection source was suspected to be an asymptomatic food handler and inadequate food handling controls allowing contamination of certain foods. This study demonstrates the importance of effective hand hygiene and food handling practices at all times, given that asymptomatic individuals can excrete and transmit norovirus and these outbreaks can be large and costly.

Evaluation and Application of the MIRA-qPCR Method for Rapid Detection of Norovirus Genogroup II in Shellfish.

Globally, norovirus has become the primary cause of outbreaks of acute gastroenteritis, and an increasing number of norovirus GII infections have been associated with shellfish. This highlights the urgent need to establish sensitive and rapid detection platforms for timely screening of contaminated shellfish to reduce the risk of virus transmission. To address this challenge, we developed a novel detection method combining multienzyme isothermal rapid amplification (MIRA) with qPCR, referred to as MIRA-qPCR, specifically targeting norovirus GII. It exhibited robust specificity, demonstrating no cross-reactivity with sapovirus, rotavirus, hepatitis A virus, Escherichia coli, Listeria monocytogenes, or Vibrio parahaemolyticus, and exhibited high sensitivity, detecting as low as 1.62 copies/μL for recombinant plasmid standards. Furthermore, MIRA-qPCR showed good linearity in the 1.62 × 101 to 1.62 × 107 copies/μL range, with an R2 > 0.90. MIRA-qPCR and qPCR assays were performed on 125 fresh shellfish samples; there was good consistency in the detection results, and the Kappa value was 0.90 (p < 0.001). The sensitivity and specificity of the MIRA-qPCR detection were 100.00% and 97.25%, respectively. The MIRA-qPCR technique provides a viable alternative for the rapid screening of norovirus GII-contaminated shellfish to guarantee food safety.

An MDR Salmonella Enteritidis sublineage associated with gastroenteritis outbreaks and invasive disease in China.

An MDR Salmonella Enteritidis sublineage associated with gastroenteritis outbreaks and invasive disease in China.

Footprints to findings: insight into causality of an acute gastroenteritis outbreak in a closed community

cases of acute gastroenteritis (AGE) within an urban community located in western Maharashtra. This investigation sought to identify the origin and causal agents of the outbreak, as well as to establish and implement measures to control its spread. Methods: A matched case-control study was conducted by taking 30 cases and 78 controls from that semi-urban residential area. Blood and stool culture samples of patients reporting to a primary health care facility were obtained using conventional culture techniques and polymerase chain reaction (PCR) kits. Epidemiological investigations comprised a review of surveillance data, filling of epidemiological case sheets, sanitary surveys, inspection of water supply and bacteriological surveillance of water and environmental engineering surveys. Results: The crude attack rate was reported to be 7%. Laboratory tests revealed multiple pathogens, including Pseudomonas, diarrheagenic E. coli, and Shigella. Environmental assessments highlighted issues such as rusted and leaky water pipes, sewage pipeline problems and insufficient chlorination of the water supply. Conclusions: A widespread outbreak of waterborne gastroenteritis occurred in this region due to contamination of drinking water. The contamination was caused by an improper connection between the sewage system and potable water pipelines. Recommended actions included repair of cross connections, improved treatment methods, adequate chlorination, regular inspections of the water supply and health education which significantly reduced the impact of outbreak.

Healthcare-Associated Gastroenteritis: Outbreak Report and Systematic Review of the Literature.

Healthcare-associated gastroenteritis continues to be associated with significant pediatric morbidity and mortality despite the introduction of rotavirus vaccines. Infection prevention (IP) measures are critical in mitigating outbreaks. We describe an outbreak of norovirus and effective IP strategies utilized and calculated the costs associated with the outbreak. To demonstrate the burden of these events, we conducted a systematic review of pediatric healthcare-associated gastroenteritis outbreaks since 1973 to describe changing epidemiologic trends. Twenty-four publications describing 27 outbreaks were included in the final analysis with 293 healthcare-associated cases. Rotavirus (14) and norovirus (7) outbreaks were most commonly described. Limitations include the retrospective nature of included reports, nonuniform data ascertainment and reporting among publications. Norovirus has replaced rotavirus as the most common etiology of healthcare-associated gastroenteritis outbreaks in North America, Europe, and Australia and New Zealand, since the introduction of rotavirus vaccines.

Norovirus GI.5 [P4]: first report of the rare norovirus recombinant variant in Northeastern Mexico and its global epidemiological context.

Norovirus is the primary cause of acute gastroenteritis outbreaks, considerably impacting children under 5years, followed by older adults and immunocompromised individuals. As an RNA virus, norovirus exhibits high genetic variability, driven by recombination events at the ORF1-ORF2 junction. This study reports the first detection of the rare norovirus GI.5 [P4] variant in Northeastern Mexico, identified in a single positive isolate (MTY0115; GenBank: PQ369661) from a sample group of 386 individuals, with a prevalence of 0.25%. Notably, norovirus GII was not detected. Phylogenetic analysis of the partial RdRp/VP1 region revealed clustering with global GI.5 [P4] sequences, revealing evolutionary relationships with isolates from Asia, Europe, and America. A recombination event was identified at position 5307 (breakpoint based on reference sequences of GI.5 [P5] and GI.4 [P4]) within ORF1, with genetic inheritance from a GI.5 [P5] isolate from Moscow, Russia, and a GI.4 [P4] isolate from France. Typing classification through sequencing of overlapping ORF1 and ORF2 regions is valuable for understanding genomic variations and their epidemiological impact on at-risk and non-risk populations.

Multi-Province Outbreak of Acute Gastroenteritis Linked to Potential Novel Lineage of GII.17 Norovirus in Argentina in 2024.

Noroviruses represent one of the leading causes of outbreaks and sporadic acute gastroenteritis (AGE) cases across all age groups. Although the GII.4 norovirus has been identified as the primary cause of most AGE outbreaks, the transient predominance of other genotypes has been reported globally. In this study, we describe a multi-province AGE outbreak caused by a potential new lineage of norovirus GII.17[P17], which has been recently detected at a high incidence in the United States and Europe. An amino acid analysis of the major viral capsid protein revealed several substitutions in the hypervariable region compared to strains circulating in the mid-2010s, which could play a key role in immune evasion. This is the first report of the detection of these viruses in the Southern Hemisphere, underscoring the importance of maintaining active genomic surveillance in the context of increasing numbers of acute gastroenteritis outbreaks.

Norovirus GII.17 gastroenteritis outbreak in a nursing home.

Norovirus GII.17 gastroenteritis outbreak in a nursing home.