Staphylococcal Enterotoxin A Induces Intestinal Barrier Dysfunction and Activates NLRP3 Inflammasome via NF-κB/MAPK Signaling Pathways in Mice.

Staphylococcal enterotoxin A (SEA), the toxin protein secreted by Staphylococcus aureus, can cause staphylococcal food poisoning outbreaks and seriously threaten global public health. However, little is known about the pathogenesis of SEA in staphylococcal foodborne diseases. In this study, the effect of SEA on intestinal barrier injury and NLRP3 inflammasome activation was investigated by exposing BALB/c mice to SEA with increasing doses and a potential toxic mechanism was elucidated. Our findings suggested that SEA exposure provoked villi injury and suppressed the expression of ZO-1 and occludin proteins, thereby inducing intestinal barrier dysfunction and small intestinal injury in mice. Concurrently, SEA significantly up-regulated the expression of NLRP3 inflammasome-associated proteins and triggered the mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B (NF-κB) signaling pathways in jejunum tissues. Notably, selective inhibitors of MAPKs and NF-κB p65 ameliorated the activation of NLRP3 inflammasome stimulated by SEA, which further indicated that SEA could activate NLRP3 inflammasome through NF-κB/MAPK pathways. In summary, SEA was first confirmed to induce intestinal barrier dysfunction and activate NLRP3 inflammasome via NF-κB/MAPK signaling pathways. These findings will contribute to a more comprehensive understanding of the pathogenesis of SEA and related drug-screening for the treatment and prevention of bacteriotoxin-caused foodborne diseases via targeting specific pathways.

Health and economic burden of foodborne zoonotic diseases in Amhara region, Ethiopia.

Diseases from food of animal origin are common health problems in Ethiopia. A cross-sectional study was carried out to estimate health and economic burden, and to identify demographic factors associated with community awareness of foodborne zoonotic diseases in Amhara region, Ethiopia. Data was collected from 435 households in three towns: Gondar, Lalibela and Debark. A retrospective data was also collected from health records in each town. The health burden due to zoonotic diseases was estimated at 0.2, 0.1 and 1.3 DALYs per household per year and at 73.2, 146.6 and 1,689.5 DALYs out of 100,000 populations per year in Gondar, Lalibela and Debark, respectively. The overall health burden due to foodborne zoonotic diseases (aggregated over the 435 households in the three towns) was estimated to be 89.9 DALYs per 100,000 populations per year. The economic impact of foodborne zoonotic diseases in the three towns of Amhara regional state was 278.98 Ethiopian Birr (ETB) (1ETB = 0.025 US Dollar) per household per year and 121,355.68 ETB per year. Costs of preventive measures followed by costs of patients' time made the highest contribution while costs of diagnosis made the lowest contribution to the total economic burden of foodborne zoonotic diseases. From a total of 435 respondents, 305 (70.1%) had known the presence of zoonotic diseases. Level of education, number of families in the house and income were highly associated with awareness of zoonosis. Although majority of respondents had known zoonotic diseases exists (70.1%) and disease can be acquired from animal source food (63.2%), the health and economic burden associated to foodborne zoonotic diseases are still high. Therefore, changing mindset and practical training aiming in controlling foodborne zoonotic diseases may be suggested to the community in the health improvement extension service.

Neurophysiological patterns of acute and post-acute foodborne botulism.

INTRODUCTION/AIMS: Neurophysiological patterns in patients with foodborne botulism are rarely described after the acute phase. We report data from a large Italian outbreak of botulism, with patients evaluated at different timepoints after poisoning. METHODS: Eighteen male patients (mean age 47 ± 8.4 y) underwent 22 clinical and neurophysiological evaluations (4 patients were re-evaluated). The resting compound muscle action potential (CMAP) amplitude, postexercise CMAP amplitude, CMAP change after high-frequency (50 Hz) repetitive nerve stimulation (HFRNS), and motor unit action potentials (MUAPs) were assessed in the acute (4-8 days after poisoning; 5 patients), early post-acute (32-39 days after poisoning; 5 patients), and late post-acute (66-80 days after poisoning; 12 patients) phases. RESULTS: In the acute, early post-acute, and late post-acute phases, respectively, reduced CMAP amplitudes were found in 100%, 20%, and 17% of patients; abnormal postexercise CMAP facilitation was observed in 100%, 40%, and 0% of patients; and pathological incremental responses to HFRNS were found in 80%, 50%, and 8% of patients. Baseline CMAP amplitudes, postexercise CMAP facilitation, and CMAP increases in response to HFRNS differed significantly between the acute and post-acute phases. Small MUAPs were found in 100% of patients in the acute and early post-acute phases and in 50% of patients in the late post-acute phase. DISCUSSION: The neurophysiological findings of foodborne botulism vary considerably according to the evaluation time point. In the post-acute phase, different neurophysiological techniques must be applied to support a diagnosis of botulism.

Evaluation of Electrocardiographic Parameters and the Presence of Interatrial Block in Patients with Mad Honey Intoxication.

Mad honey intoxication (MHI) is a food-induced clinical condition that usually presents with cardiovascular symptoms and can lead to life-threatening arrhythmias if not diagnosed and treated early. No data exist in the literature on the presence of interatrial block (IAB) after food intoxication. In our study, we sought to investigate atrioventricular electrocardiography (ECG) parameters and determine the frequency of IAB in patients with MHI. In total, 76 patients diagnosed with MHI were included in our retrospective study. Twelve-lead ECGs were performed and participants were divided into two groups according to the presence of IAB in the reference ECG. The P maximum (Pmax), P minimum (Pmin), P dispersion (Pdisp), T peak to T end (Tp-Te) interval and QT dispersion (QTdisp) values were compared between the two groups. IAB was detected in 28 (35.5%) of 76 MHI patients included in the final analysis. Pmax duration (122 ± 8; p < 0.001) and PD (69 ± 11; p < 0.001) were significantly higher in the IAB ( +) group. During regression analysis, Pmax [odds ratio (OR) 1.158, 95% confidence interval (CI) 1.036-1.294; p = 0.010] and Pd (OR 1.086, 95% CI 1.001-1.017; p = 0.046) were independently associated with IAB. Pmax and Pd area under the receiver operating characteristic curve values for IAB prediction were 0.926 (95% CI 0.841-1,000; p < 0.001) and 0.872 (95% CI 0.765-0.974; p < 0.001), respectively. ECG changes are common in patients presenting with MHI. These patients need to be followed up clinically in terms of progression to arrhythmic events that may occur in the future.

Report of the 1st International Electronic Conference on Toxins (IECT2021), 16-31 January 2021.

The 1st International Electronic Conference on Toxins (IECT2021) was successfully held online by https://sciforum [...].

Lathyrism and Socioeconomic Disparities: A Neglected Public Health Problem in Northeast Ethiopia.

Lathyrism is an incurable neurological disorder, resulting from excessive consumption of grass pea (Lathyrus sativus), which clinically manifests as paralysis of lower limbs. Because of the high production of grass peas, a large number of people are expected to be affected by the disease in Northeast Ethiopia. However, there is no comprehensive study that quantified the magnitude of the problem. Therefore, in this study, we determined the prevalence of lathyrism and socioeconomic disparities in Northeast Ethiopia. A community-based cross-sectional study was used which used a quantitative method of data collection from January to February 2019. Data were collected from a total of 2,307 inhabitants in the study area using structured questionnaires. Lathyrism cases were identified using a case definition of symmetrical spastic leg weakness, and subacute or insidious onset, with no sensory deficit, and with a history of grass pea consumption before and at the onset of paralysis. The majority (56.8%) of participants were male, and 34.7% were aged 45 years or older. Overall, the prevalence of lathyrism was 5.5%, and it was higher in males (7.9%) than in females (2.5%). Moreover, the prevalence was higher among farmers (7.0%) than merchants (0.3%), very poor economic status (7.2%) than very rich (1.1%), who produced (9.6%) grass pea than not produced (0.9%), and those who used clay pottery (6.2%) than metal (4.8%) for cooking. The prevalence of lathyrism in Northeast Ethiopia is remarkably high. Therefore, we recommend lathyrism to be among the list of reportable health problems and incorporated in the national routine surveillance system.

The Food Poisoning Toxins of Bacillus cereus.

Bacillus cereus is a ubiquitous soil bacterium responsible for two types of food-associated gastrointestinal diseases. While the emetic type, a food intoxication, manifests in nausea and vomiting, food infections with enteropathogenic strains cause diarrhea and abdominal pain. Causative toxins are the cyclic dodecadepsipeptide cereulide, and the proteinaceous enterotoxins hemolysin BL (Hbl), nonhemolytic enterotoxin (Nhe) and cytotoxin K (CytK), respectively. This review covers the current knowledge on distribution and genetic organization of the toxin genes, as well as mechanisms of enterotoxin gene regulation and toxin secretion. In this context, the exceptionally high variability of toxin production between single strains is highlighted. In addition, the mode of action of the pore-forming enterotoxins and their effect on target cells is described in detail. The main focus of this review are the two tripartite enterotoxin complexes Hbl and Nhe, but the latest findings on cereulide and CytK are also presented, as well as methods for toxin detection, and the contribution of further putative virulence factors to the diarrheal disease.

Fulminant Bacillus cereus food poisoning with fatal multi-organ failure.

This case represents a rare fulminant course of fried-rice associated food poisoning in an immunocompetent person due to pre-formed exotoxin produced by Bacillus cereus, with severe manifestations of sepsis, including multi-organ (hepatic, renal, cardiac, respiratory and neurological) failure, shock, metabolic acidosis, rhabdomyolysis and coagulopathy. Despite maximal supportive measures (continuous renal replacement therapy, plasmapheresis, N-acetylcysteine infusion and blood products, and broad-spectrum antimicrobials) and input from a multidisciplinary team (consisting of infectious diseases, intensive care, gastroenterology, surgery, toxicology, immunology and haematology), mortality resulted. This case is the first to use whole genome sequencing techniques to confirm the toxigenic potential of B. cereus It has important implications for food preparation and storage, particularly given its occurrence in home isolation during the COVID-19 pandemic.

[Scombroid food poisoning among hospital personnel]. / Scombroïde-intoxicatie onder ziekenhuispersoneel.

BACKGROUND: Scombroid food poisoning is caused by eating fish with a high concentration of histamine. Histamine is converted from histidine in fish of the Scombroidea family if it is not stored at a sufficiently low temperature. The clinical picture resembles an allergic reaction. CASE DESCRIPTION: Twenty-one of our hospital personnel went to the ER, mostly reporting flushing, headache, palpitations and gastro-intestinal symptoms. They had all eaten tuna salad in the staff canteen. The symptoms appeared to be caused by scombroid food poisoning. CONCLUSION: As a result of early recognition of the clinical picture and prompt crisis management we were able to prevent the outbreak spreading further.

Aspectos actuales de la listeriosis / Current aspects of listeriosis

La importancia de la listeriosis no está suficientemente reconocida. Su incidencia general se muestra estable en los últimos años, pero con una tendencia al alza en mayores de 65 años, también en mortalidad. La listeriosis es una enfermedad transmitida por alimentos que ocurre generalmente en forma de casos esporádicos; sin embargo, las nuevas técnicas de tipificación molecular han puesto de manifiesto la existencia de brotes epidémicos no sospechados con anterioridad. La enfermedad presenta un periodo de incubación variable y relacionado con la presentación clínica. La bacteriemia y la neurolisteriosis son las formas clínicas predominantes, aunque en la actualidad el principal interés se focaliza en el manejo de las infecciones focales y las asociadas a dispositivos protésicos. La listeriosis es un problema significativo para la industria alimentaria, y muchos países han introducido legislación para controlar la incidencia de la enfermedad

The importance of listeriosis is not sufficiently recognised. The general incidence of infection has been stable in recent years, but with an upward trend in people over 65, also in mortality. Listeriosis is a foodborne disease that generally occurs in the form of sporadic cases; however, new molecular typing techniques have revealed the existence of epidemic outbreaks not previously suspected. The disease has a variable incubation period, which is related to the clinical presentation. Bacteraemia and neurolisteriosis are the predominant clinical forms, although at present, the main interest is focused on the management of focal infections and those associated with prosthetic devices. Listeriosis is a significant problem for the food industry, and many countries have introduced legislation to control the incidence of the disease

The DH31/CGRP enteroendocrine peptide triggers intestinal contractions favoring the elimination of opportunistic bacteria.

The digestive tract is the first organ affected by the ingestion of foodborne bacteria. While commensal bacteria become resident, opportunistic or virulent bacteria are eliminated from the gut by the local innate immune system. Here we characterize a new mechanism of defense, independent of the immune system, in Drosophila melanogaster. We observed strong contractions of longitudinal visceral muscle fibers for the first 2 hours following bacterial ingestion. We showed that these visceral muscle contractions are induced by immune reactive oxygen species (ROS) that accumulate in the lumen and depend on the ROS-sensing TRPA1 receptor. We then demonstrate that both ROS and TRPA1 are required in a subset of anterior enteroendocrine cells for the release of the DH31 neuropeptide which activates its receptor in the neighboring visceral muscles. The resulting contractions of the visceral muscles favors quick expulsion of the bacteria, limiting their presence in the gut. Our results unveil a precocious mechanism of defense against ingested opportunistic bacteria, whether they are Gram-positive like Bacillus thuringiensis or Gram-negative like Erwinia carotovora carotovora. Finally, we found that the human homolog of DH31, CGRP, has a conserved function in Drosophila.

[Applications of simulated gastro-intestinal model in foodborne pathogens: tolerance and pathogenesis].

We evaluated the tolerance and pathogenesis of foodborne pathogens with a simulated gastro-intestinal tract model that simulates the chemical, physical and biological effects of human digestion process under laboratory conditions. This could be used to study the tolerance, pathogenesis, gut microbiota interaction and vaccine development of foodborne pathogens, so as to contribute to control and treatment of foodborne pathogens. This review introduces the applications of simulated gastro-intestinal tract model tp evaluate foodborne pathogens, which includes in-vitro static gastro-intestinal model, in-vitro dynamic gastro-intestinal model, conventional animal model and humanized animal model. And the concepts and characteristics of all models are described in detail. Also, the shortcomings of existing models are analyzed, and improvements of artificial gastro-intestinal tract model are prospected. In conclusion, this review could provide comprehensive data for promoting the progress of studying tolerance and pathogenesis of foodborne pathogens.

Study of Glucose-6-Phosphate Dehydrogenase Deficiency: 5 Years Retrospective Egyptian Study.

BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzyme deficiency worldwide that causes a spectrum of diseases including neonatal hyperbilirubinemia, acute and chronic hemolysis after exposure to oxidative stress. AIM OF THE WORK: This five years retrospective study was carried out to study the demographic, clinical and laboratory data of 1000 patients with G6PD deficiency anemia registered in Hematology Unit, Pediatric Department, Tanta University Hospital. PATIENTS AND METHODS: Data were collected from patient's files, from November 2011 to November 2016, using the pre-designed questionnaires to obtain the complete history, clinical presentation and laboratory investigations including the complete blood count, red blood cells morphology, liver and renal functions and quantitative assay of G6PD enzyme activity by spectrophotometric method. RESULTS: Males were more commonly affected than females (932 males versus 68 females). The highest prevalence of hemolytic crisis in G6PD deficiency patients was found within the age group of 1-3 years (920 patients; 92%) with mean age of the first presentation of 22.8±15.54 months. Patients presented mainly with pallor (1000 patients; 100%), dark red urine (896 patients; 89.6%) and jaundice (878 patients; 87.8%) after 24-72 hours of exposure to the precipitating factors (mean: 36±17.73 hours). Diets were the most common precipitating factor of hemolysis in patients with G6PD deficiency (834 patients; 83.4% of studied cases) especially fava beans (326 patients; 32.6%) and falafel (194 patients; 19.4%) which were the most common precipitating food products causing hemolysis followed by chick pea (108 patients; 10.8%), broad bean (76 patients; 7.6%), green pea (44 patients; 4.4%), pea nuts (38 patients; 3.8%), lentil (28 patients; 2.8%), and lastly black eyed peas (20 patients; 2 %). Infections were the 2nd most common cause of hemolysis (124 patients; 12.4%) including pneumonia (34 patients; 3.4%), tonsillitis (32 patients; 3.2%), typhoid fever (28 patients; 2.8%), hepatitis A (18 patients; 1.8%) and urinary tract infection (12 patients; 1.2%). Drugs were the least common cause of hemolysis (42 patients; 4.2%) including diclofenac sodium (24 patients; 2.4%), ibuprofen (8 patients; 0.8%), acetylsalicylic acid (4 patients; 0.4%), co-trimoxazole (4 patients; 0.4%) and nitrofurantion (2 patients; 0.2%). There was normocytic normochromic anemia with reticulocytosis and Heinz bodies in pre-transfusion complete blood picture in all studied cases. G6PD assay show marked decrease in enzyme level at time of presentation in all cases with the commonest G6PD enzyme level of 3-4 U/gm Hb (592 patients; 59.2%). CONCLUSION AND RECOMMENDATIONS: G6PD deficiency anemia presented mainly with pallor, dark red urine and jaundice after exposure to certain diets, drugs and diseases and therefore patients with G6PD deficiency should avoid exposure to these precipitating factors of hemolysis. We can also recommend large neonatal screening programs to detect cases of G6PD deficiency before the occurrence of acute hemolysis and molecular studies to detect G6PD enzyme variant in Egypt.

Oral administration of oxalate-enriched spinach extract as an improved methodology for the induction of dietary hyperoxaluric nephrocalcinosis in experimental rats.

Experimental induction of hyperoxaluria by ethylene glycol (EG) administration is disapproved as it causes metabolic acidosis while the oral administration of chemically synthesized potassium oxalate (KOx) diet does not mimic our natural system. Since existing models comprise limitations, this study is aimed to develop an improved model for the induction of dietary hyperoxaluria, and nephrocalcinosis in experimental rats by administration of naturally available oxalate rich diet. Male albino Wistar rats were divided into five groups. Group I, control; group II rats received 0.75% EG, group III rats fed with 5% KOx diet and group IV and V rats were administered with spinach extract of 250 and 500 mg soluble oxalate/day respectively, for 28 d. Urine and serum biochemistry were analyzed. After the experimental period, rats were sacrificed, liver and kidney tissue homogenates were used for antioxidant and lipid peroxidation assay. Relative change in expression of kidney injury molecule-1 (KIM-1) and crystal modulators genes in kidney tissues were evaluated. Tissue damage was assessed by histology studies of liver and kidney. Experimental group rats developed hyperoxaluria and crystalluria. Urine parameters, serum biochemistry, antioxidant profile, lipid peroxidation levels and gene expression analysis of experimental group II and III rats reflected acute kidney damage compared to group V rats. Histopathology results showed moderate hyperplasia in liver and severe interstitial inflammation in kidneys of group II and III than group V rats. Ingestion of naturally available oxalate enriched spinach extract successfully induced dietary hyperoxaluria and nephrocalcinosis in rats with minimal kidney damage.

Unresolving Pneumonia with Pleural effusion: Pulmonary Paragonimiasis.

Paragonimiasis is a zoonosis caused by many species of Paragonimus commonly P. westermani. Human get infected by eating raw, salted, pickled, smoked, partially cooked crustaceans (crayfish or crabs). Clinical manifestations ranges from non-specific symptoms like pain abdomen, diarrhea, urticarial rashes, fever to pleuropulmonary symptoms like cough, hemoptysis, chest pain and dyspnea. A 48 years, female presented at TUTH emergency with fever on and off for nine months, cough and shortness of breath for three months, lethargy, malaise and urticaria with history of raw crab intake one month prior to the onset of symptoms. Blood and pleural fluid analysis revealed raised total counts with eosinophilia and x-ray showed bilateral infiltration of lower lobes with pleural effusion. Diagnosis was confirmed by microscopic examination of sputum for Paragonimus. She responded well to Praziquantel. Pulmonary paragonimiasis must be considered in the differential diagnosis of unresolving pneumonia and unexplained hypereosinophilia.

Association of renal function and symptoms with mortality in star fruit (Averrhoa carambola) intoxication.

BACKGROUND: Star fruit (SF) is a commonly available fruit produced and eaten in tropical and subtropical countries. Since 1993, various reports have described neurotoxicity after eating SF, but this clinical condition remains unfamiliar. We aimed to describe this clinical entity, the role of renal dysfunction in this disorder, treatment strategies, and prognosis of patients with SF intoxication. METHODS: We conducted a search of PubMed and Google Scholar databases from 1993 to 2016. We included reports describing patients with a clear history of SF ingestion with acute symptoms. We described the demographic characteristics, reported SF intake, treatments used, and outcomes. RESULTS: We reviewed totally 126 patients (male:female = 1.5:1) from 33 articles with mean age 54.4 ± 11 (range: 30-84). The most common symptom was hiccups (65%), whereas confusion and seizure were the most common symptoms associated with mortality (42% and 61%, respectively). Pre-intoxication renal function also affected mortality. While there was no mortality in patients with normal renal function (NRF), the mortality of patients among reported cases with chronic renal insufficiency and end-stage renal disease undergoing dialysis were 36% and 27%, respectively. With the inclusion of patients reported to have NRF, the overall mortality was 24%. Consistently, the number of SF consumed was substantially higher in the patients with NRF than those with renal functional impairment. The most common treatment strategy was hemodialysis (59%). CONCLUSIONS: Patients with impaired renal function were at higher risks of SF intoxication. Severe neurologic symptoms mandate immediate medical intervention because of the association between their occurrence and high mortalities. Toxin removal through dialysis, rather than symptomatic relief, seems to be beneficial to patient survival. Early and continuous dialysis appears to alleviate severe symptoms and prevent symptom rebounds.

Review article: hepatitis E-a concise review of virology, epidemiology, clinical presentation and therapy.

BACKGROUND: Hepatitis E virus (HEV) is a leading cause of acute icteric hepatitis and acute liver failure in the developing world. During the last decade, there has been increasing recognition of autochthonous (locally acquired) HEV infection in developed countries. Chronic HEV infection is now recognised, and in transplant recipients this may lead to cirrhosis and organ failure. AIM: To detail current understanding of the molecular biology of HEV, diagnostic and therapeutic strategies and propose future directions for basic science and clinical research. METHODS: PubMed was searched for English language articles using the key words "hepatitis E", "viral hepatitis", "autochthonous infection", "antiviral therapy", "liver transplantation", "acute", "chronic", "HEV", "genotype", "transmission" "food-borne", "transfusion". Additional relevant publications were identified from article reference lists. RESULTS: There has been increasing recognition of autochthonous HEV infection in Western countries, mainly associated with genotype 3. Chronic HEV infection has been recognised since 2008, and in transplant recipients this may lead to cirrhosis and organ failure. Modes of transmission include food-borne transmission, transfusion of blood products and solid organ transplantation. Ribavirin therapy is used to treat patients with chronic HEV infection, but new therapies are required as there have been reports of treatment failure with ribavirin. CONCLUSIONS: Autochthonous HEV infection is a clinical issue with increasing burden. Future work should focus on increasing awareness of HEV infection in the developed world, emphasising the need for clinicians to have a low threshold for HEV testing, particularly in immunosuppressed patients. Patients at potential risk of chronic HEV infection must also be educated and given advice regarding prevention of infection.

Cyanide and the human brain: perspectives from a model of food (cassava) poisoning.

Threats by fundamentalist leaders to use chemical weapons have resulted in renewed interest in cyanide toxicity. Relevant insights may be gained from studies on cyanide mass intoxication in populations relying on cyanogenic cassava as the main source of food. In these populations, sublethal concentrations (up to 80 µmol/l) of cyanide in the blood are commonplace and lead to signs of acute toxicity. Long-term toxicity signs include a distinct and irreversible spastic paralysis, known as konzo, and cognition deficits, mainly in sequential processing (visual-spatial analysis) domains. Toxic culprits include cyanide (mitochondrial toxicant), thiocyanate (AMPA-receptor chaotropic cyanide metabolite), cyanate (protein-carbamoylating cyanide metabolite), and 2-iminothiazolidine-4-carboxylic acid (seizure inducer). Factors of susceptibility include younger age, female gender, protein-deficient diet, and, possibly, the gut functional metagenome. The existence of uniquely exposed and neurologically affected populations offers invaluable research opportunities to develop a comprehensive understanding of cyanide toxicity and test or validate point-of-care diagnostic tools and treatment options to be included in preparedness kits in response to cyanide-related threats.

Foodborne viral infections.

PURPOSE OF REVIEW: The aim of the study was to provide an update on foodborne viral infections describing illness burden, the main aetiological agents (enteric viruses, hepatitis viruses and emerging and zoonotic viruses) and advances in virus detection in foods. RECENT FINDINGS: Norovirus (NoV) is the most common viral foodborne pathogen globally (125 million cases and 35 000 deaths). The role of the asymptomatic food handlers in contributing to NoV outbreaks is becoming increasingly clear, with up to one-quarter of outbreaks attributable to them. Handwashing with soap and water remains the best method for removing NoV from fingers. Risk assessment for transmission of emerging viruses through the food chain should include consideration of all means by which food could post a hazard, that is not just consumption. New technologies have demonstrated the widespread nature of viral contamination in the food chain, but this does not necessarily correlate with the risk of disease. Finally, understanding people's knowledge and behaviour is just as important as understanding virus characteristics and epidemiology when assessing risks of foodborne transmission. SUMMARY: The predominant viruses transmitted through food tend to be those for which humans are the natural hosts, so that effective control measures need to prevent exposure of foods to human faeces.