Search Results (123)

During the Brazilian summer, from 29 December 2024, to 6 March 2025, a large cluster of acute gastroenteritis (AGE) outbreaks was reported along the coast of São Paulo State, Brazil, peaking in January 2025. Overall, 55 outbreaks involving 755 cases were officially notified, while more than 76,000 medical consultations for AGE were recorded across the region during the same period. A total of 50 stool samples were analyzed by RT-qPCR for group A rotavirus (RVA) and norovirus (NoV). NoV was detected in 27 samples (54.0%), confirming it as the main etiological agent, while RVA was identified in one sample (2.0%). Among NoV-positive cases, genogroup II (GII) predominated (59.0%), followed by genogroup I (GI) (19.0%) and mixed infections (22.0%). Genomic sequencing successfully genotyped 23 strains (95.8%), revealing six distinct genotypes. The recombinant GII.17[P17] was predominant (48.0%), followed by GI.3[P3], GI.3[P13], GI.5[P5], GII.4 Sydney_2012[P16], GII.3[P30], as well as mixed infections. No enteric viruses were detected in drinking water. However, seawater samples showed high concentrations of NoV GI and GII (up to 10⁴ GC L⁻¹) at beaches unsuitable for bathing. Wastewater surveillance revealed high viral loads, particularly NoV GII (up to 10⁸ GC L⁻¹), consistent with reported cases. To our knowledge, this is the first report in Brazil of a NoV-associated AGE outbreak investigated through an integrated approach combining clinical, environmental, and epidemiological surveillance data. Findings highlight genotype diversity and reinforcing the importance of integrated surveillance. Full article

Norovirus is the leading cause of acute infectious gastroenteritis in the world and accounts for a significant proportion of outbreaks at the food-borne and person-to-person levels. Due to their low infectious dose, persistence in the environment, and broad genetic diversity, they can quickly spread and reappear in even the most diverse populations. This review integrates current knowledge on the epidemiology of noroviruses, genomic organization, structural biology, virus–host interactions, and replication mechanisms, with a focus on factors that determine virus evolution and strain dominance. Literature has been systematically searched in the PubMed and Scopus databases to incorporate recent experimental and epidemiological findings. Analysis of global surveillance data indicates ongoing genetic diversification of circulating strains, with periodic replacement of major variants, particularly the GII.4 lineage. Variability of the capsid and recognition of histo-blood Group Antigens strongly affects the host’s susceptibility, viral attachment and immune escape. The capsid consists of most of the viral protein complexes. The structural proteins VP1 and VP2 are responsible for determining the contours of the capsid and antigenic specificity. Non-structural proteins are responsible for coordinating the genome replication and the modification of host cell pathways to favor the production of the virus. Eliminating these gaps by means of integrated genomic surveillance and functional studies will provide insight into the evolution of norovirus and help to develop broadly effective vaccines and antiviral strategies. Full article

During Zambia’s 2023–2024 cholera outbreak, reliance on single-pathogen diagnostics risked overlooking co-circulating enteric pathogens. This study estimated the prevalence of rotavirus and described co-detected enteropathogens and rotavirus genotypes among patients admitted with suspected cholera. A sub-analysis was conducted on diarrhoeal stool specimens collected from patients who met the syndromic suspected cholera case definition. Samples were tested using the Bosphore^® Gastroenteritis Panel v2, a multiplex PCR enteric panel, to detect rotavirus and other gastrointestinal pathogens. Rotavirus-positive specimens with sufficient viral load were further genotyped by RT-PCR targeting of the VP7 and VP4 genes. Among 319 suspected cholera admissions, rotavirus was detected in 18 patients (5.6%; 95% CI 3.4–8.8%), predominantly in children aged <5 years (27.8%, 5/18) and 6–17 years (27.8%, 5/18). Co-infection was common, with 17/18 (94.4%) of rotavirus-positive samples showing co-infection with at least one additional enteric pathogen, most frequently Campylobacter. Genotyping was successful in five samples and revealed heterogenous circulating strains, including G1P[8], G2P[4], G3P[6], G12P[6], and G1P[6]. Rotavirus accounted for a modest proportion of suspected cholera admissions and was frequently detected in mixed enteric infections, underscoring the value of multi-pathogen diagnostics and continued molecular surveillance during outbreak response. Full article

Norovirus is the leading cause of acute gastroenteritis outbreaks worldwide. A total of 1859 norovirus outbreaks were reported from 2016 to 2022 in Beijing, China. GII.2[P16] was the predominant genotype during 2016–2021, and GII.3[P12] during 2021–2022. In the early stage of the COVID-19 epidemic (January to June of 2020), strict prevention and control measures were implemented, and only eight norovirus outbreaks were reported. Most norovirus outbreaks occurred in schools (95.6%, 1778). As the level of schooling rises, the scale of norovirus outbreaks also increases (median case numbers: 8 for kindergarten, 10 for primary school, 11 for secondary school, and 14 for college; p trend < 0.001), while the attack rate decreases (median attack rates were correspondingly 25.8%, 17.5%, 10.0%, and 8.8%; p trend < 0.001). Compared to outbreaks caused by person-to-person transmission, foodborne and waterborne outbreaks are larger in scale. Delayed outbreak response is also a risk factor for larger-scale outbreaks. Norovirus outbreaks have emerged as a significant concern for public health in Beijing. Persistent genotyping efforts are essential to facilitate early warning. Outbreaks in different locations or through different transmission routes require specific prevention and control measures. Full article

Background: Dengue infection (DI) is a mosquito-borne arboviral disease primarily transmitted by infected female Aedes mosquitoes. In Bangladesh, DI poses a substantial public health challenge with recurrent outbreaks and rising incidence rates. This systematic review assesses the epidemiological characteristics of dengue infection in Bangladesh, focusing on demographic, clinical, and geographic trends. Objectives: To analyze dengue prevalence, demographic distribution, clinical symptoms, and serotype patterns in Bangladesh, with an emphasis on urban–rural disparities, gender differences, and serotype evolution. Methods: A systematic search was conducted across PubMed, Scopus, Web of Science, and Global Health (Ovid) databases, reviewing studies published from 2000 to 2024. Following PRISMA guidelines, 25 studies meeting eligibility criteria were selected. Data extraction and quality assessment were independently performed by three reviewers, ensuring methodological rigor. Results: Dengue incidence was higher in urban areas, mainly affecting males aged 20–34, with dengue virus serotype 3 (DENV-3) as the dominant serotype. Fever, headache, and joint pain were the most common symptoms, while severe cases often presented with respiratory and hemorrhagic complications. Acute symptoms like dyspnea and dehydration spread rapidly in densely populated areas. In rural areas, dengue showed a more endemic pattern, with persistent symptoms such as gastroenteritis and muscle pain. Conclusion: Dengue is now firmly endemic in Bangladesh, with clear geographic, demographic, and clinical differences. The dominance of DENV-3 and its association with more severe illness highlight the need for targeted and context specific interventions. Control efforts should prioritize vector management, public education, and continuous surveillance in urban areas, while strengthening community surveillance and primary healthcare in rural settings. Further research on rural transmission and the clinical impact of DENV-3 is essential to guide effective and tailored dengue control strategies. Full article

Swine enteric coronaviruses (SECoVs), including transmissible gastroenteritis virus (TGEV), porcine epidemic diarrhea virus (PEDV), porcine deltacoronavirus (PDCoV), and swine acute diarrhea syndrome coronavirus (SADS-CoV), are major enteric pathogens causing severe diarrhea, dehydration, high neonatal mortality, and substantial global economic losses. Rapid viral evolution and recombination continually generate antigenically diverse variants that limit cross-protection and undermine vaccine efficacy, particularly for PEDV genogroup II strains that now dominate worldwide circulation. This review synthesizes current knowledge on epidemiology, diagnostic innovations, and emerging vaccine platforms, with emphasis on advances since 2022. Recent progress includes molecular surveillance tools, rapid point-of-care diagnostics, and next-generation vaccine technologies such as mRNA-based and virus-like particle platforms. However, significant knowledge gaps persist regarding viral evolution dynamics, co-infection synergies, and zoonotic spillover potential, particularly following documented human infections with PDCoV. Effective long-term control requires integrated genomic surveillance, strengthened farm-level biosecurity, rationally designed multivalent vaccines targeting conserved epitopes, and harmonized international surveillance systems to reduce outbreak risk and enhance pandemic preparedness at the human–animal interface. Full article

During the summer of 2023, a spontaneous disease outbreak occurred in intensively stocked hybrid catfish (♀ channel catfish, Ictalurus punctatus × ♂ blue catfish, I. furcatus) in earthen ponds on a commercial aquaculture farm in South Texas. The farmer reported 50 to 80 dead fish per pond daily for a month. The fish were market size (1.0 ± 0.3 kg on average), resulting in substantial economic losses. Fifteen moribund fish were submitted for laboratory examination. Grossly, the fish showed distended abdomens, erythematous fins, and inflamed vents. Autopsy demonstrated visceral congestion, distended gastrointestinal tracts, and serosanguineous peritoneal effusion. Bacterial cultures from the internal organs revealed homogeneous bacterial growth after incubation. Presumptive biochemical characterization of the isolated bacteria identified Plesiomonas shigelloides. Further molecular confirmation was achieved by species-specific PCR amplification and 16S-rRNA sequencing. Juvenile catfish were experimentally challenged with the recovered isolates to fulfill Koch’s postulates. Moreover, an antibiogram was performed to evaluate the susceptibility of the isolates to a panel of FDA-approved antimicrobials. P. shigelloides isolates were pathogenic to channel catfish and alarmingly multidrug-resistant. We report here, for the first time, P. shigelloides infection in Texas commercial catfish aquaculture, emphasizing its significance as an emerging enteric pathogen that is difficult to treat with FDA-approved antimicrobials. Full article

Norovirus (NoV) and sapovirus (SaV) are major viral pathogens causing acute gastroenteritis (AGE) in both children and adults in developed countries and are also responsible for large-scale outbreaks. However, in Quebec, Canada, there are limited and updated data with respect to the genotypes circulating and implicated in outbreaks, particularly for SaV. This study aimed to investigate the genetic diversity and genotype predominance of NoVs and SaVs associated with AGE outbreaks in Quebec, Canada. Confirmed NoV and SaV outbreaks from long-term care facilities and hospital settings between September 2011 and April 2016 were investigated (n = 252). NoVs and SaVs were genetically diverse: 21 RdRp-capsid combinations were identified, of which 10 are recombinants. NoV GII.4 New Orleans[P4 NewOrleans] was the predominant genotype from 2011 to 2013, and GII.4 Sydney[P31] was the predominant genotype from 2013 to 2015. In 2015–2016, no single genotype predominated; instead, GII.17[P17], GII.4 Sydney[P16], GII.4 Sydney[P31], and SaV GI.2 strains were co-circulating at similar frequencies. Notably, emerging global genotypes including GII.17[P17], GII.4 Sydney[P16], GII.2[P16], and GII.4 San Francisco[P31] were detected for the first time in Quebec. These findings may contribute to an enhanced understanding of NoV and SaV infection and spread, and to the development of candidate vaccines. Full article

Norovirus is the leading cause of acute gastroenteritis worldwide, responsible for up to 90% of viral gastroenteritis outbreaks and an estimated 10.6 billion USD in annual economic losses in the U.S. Despite its well-documented seasonality, wastewater surveillance in the Eastern Upper Peninsula of Michigan reveals persistent GI norovirus detection year-round, diverging from national clinical trends that consistently show far greater GII prevalence. To characterize norovirus dynamics in this region, 250 mL wastewater influent grab samples were collected once per week across 14 sites, concentrated using a PEG-based method, and analyzed via digital droplet PCR (ddPCR) for GI and GII concentrations. Across the study period, the rate of positive sites per month ranged from 57 to 100% for GI and 74 to 97% for GII, with mean positivity rates of 85.4% (GI) and 88.7% (GII), indicating that both genogroups were detected frequently at comparable levels. GI was more prevalent in winter and spring (December–May), whereas GII was more prevalent during spring and summer (March–August). Mean GI gene copies per 100 mL ranged from 12,898 (October) to 532,792 (February), while mean GII concentrations ranged from 29,806 (December) to 1,100,215 (May). These patterns contrast with national clinical data, where GI contributes to a small minority of reported norovirus cases. This study explores potential environmental and behavioral factors contributing to this regional pattern. GI norovirus demonstrates greater resistance to wastewater treatment and environmental stability, which may facilitate its persistence in the region. Additionally, congregate living settings, such as college campuses and correctional facilities, may contribute to sustained GI prevalence through foodborne transmission and asymptomatic viral shedding. Overall, these findings suggest that environmental and social factors influence norovirus seasonality and genogroup distribution in this region, underscoring the need for improved monitoring and expanded multi-site wastewater and epidemiological research to better understand norovirus persistence in similar communities. Full article

Listeria monocytogenes is a foodborne pathogen of significant concern. While it typically causes mild, self-limiting gastroenteritis, it poses a much higher threat to immunocompromised individuals and pregnant women, where it may lead to miscarriage. Numerous outbreaks have been linked to ready-to-eat foods. Although heat treatment is commonly used for microbial decontamination, it is unsuitable for fresh produce such as fruits and vegetables. Other physical (e.g., UV, gamma irradiation) and chemical (e.g., NaOCl, ozone) methods can compromise sensory qualities or face limited consumer acceptance. Photodynamic Inactivation (PDI) has emerged as a promising alternative, particularly when using natural photosensitizers. Because PDI efficacy depends on photosensitizer diffusion, there is a need to further explore how different and complex fruit surface structures may influence its performance. Three fruit models were therefore selected to represent distinct surface textures and were evaluated in situ: apples (smooth), strawberries (irregular), and kiwis (fuzzy and hairy surface). The influence of contamination order was also evaluated, as this factor is highly relevant to real-world supply-chain scenarios but has been largely overlooked in prior research. Additionally, the study investigated how the order of contamination affected the decontamination outcome. Sodium-magnesium-chlorophyllin (Na-Mg-Chl), an approved food additive (E140), was used as photosensitizer. Fruits were cut into 1 cm² squares and inoculated with L. monocytogenes. A 100 µM Na-Mg-Chl solution was applied either before or after bacterial inoculation. All samples were then illuminated using a 395 nm LED (radiant exposure 15 J/cm²). When L. monocytogenes was applied first, followed by the addition of Na-Mg-Chl, a 5.96 log reduction was observed in apples, a 5.71 log reduction in strawberries, and a 6.02 log reduction in kiwis. Conversely, when Na-Mg-Chl was applied prior to bacterial deposition, apples showed a 5.61 log reduction, strawberries demonstrated a 6.34 log reduction, and kiwis achieved the highest inactivation, at 6.74 log units. These results indicate that PDI consistently achieved substantial bacterial reductions across all fruit types, regardless of surface characteristics or application order. This supports PDI as a powerful method for fruit surface decontamination, reducing public health risks and economic losses while preserving product quality and consumer confidence. Full article

Given the increasing frequency of heat waves, it is likely that swimming in surface water not officially designated as swimming water (wild swimming) will become more popular. The goal of this exploratory case study was to determine the extent of wild swimming in the Vecht river basin in Germany and the Netherlands and to identify and minimize biological risks. Through several years of field observations, supplemented by data from key informants and online sources, we identified the number of visitors, their level of exposure to water, and the total number of water-contact-associated outbreaks. During the hot summers of 2018 to 2020, between 29,000 and 37,000 people a year sought cooling in the streams, rivers and canals of this watershed, into which 52 sewage treatment plants discharge. As a result, 85% of the wild swimmers in the area swam in surface waters that do not comply with the European Bathing Water Directive. Between 2016 and 2020, at least eight outbreaks of gastroenteritis potentially linked to wild swimming occurred in the region. Most outbreaks have been associated with waters containing the highest concentrations of sewage effluent. A total of 1201 people participated in activities linked to the outbreaks. Of those, at least 107 (11%), primarily children who had engaged in intensive water-based activities, became infected. Potential prevention strategies were assessed. Targeted awareness raising, promoting safe alternatives for water recreation, outbreak surveillance, and adaptation of prevention manuals, are expected to be relatively easy to apply, effective, socially acceptable and not very costly. Full article

Cholera remains a major public health challenge, and co-infections can complicate clinical outcomes. In a cross-sectional study, we investigated the prevalence and patterns of enteric co-infections during Zambia’s 2023–2024 cholera outbreak and evaluated their implications for disease severity. 240 suspected cholera patients were enrolled from five healthcare facilities in Lusaka. Stools were tested for 11 enteric pathogens using the Bosphore^® Gastroenteritis Panel Kit v2 on the QuantStudio 5 qPCR, with Vibrio cholerae confirmed by real-time PCR (quantitative PCR). Co-infections were highly prevalent, affecting 79.2% of participants. Campylobacter was the most frequently detected pathogen (70.0%), followed by Norovirus GI/GII (20.0%). Persons living with HIV were significantly more likely to present with co-infections than their counterparts (adjusted PR 1.27, 95% CI: 1.07–1.51; p = 0.008). Participants with confirmed V. cholerae + coinfections (N = 62) were less likely to developed moderate to severe disease compared to those with mono-infections (adjusted PR 0.59, 95% CI: 0.38–0.90; p = 0.014). These findings highlight the high prevalence and complexity of co-infections during cholera outbreaks, potentially contributing to antimicrobial resistance. They also highlight the need for targeted clinical management, particularly among persons living with HIV. Full article

Acute gastroenteritis (AGE) is a major cause of illness and death in children under five, especially in low- and middle-income countries, and rotavirus A (RVA) and norovirus are the leading viral agents. The present study aimed to describe the development of a commercial multiplex TaqMan-based RT-qPCR assay to detect those viruses to enhance surveillance and public health responses in Brazil. The assay validation involved optimizing primers and probes for multiplex RT-qPCR, assessing analytical sensitivity, and confirming specificity. A multicenter pilot study across Brazil’s AGE surveillance network assessed the assay’s performance. The IBMP NAT assay demonstrated high specificity and sensitivity for detecting RVA and norovirus GI and GII. No cross-reactivity was observed. LoD95 values were low: 18.6 (GI), 71.2 (GII), and 12.3 (RVA) copies/reaction. In 379 clinical samples, diagnostic sensitivity and specificity exceeded 96% for all targets. The assay showed strong reproducibility across operators and instruments. Stability tests confirmed consistent performance under freeze–thaw, transport, and storage conditions. Compared to in-house RT-qPCR, the IBMP NAT test yielded lower Ct values, indicating improved detection of low viral loads. The IBMP NAT Kit significantly advances molecular diagnostics, enabling rapid, sensitive, and reliable detection of RVA and norovirus in fecal specimens. It strengthens public health surveillance and supports timely responses to AGE outbreaks, helping reduce disease burden in vulnerable populations. Full article

Staphylococcus spp. present a dual role in cheese production as some species are pathogenic, while others bring beneficial characteristics. Coagulase-positive staphylococci (CoPS), particularly Staphylococcus aureus, are of concern due to their ability to produce enterotoxins linked to foodborne outbreaks. These toxins, encoded by staphylococcal enterotoxin (SE) genes, cause gastroenteritis, especially vomiting. Many members of the genus harbor a plethora of virulence genes and are able to form biofilms. The prevalence of antibiotic-resistant strains, including methicillin-resistant S. aureus (MRSA), complicates control. In contrast, some members of the coagulase-negative staphylococci (CoNS) group, such as Staphylococcus carnosus, Staphylococcus condimenti, Staphylococcus equorum, Staphylococcus piscifermentans, Staphylococcus succinus, and Staphylococcus xylosus, contribute to ripening, influencing flavor and texture. Some are even considered safe and studied for their ability to inhibit pathogens. Expression of enterotoxin genes in Staphylococcus, particularly S. aureus, is influenced by environmental factors and can be regulated by different mechanisms including quorum sensing. Understanding gene expression in conditions found during cheese production and ripening can help in formulating effective interventions. Risks posed by enterotoxin-producing Staphylococcus in cheese are evident, with numerous outbreaks reported worldwide. Moreover, several species present risks to both animal and human health. Effective control measures include adherence to microbiological criteria in foods, animal health monitoring, good manufacturing practices (GMP), temperature control, proper ripening conditions and hygiene. This review compiles and discusses existing knowledge on CoPS and CoNS in cheeses, providing a framework for evaluating their risks and benefits and guiding future studies in cheese microbiology. Full article

Campylobacter spp. remain among the most common pathogens causing acute diarrhea worldwide. Campylobacter jejuni and Campylobacter coli are the main species that cause gastroenteritis. Campylobacteriosis is a food-borne disease, although this Gram-negative bacterium may be transmitted via water-borne outbreaks as well as direct contact with animals, emphasizing its zoonotic potential. Campylobacterisosis does not usually require hospitalization. Antimicrobials are warranted only for patients with severe disease, as well as patients who are at risk for severe disease, such as the elderly, pregnant women or immunocompromised patients. Nonetheless, the irrational use of antibiotics in human and veterinary medicine enhances antimicrobial resistance (AMR). Resistance of Campylobacter spp. to fluoroquinolones, macrolides and tetracyclines is a significant concern to the scientific community. Point mutations, horizontal gene transfer and efflux pumps are the main mechanisms for the development and transmission of AMR in Campylobacter spp. Emerging evidence suggests that climate change may indirectly contribute to the spread of AMR in Campylobacter, particularly through its influence on bacterial ecology, transmission pathways and antibiotic use patterns. Higher temperatures and extreme weather events accelerate bacterial growth, amplify the transfer of AMR genes and magnify disease transmission, including drug-resistant infections. Horizontal gene transfer, especially in the context of biofilm formation, may further perplex the situation. Excessive farming and overuse of antibiotics as growth promoters in animals may also contribute to increased AMR rates. Climate change and AMR are interconnected and pose a significant threat to global public health. Multidisciplinary strategies mitigating both phenomena are crucial in order to contain the spread of Campylobacter-related AMR. The aim of this review is to describe the molecular mechanisms that result in AMR of Campylobacter spp. and underscore the association between climate change and Campylobacteriosis. Novel methods to mitigate Campylobacter-related AMR will also be discussed. Full article