Norovirus: A genus in the family CALICIVIRIDAE, associated with epidemic GASTROENTERITIS in humans. The type species, NORWALK VIRUS, contains multiple strains.Caliciviridae Infections: Virus diseases caused by CALICIVIRIDAE. They include HEPATITIS E; VESICULAR EXANTHEMA OF SWINE; acute respiratory infections in felines, rabbit hemorrhagic disease, and some cases of gastroenteritis in humans.Gastroenteritis: INFLAMMATION of any segment of the GASTROINTESTINAL TRACT from ESOPHAGUS to RECTUM. Causes of gastroenteritis are many including genetic, infection, HYPERSENSITIVITY, drug effects, and CANCER.Disease Outbreaks: Sudden increase in the incidence of a disease. The concept includes EPIDEMICS and PANDEMICS.Virus Inactivation: Inactivation of viruses by non-immune related techniques. They include extremes of pH, HEAT treatment, ultraviolet radiation, IONIZING RADIATION; DESICCATION; ANTISEPTICS; DISINFECTANTS; organic solvents, and DETERGENTS.Foodborne Diseases: Acute illnesses, usually affecting the GASTROINTESTINAL TRACT, brought on by consuming contaminated food or beverages. Most of these diseases are infectious, caused by a variety of bacteria, viruses, or parasites that can be foodborne. Sometimes the diseases are caused by harmful toxins from the microbes or other chemicals present in the food. Especially in the latter case, the condition is often called food poisoning.Sapovirus: A genus of the family CALICIVIRIDAE associated with worldwide sporadic outbreaks of GASTROENTERITIS in humans. The first recorded outbreak was in human infants in Sapporo, Japan in 1977. The genus is comprised of a single species, Sapporo virus, containing multiple strains.Feces: Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.Caliciviridae: A family of RNA viruses infecting a broad range of animals. Most individual species are restricted to their natural hosts. They possess a characteristic six-pointed starlike shape whose surfaces have cup-shaped (chalice) indentions. Transmission is by contaminated food, water, fomites, and occasionally aerosolization of secretions. Genera include LAGOVIRUS; NORWALK-LIKE VIRUSES; SAPPORO-LIKE VIRUSES; and VESIVIRUS.Blood Group Antigens: Sets of cell surface antigens located on BLOOD CELLS. They are usually membrane GLYCOPROTEINS or GLYCOLIPIDS that are antigenically distinguished by their carbohydrate moieties.Ostreidae: A family of marine mollusks in the class BIVALVIA, commonly known as oysters. They have a rough irregular shell closed by a single adductor muscle.Norwalk virus: The type species in the genus NOROVIRUS, first isolated in 1968 from the stools of school children in Norwalk, Ohio, who were suffering from GASTROENTERITIS. The virions are non-enveloped spherical particles containing a single protein. Multiple strains are named after the places where outbreaks have occurred.Capsid Proteins: Proteins that form the CAPSID of VIRUSES.Food Handling: Any aspect of the operations in the preparation, processing, transport, storage, packaging, wrapping, exposure for sale, service, or delivery of food.Calicivirus, Feline: A species of the genus VESIVIRUS infecting cats. Transmission occurs via air and mechanical contact.Disinfection: Rendering pathogens harmless through the use of heat, antiseptics, antibacterial agents, etc.Vaccines, Virosome: Vaccines using VIROSOMES as the antigen delivery system that stimulates the desired immune response.Food Contamination: The presence in food of harmful, unpalatable, or otherwise objectionable foreign substances, e.g. chemicals, microorganisms or diluents, before, during, or after processing or storage.RNA, Viral: Ribonucleic acid that makes up the genetic material of viruses.Lettuce: Any of the various plants of the genus Lactuca, especially L. sativa, cultivated for its edible leaves. (From American Heritage Dictionary, 2d ed)Shellfish: Aquatic invertebrates belonging to the phylum MOLLUSCA or the subphylum CRUSTACEA, and used as food.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Ships: Large vessels propelled by power or sail used for transportation on rivers, seas, oceans, or other navigable waters. Boats are smaller vessels propelled by oars, paddles, sail, or power; they may or may not have a deck.Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Reverse Transcriptase Polymerase Chain Reaction: A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.Food Microbiology: The presence of bacteria, viruses, and fungi in food and food products. This term is not restricted to pathogenic organisms: the presence of various non-pathogenic bacteria and fungi in cheeses and wines, for example, is included in this concept.Rotavirus: A genus of REOVIRIDAE, causing acute gastroenteritis in BIRDS and MAMMALS, including humans. Transmission is horizontal and by environmental contamination. Seven species (Rotaviruses A thru G) are recognized.Virosomes: Semi-synthetic complex derived from nucleic-acid free viral particles. They are essentially reconstituted viral coats, where the infectious nucleocapsid is replaced by a compound of choice. Virosomes retain their fusogenic activity and thus deliver the incorporated compound (antigens, drugs, genes) inside the target cell. They can be used for vaccines (VACCINES, VIROSOME), drug delivery, or gene transfer.Rotavirus Infections: Infection with any of the rotaviruses. Specific infections include human infantile diarrhea, neonatal calf diarrhea, and epidemic diarrhea of infant mice.