Immunity: Nonsusceptibility to the invasive or pathogenic effects of foreign microorganisms or to the toxic effect of antigenic substances.Immunity, Innate: The capacity of a normal organism to remain unaffected by microorganisms and their toxins. It results from the presence of naturally occurring ANTI-INFECTIVE AGENTS, constitutional factors such as BODY TEMPERATURE and immediate acting immune cells such as NATURAL KILLER CELLS.Immunity, Cellular: Manifestations of the immune response which are mediated by antigen-sensitized T-lymphocytes via lymphokines or direct cytotoxicity. This takes place in the absence of circulating antibody or where antibody plays a subordinate role.Immunity, Herd: The non-susceptibility to infection of a large group of individuals in a population. A variety of factors can be responsible for herd immunity and this gives rise to the different definitions used in the literature. Most commonly, herd immunity refers to the case when, if most of the population is immune, infection of a single individual will not cause an epidemic. Also, in such immunized populations, susceptible individuals are not likely to become infected. Herd immunity can also refer to the case when unprotected individuals fail to contract a disease because the infecting organism has been banished from the population.Synaptic Transmission: The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.Disease Transmission, Infectious: The transmission of infectious disease or pathogens. When transmission is within the same species, the mode can be horizontal or vertical (INFECTIOUS DISEASE TRANSMISSION, VERTICAL).Cattle Diseases: Diseases of domestic cattle of the genus Bos. It includes diseases of cows, yaks, and zebus.Infectious Disease Transmission, Vertical: The transmission of infectious disease or pathogens from one generation to another. It includes transmission in utero or intrapartum by exposure to blood and secretions, and postpartum exposure via breastfeeding.DairyingAdaptive Immunity: Protection from an infectious disease agent that is mediated by B- and T- LYMPHOCYTES following exposure to specific antigen, and characterized by IMMUNOLOGIC MEMORY. It can result from either previous infection with that agent or vaccination (IMMUNITY, ACTIVE), or transfer of antibody or lymphocytes from an immune donor (IMMUNIZATION, PASSIVE).Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Immunity, Mucosal: Nonsusceptibility to the pathogenic effects of foreign microorganisms or antigenic substances as a result of antibody secretions of the mucous membranes. Mucosal epithelia in the gastrointestinal, respiratory, and reproductive tracts produce a form of IgA (IMMUNOGLOBULIN A, SECRETORY) that serves to protect these ports of entry into the body.Animal Husbandry: The science of breeding, feeding and care of domestic animals; includes housing and nutrition.Microscopy, Electron, Transmission: Electron microscopy in which the ELECTRONS or their reaction products that pass down through the specimen are imaged below the plane of the specimen.Immunity, Humoral: Antibody-mediated immune response. Humoral immunity is brought about by ANTIBODY FORMATION, resulting from TH2 CELLS activating B-LYMPHOCYTES, followed by COMPLEMENT ACTIVATION.Swine Diseases: Diseases of domestic swine and of the wild boar of the genus Sus.Plant Immunity: The inherent or induced capacity of plants to withstand or ward off biological attack by pathogens.Immunity, Maternally-Acquired: Resistance to a disease-causing agent induced by the introduction of maternal immunity into the fetus by transplacental transfer or into the neonate through colostrum and milk.Disease Outbreaks: Sudden increase in the incidence of a disease. The concept includes EPIDEMICS and PANDEMICS.Milk: The white liquid secreted by the mammary glands. It contains proteins, sugar, lipids, vitamins, and minerals.Antibodies, Viral: Immunoglobulins produced in response to VIRAL ANTIGENS.Mice, Inbred C57BLInsect Vectors: Insects that transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.Swine: Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).Vaccination: Administration of vaccines to stimulate the host's immune response. This includes any preparation intended for active immunological prophylaxis.Mastitis, Bovine: INFLAMMATION of the UDDER in cows.Mice, Inbred BALB CHIV Infections: Includes the spectrum of human immunodeficiency virus infections that range from asymptomatic seropositivity, thru AIDS-related complex (ARC), to acquired immunodeficiency syndrome (AIDS).Seroepidemiologic Studies: EPIDEMIOLOGIC STUDIES based on the detection through serological testing of characteristic change in the serum level of specific ANTIBODIES. Latent subclinical infections and carrier states can thus be detected in addition to clinically overt cases.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Microscopy, Electron, Scanning Transmission: A type of TRANSMISSION ELECTRON MICROSCOPY in which the object is examined directly by an extremely narrow electron beam scanning the specimen point-by-point and using the reactions of the electrons that are transmitted through the specimen to create the image. It should not be confused with SCANNING ELECTRON MICROSCOPY.Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Disease Reservoirs: Animate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (DISEASE VECTORS) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks.Enzyme-Linked Immunosorbent Assay: An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.Abortion, Veterinary: Premature expulsion of the FETUS in animals.Pregnancy Complications, Infectious: The co-occurrence of pregnancy and an INFECTION. The infection may precede or follow FERTILIZATION.Seasons: Divisions of the year according to some regularly recurrent phenomena usually astronomical or climatic. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Tuberculosis, Bovine: An infection of cattle caused by MYCOBACTERIUM BOVIS. It is transmissible to man and other animals.Dendritic Cells: Specialized cells of the hematopoietic system that have branch-like extensions. They are found throughout the lymphatic system, and in non-lymphoid tissues such as SKIN and the epithelia of the intestinal, respiratory, and reproductive tracts. They trap and process ANTIGENS, and present them to T-CELLS, thereby stimulating CELL-MEDIATED IMMUNITY. They are different from the non-hematopoietic FOLLICULAR DENDRITIC CELLS, which have a similar morphology and immune system function, but with respect to humoral immunity (ANTIBODY PRODUCTION).Malaria: A protozoan disease caused in humans by four species of the PLASMODIUM genus: PLASMODIUM FALCIPARUM; PLASMODIUM VIVAX; PLASMODIUM OVALE; and PLASMODIUM MALARIAE; and transmitted by the bite of an infected female mosquito of the genus ANOPHELES. Malaria is endemic in parts of Asia, Africa, Central and South America, Oceania, and certain Caribbean islands. It is characterized by extreme exhaustion associated with paroxysms of high FEVER; SWEATING; shaking CHILLS; and ANEMIA. Malaria in ANIMALS is caused by other species of plasmodia.Antibodies, Bacterial: Immunoglobulins produced in a response to BACTERIAL ANTIGENS.T-Lymphocytes: Lymphocytes responsible for cell-mediated immunity. Two types have been identified - cytotoxic (T-LYMPHOCYTES, CYTOTOXIC) and helper T-lymphocytes (T-LYMPHOCYTES, HELPER-INDUCER). They are formed when lymphocytes circulate through the THYMUS GLAND and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen.Zoonoses: Diseases of non-human animals that may be transmitted to HUMANS or may be transmitted from humans to non-human animals.Feces: Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.Paratuberculosis: A chronic GASTROENTERITIS in RUMINANTS caused by MYCOBACTERIUM AVIUM SUBSPECIES PARATUBERCULOSIS.Prevalence: The total number of cases of a given disease in a specified population at a designated time. It is differentiated from INCIDENCE, which refers to the number of new cases in the population at a given time.Interferon-gamma: The major interferon produced by mitogenically or antigenically stimulated LYMPHOCYTES. It is structurally different from TYPE I INTERFERON and its major activity is immunoregulation. It has been implicated in the expression of CLASS II HISTOCOMPATIBILITY ANTIGENS in cells that do not normally produce them, leading to AUTOIMMUNE DISEASES.Antibody Formation: The production of ANTIBODIES by proliferating and differentiated B-LYMPHOCYTES under stimulation by ANTIGENS.CD8-Positive T-Lymphocytes: A critical subpopulation of regulatory T-lymphocytes involved in MHC Class I-restricted interactions. They include both cytotoxic T-lymphocytes (T-LYMPHOCYTES, CYTOTOXIC) and CD8+ suppressor T-lymphocytes.Immunoglobulin G: The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.CD4-Positive T-Lymphocytes: A critical subpopulation of T-lymphocytes involved in the induction of most immunological functions. The HIV virus has selective tropism for the T4 cell which expresses the CD4 phenotypic marker, a receptor for HIV. In fact, the key element in the profound immunosuppression seen in HIV infection is the depletion of this subset of T-lymphocytes.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Mice, Knockout: Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.Disease Vectors: Invertebrates or non-human vertebrates which transmit infective organisms from one host to another.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Anopheles: A genus of mosquitoes (CULICIDAE) that are known vectors of MALARIA.Goat Diseases: Diseases of the domestic or wild goat of the genus Capra.Bovine Virus Diarrhea-Mucosal Disease: Acute disease of cattle caused by the bovine viral diarrhea viruses (DIARRHEA VIRUSES, BOVINE VIRAL). Often mouth ulcerations are the only sign but fever, diarrhea, drop in milk yield, and loss of appetite are also seen. Severity of clinical disease varies and is strain dependent. Outbreaks are characterized by low morbidity and high mortality.Prince Edward Island: An island in the Gulf of St. Lawrence constituting a province of Canada in the eastern part of the country. It is very irregular in shape with many deep inlets. Its capital is Charlottetown. Discovered by the French in 1534 and originally named Ile Saint-Jean, it was renamed in 1799 in honor of Prince Edward, fourth son of George III and future father of Queen Victoria. (From Webster's New Geographical Dictionary, 1988, p981 & Room, Brewer's Dictionary of Names, 1992, p433)Lymphocyte Activation: Morphologic alteration of small B LYMPHOCYTES or T LYMPHOCYTES in culture into large blast-like cells able to synthesize DNA and RNA and to divide mitotically. It is induced by INTERLEUKINS; MITOGENS such as PHYTOHEMAGGLUTININS, and by specific ANTIGENS. It may also occur in vivo as in GRAFT REJECTION.Breeding: The production of offspring by selective mating or HYBRIDIZATION, GENETIC in animals or plants.Excitatory Postsynaptic Potentials: Depolarization of membrane potentials at the SYNAPTIC MEMBRANES of target neurons during neurotransmission. Excitatory postsynaptic potentials can singly or in summation reach the trigger threshold for ACTION POTENTIALS.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Housing, AnimalEndemic Diseases: The constant presence of diseases or infectious agents within a given geographic area or population group. It may also refer to the usual prevalence of a given disease with such area or group. It includes holoendemic and hyperendemic diseases. A holoendemic disease is one for which a high prevalent level of infection begins early in life and affects most of the child population, leading to a state of equilibrium such that the adult population shows evidence of the disease much less commonly than do children (malaria in many communities is a holoendemic disease). A hyperendemic disease is one that is constantly present at a high incidence and/or prevalence rate and affects all groups equally. (Last, A Dictionary of Epidemiology, 3d ed, p53, 78, 80)Viral Vaccines: Suspensions of attenuated or killed viruses administered for the prevention or treatment of infectious viral disease.HIV-1: The type species of LENTIVIRUS and the etiologic agent of AIDS. It is characterized by its cytopathic effect and affinity for the T4-lymphocyte.Spleen: An encapsulated lymphatic organ through which venous blood filters.Mycobacterium avium subsp. paratuberculosis: A subspecies of gram-positive, aerobic bacteria. It is the etiologic agent of Johne's disease (PARATUBERCULOSIS), a chronic GASTROENTERITIS in RUMINANTS.Cytokines: Non-antibody proteins secreted by inflammatory leukocytes and some non-leukocytic cells, that act as intercellular mediators. They differ from classical hormones in that they are produced by a number of tissue or cell types rather than by specialized glands. They generally act locally in a paracrine or autocrine rather than endocrine manner.Synapses: Specialized junctions at which a neuron communicates with a target cell. At classical synapses, a neuron's presynaptic terminal releases a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell. The target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell. Neurons may also communicate via direct electrical coupling with ELECTRICAL SYNAPSES. Several other non-synaptic chemical or electric signal transmitting processes occur via extracellular mediated interactions.Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Goats: Any of numerous agile, hollow-horned RUMINANTS of the genus Capra, in the family Bovidae, closely related to the SHEEP.Culicidae: A family of the order DIPTERA that comprises the mosquitoes. The larval stages are aquatic, and the adults can be recognized by the characteristic WINGS, ANIMAL venation, the scales along the wing veins, and the long proboscis. Many species are of particular medical importance.Coccidiosis: Protozoan infection found in animals and man. It is caused by several different genera of COCCIDIA.Malaria, Falciparum: Malaria caused by PLASMODIUM FALCIPARUM. This is the severest form of malaria and is associated with the highest levels of parasites in the blood. This disease is characterized by irregularly recurring febrile paroxysms that in extreme cases occur with acute cerebral, renal, or gastrointestinal manifestations.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Antibodies, Protozoan: Immunoglobulins produced in a response to PROTOZOAN ANTIGENS.Host-Pathogen Interactions: The interactions between a host and a pathogen, usually resulting in disease.Reproduction: The total process by which organisms produce offspring. (Stedman, 25th ed)Bison: A genus of the family Bovidae having two species: B. bison and B. bonasus. This concept is differentiated from BUFFALOES, which refers to Bubalus arnee and Syncerus caffer.Infant, Newborn: An infant during the first month after birth.Orthomyxoviridae Infections: Virus diseases caused by the ORTHOMYXOVIRIDAE.Saskatchewan: A province of Canada, lying between the provinces of Alberta and Manitoba. Its capital is Regina. It is entirely a plains region with prairie in the south and wooded country with many lakes and swamps in the north. The name was taken from the Saskatchewan River from the Cree name Kisiskatchewani Sipi, meaning rapid-flowing river. (From Webster's New Geographical Dictionary, 1988, p1083 & Room, Brewer's Dictionary of Names, 1992, p486)Host-Parasite Interactions: The relationship between an invertebrate and another organism (the host), one of which lives at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.Lactation: The processes of milk secretion by the maternal MAMMARY GLANDS after PARTURITION. The proliferation of the mammary glandular tissue, milk synthesis, and milk expulsion or let down are regulated by the interactions of several hormones including ESTRADIOL; PROGESTERONE; PROLACTIN; and OXYTOCIN.Adjuvants, Immunologic: Substances that augment, stimulate, activate, potentiate, or modulate the immune response at either the cellular or humoral level. The classical agents (Freund's adjuvant, BCG, Corynebacterium parvum, et al.) contain bacterial antigens. Some are endogenous (e.g., histamine, interferon, transfer factor, tuftsin, interleukin-1). Their mode of action is either non-specific, resulting in increased immune responsiveness to a wide variety of antigens, or antigen-specific, i.e., affecting a restricted type of immune response to a narrow group of antigens. The therapeutic efficacy of many biological response modifiers is related to their antigen-specific immunoadjuvanticity.Neospora: A genus of protozoan parasites of the subclass COCCIDIA. Its species are parasitic in dogs, cattle, goats, and sheep, among others. N. caninum, a species that mainly infects dogs, is intracellular in neural and other cells of the body, multiplies by endodyogeny, has no parasitophorous vacuole, and has numerous rhoptries. It is known to cause lesions in many tissues, especially the brain and spinal cord as well as abortion in the expectant mother.Salmonella Infections, Animal: Infections in animals with bacteria of the genus SALMONELLA.Plasmodium falciparum: A species of protozoa that is the causal agent of falciparum malaria (MALARIA, FALCIPARUM). It is most prevalent in the tropics and subtropics.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Animals, Wild: Animals considered to be wild or feral or not adapted for domestic use. It does not include wild animals in zoos for which ANIMALS, ZOO is available.Microscopy, Electron: Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.Animals, Newborn: Refers to animals in the period of time just after birth.Insect Bites and Stings: Bites and stings inflicted by insects.Vaccines, Attenuated: Live vaccines prepared from microorganisms which have undergone physical adaptation (e.g., by radiation or temperature conditioning) or serial passage in laboratory animal hosts or infected tissue/cell cultures, in order to produce avirulent mutant strains capable of inducing protective immunity.Vaccines, DNA: Recombinant DNA vectors encoding antigens administered for the prevention or treatment of disease. The host cells take up the DNA, express the antigen, and present it to the immune system in a manner similar to that which would occur during natural infection. This induces humoral and cellular immune responses against the encoded antigens. The vector is called naked DNA because there is no need for complex formulations or delivery agents; the plasmid is injected in saline or other buffers.Mustelidae: A family of terrestrial carnivores with long, slender bodies, long tails, and anal scent glands. They include badgers, weasels, martens, FERRETS; MINKS; wolverines, polecats, and OTTERS.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Virus Shedding: The expelling of virus particles from the body. Important routes include the respiratory tract, genital tract, and intestinal tract. Virus shedding is an important means of vertical transmission (INFECTIOUS DISEASE TRANSMISSION, VERTICAL).Hypersensitivity, Delayed: An increased reactivity to specific antigens mediated not by antibodies but by cells.Carrier State: The condition of harboring an infective organism without manifesting symptoms of infection. The organism must be readily transmissible to another susceptible host.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Deer: The family Cervidae of 17 genera and 45 species occurring nearly throughout North America, South America, and Eurasia, on most associated continental islands, and in northern Africa. Wild populations of deer have been established through introduction by people in Cuba, New Guinea, Australia, New Zealand, and other places where the family does not naturally occur. They are slim, long-legged and best characterized by the presence of antlers. Their habitat is forests, swamps, brush country, deserts, and arctic tundra. They are usually good swimmers; some migrate seasonally. (Walker's Mammals of the World, 5th ed, p1362)Vaccines, Synthetic: Small synthetic peptides that mimic surface antigens of pathogens and are immunogenic, or vaccines manufactured with the aid of recombinant DNA techniques. The latter vaccines may also be whole viruses whose nucleic acids have been modified.Electric Stimulation: Use of electric potential or currents to elicit biological responses.Antigens, Bacterial: Substances elaborated by bacteria that have antigenic activity.Genetic Variation: Genotypic differences observed among individuals in a population.Cluster Analysis: A set of statistical methods used to group variables or observations into strongly inter-related subgroups. In epidemiology, it may be used to analyze a closely grouped series of events or cases of disease or other health-related phenomenon with well-defined distribution patterns in relation to time or place or both.Influenza, Human: An acute viral infection in humans involving the respiratory tract. It is marked by inflammation of the NASAL MUCOSA; the PHARYNX; and conjunctiva, and by headache and severe, often generalized, myalgia.Immunologic Memory: The altered state of immunologic responsiveness resulting from initial contact with antigen, which enables the individual to produce antibodies more rapidly and in greater quantity in response to secondary antigenic stimulus.Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.Models, Immunological: Theoretical representations that simulate the behavior or activity of immune system, processes, or phenomena. They include the use of mathematical equations, computers, and other electrical equipment.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Neurons: The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Cancer Vaccines: Vaccines or candidate vaccines designed to prevent or treat cancer. Vaccines are produced using the patient's own whole tumor cells as the source of antigens, or using tumor-specific antigens, often recombinantly produced.Bacterial Shedding: The expelling of bacteria from the body. Important routes include the respiratory tract, genital tract, and intestinal tract.Diarrhea Viruses, Bovine Viral: A group of viruses in the genus PESTIVIRUS, causing diarrhea, fever, oral ulcerations, hemorrhagic syndrome, and various necrotic lesions among cattle and other domestic animals. The two species (genotypes), BVDV-1 and BVDV-2 , exhibit antigenic and pathological differences. The historical designation, BVDV, consisted of both (then unrecognized) genotypes.Infectious Disease Transmission, Professional-to-Patient: The transmission of infectious disease or pathogens from health professional or health care worker to patients. It includes transmission via direct or indirect exposure to bacterial, fungal, parasitic, or viral agents.Disease Susceptibility: A constitution or condition of the body which makes the tissues react in special ways to certain extrinsic stimuli and thus tends to make the individual more than usually susceptible to certain diseases.T-Lymphocytes, Cytotoxic: Immunized T-lymphocytes which can directly destroy appropriate target cells. These cytotoxic lymphocytes may be generated in vitro in mixed lymphocyte cultures (MLC), in vivo during a graft-versus-host (GVH) reaction, or after immunization with an allograft, tumor cell or virally transformed or chemically modified target cell. The lytic phenomenon is sometimes referred to as cell-mediated lympholysis (CML). These CD8-positive cells are distinct from NATURAL KILLER CELLS and NATURAL KILLER T-CELLS. There are two effector phenotypes: TC1 and TC2.Neutralization Tests: The measurement of infection-blocking titer of ANTISERA by testing a series of dilutions for a given virus-antiserum interaction end-point, which is generally the dilution at which tissue cultures inoculated with the serum-virus mixtures demonstrate cytopathology (CPE) or the dilution at which 50% of test animals injected with serum-virus mixtures show infectivity (ID50) or die (LD50).Th1 Cells: Subset of helper-inducer T-lymphocytes which synthesize and secrete interleukin-2, gamma-interferon, and interleukin-12. Due to their ability to kill antigen-presenting cells and their lymphokine-mediated effector activity, Th1 cells are associated with vigorous delayed-type hypersensitivity reactions.Virus Diseases: A general term for diseases produced by viruses.Epidemics: Sudden outbreaks of a disease in a country or region not previously recognized in that area, or a rapid increase in the number of new cases of a previous existing endemic disease. Epidemics can also refer to outbreaks of disease in animal or plant populations.Sheep Diseases: Diseases of domestic and mountain sheep of the genus Ovis.Mycobacterium bovis: The bovine variety of the tubercle bacillus. It is called also Mycobacterium tuberculosis var. bovis.Veterinary Medicine: The medical science concerned with the prevention, diagnosis, and treatment of diseases in animals.Models, Theoretical: Theoretical representations that simulate the behavior or activity of systems, processes, or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.Macrophages: The relatively long-lived phagocytic cell of mammalian tissues that are derived from blood MONOCYTES. Main types are PERITONEAL MACROPHAGES; ALVEOLAR MACROPHAGES; HISTIOCYTES; KUPFFER CELLS of the liver; and OSTEOCLASTS. They may further differentiate within chronic inflammatory lesions to EPITHELIOID CELLS or may fuse to form FOREIGN BODY GIANT CELLS or LANGHANS GIANT CELLS. (from The Dictionary of Cell Biology, Lackie and Dow, 3rd ed.)Vaccines: Suspensions of killed or attenuated microorganisms (bacteria, viruses, fungi, protozoa), antigenic proteins, synthetic constructs, or other bio-molecular derivatives, administered for the prevention, amelioration, or treatment of infectious and other diseases.Microscopy, Electron, Scanning: Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.Porcine Reproductive and Respiratory Syndrome: A syndrome characterized by outbreaks of late term abortions, high numbers of stillbirths and mummified or weak newborn piglets, and respiratory disease in young unweaned and weaned pigs. It is caused by PORCINE RESPIRATORY AND REPRODUCTIVE SYNDROME VIRUS. (Radostits et al., Veterinary Medicine, 8th ed, p1048)Immunization, Secondary: Any immunization following a primary immunization and involving exposure to the same or a closely related antigen.Molecular Epidemiology: The application of molecular biology to the answering of epidemiological questions. The examination of patterns of changes in DNA to implicate particular carcinogens and the use of molecular markers to predict which individuals are at highest risk for a disease are common examples.Plasmodium: A genus of protozoa that comprise the malaria parasites of mammals. Four species infect humans (although occasional infections with primate malarias may occur). These are PLASMODIUM FALCIPARUM; PLASMODIUM MALARIAE; PLASMODIUM OVALE, and PLASMODIUM VIVAX. Species causing infection in vertebrates other than man include: PLASMODIUM BERGHEI; PLASMODIUM CHABAUDI; P. vinckei, and PLASMODIUM YOELII in rodents; P. brasilianum, PLASMODIUM CYNOMOLGI; and PLASMODIUM KNOWLESI in monkeys; and PLASMODIUM GALLINACEUM in chickens.Weaning: Permanent deprivation of breast milk and commencement of nourishment with other food. (From Stedman, 25th ed)Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Toll-Like Receptors: A family of pattern recognition receptors characterized by an extracellular leucine-rich domain and a cytoplasmic domain that share homology with the INTERLEUKIN 1 RECEPTOR and the DROSOPHILA toll protein. Following pathogen recognition, toll-like receptors recruit and activate a variety of SIGNAL TRANSDUCING ADAPTOR PROTEINS.Buffaloes: Ruminants of the family Bovidae consisting of Bubalus arnee and Syncerus caffer. This concept is differentiated from BISON, which refers to Bison bison and Bison bonasus.Antigens, Protozoan: Any part or derivative of any protozoan that elicits immunity; malaria (Plasmodium) and trypanosome antigens are presently the most frequently encountered.Animals, Domestic: Animals which have become adapted through breeding in captivity to a life intimately associated with humans. They include animals domesticated by humans to live and breed in a tame condition on farms or ranches for economic reasons, including LIVESTOCK (specifically CATTLE; SHEEP; HORSES; etc.), POULTRY; and those raised or kept for pleasure and companionship, e.g., PETS; or specifically DOGS; CATS; etc.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Incidence: The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from PREVALENCE, which refers to all cases, new or old, in the population at a given time.Receptors, Pattern Recognition: A large family of cell surface receptors that bind conserved molecular structures (PAMPS) present in pathogens. They play important roles in host defense by mediating cellular responses to pathogens.Communicable Disease Control: Programs of surveillance designed to prevent the transmission of disease by any means from person to person or from animal to man.Tuberculosis: Any of the infectious diseases of man and other animals caused by species of MYCOBACTERIUM.Kenya: A republic in eastern Africa, south of ETHIOPIA, west of SOMALIA with TANZANIA to its south, and coastline on the Indian Ocean. Its capital is Nairobi.Brucellosis, Bovine: A disease of cattle caused by bacteria of the genus BRUCELLA leading to abortion in late pregnancy. BRUCELLA ABORTUS is the primary infective agent.Lung: Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.Administration, Intranasal: Delivery of medications through the nasal mucosa.Population Density: Number of individuals in a population relative to space.Presynaptic Terminals: The distal terminations of axons which are specialized for the release of neurotransmitters. Also included are varicosities along the course of axons which have similar specializations and also release transmitters. Presynaptic terminals in both the central and peripheral nervous systems are included.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Bacterial Proteins: Proteins found in any species of bacterium.Infectious Disease Transmission, Patient-to-Professional: The transmission of infectious disease or pathogens from patients to health professionals or health care workers. It includes transmission via direct or indirect exposure to bacterial, fungal, parasitic, or viral agents.Contact Tracing: Identification of those persons (or animals) who have had such an association with an infected person, animal, or contaminated environment as to have had the opportunity to acquire the infection. Contact tracing is a generally accepted method for the control of sexually transmitted diseases.Antibodies, Neutralizing: Antibodies that reduce or abolish some biological activity of a soluble antigen or infectious agent, usually a virus.Basic Reproduction Number: The expected number of new cases of an infection caused by an infected individual, in a population consisting of susceptible contacts only.Immunoglobulin A: Represents 15-20% of the human serum immunoglobulins, mostly as the 4-chain polymer in humans or dimer in other mammals. Secretory IgA (IMMUNOGLOBULIN A, SECRETORY) is the main immunoglobulin in secretions.Viral Load: The quantity of measurable virus in a body fluid. Change in viral load, measured in plasma, is sometimes used as a SURROGATE MARKER in disease progression.Immune System: The body's defense mechanism against foreign organisms or substances and deviant native cells. It includes the humoral immune response and the cell-mediated response and consists of a complex of interrelated cellular, molecular, and genetic components.Mycobacterium tuberculosis: A species of gram-positive, aerobic bacteria that produces TUBERCULOSIS in humans, other primates, CATTLE; DOGS; and some other animals which have contact with humans. Growth tends to be in serpentine, cordlike masses in which the bacilli show a parallel orientation.Plant Diseases: Diseases of plants.Glutamic Acid: A non-essential amino acid naturally occurring in the L-form. Glutamic acid is the most common excitatory neurotransmitter in the CENTRAL NERVOUS SYSTEM.Parasitemia: The presence of parasites (especially malarial parasites) in the blood. (Dorland, 27th ed)RNA, Viral: Ribonucleic acid that makes up the genetic material of viruses.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Patch-Clamp Techniques: An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.Vagina: The genital canal in the female, extending from the UTERUS to the VULVA. (Stedman, 25th ed)Flow Cytometry: Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.Neural Inhibition: The function of opposing or restraining the excitation of neurons or their target excitable cells.Influenza A Virus, H1N1 Subtype: A subtype of INFLUENZA A VIRUS with the surface proteins hemagglutinin 1 and neuraminidase 1. The H1N1 subtype was responsible for the Spanish flu pandemic of 1918.gamma-Aminobutyric Acid: The most common inhibitory neurotransmitter in the central nervous system.Neuromuscular Junction: The synapse between a neuron and a muscle.Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Immune Tolerance: The specific failure of a normally responsive individual to make an immune response to a known antigen. It results from previous contact with the antigen by an immunologically immature individual (fetus or neonate) or by an adult exposed to extreme high-dose or low-dose antigen, or by exposure to radiation, antimetabolites, antilymphocytic serum, etc.Interleukin-12: A heterodimeric cytokine that plays a role in innate and adaptive immune responses. Interleukin-12 is a 70 kDa protein that is composed of covalently linked 40 kDa and 35 kDa subunits. It is produced by DENDRITIC CELLS; MACROPHAGES and a variety of other immune cells and plays a role in the stimulation of INTERFERON-GAMMA production by T-LYMPHOCYTES and NATURAL KILLER CELLS.Circoviridae Infections: Virus diseases caused by the CIRCOVIRIDAE.Antigens, Viral: Substances elaborated by viruses that have antigenic activity.Records as Topic: The commitment in writing, as authentic evidence, of something having legal importance. The concept includes certificates of birth, death, etc., as well as hospital, medical, and other institutional records.Virulence: The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its VIRULENCE FACTORS.Salmonella: A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that utilizes citrate as a sole carbon source. It is pathogenic for humans, causing enteric fevers, gastroenteritis, and bacteremia. Food poisoning is the most common clinical manifestation. Organisms within this genus are separated on the basis of antigenic characteristics, sugar fermentation patterns, and bacteriophage susceptibility.Porcine respiratory and reproductive syndrome virus: A species of ARTERIVIRUS causing reproductive and respiratory disease in pigs. The European strain is called Lelystad virus. Airborne transmission is common.Hippocampus: A curved elevation of GRAY MATTER extending the entire length of the floor of the TEMPORAL HORN of the LATERAL VENTRICLE (see also TEMPORAL LOBE). The hippocampus proper, subiculum, and DENTATE GYRUS constitute the hippocampal formation. Sometimes authors include the ENTORHINAL CORTEX in the hippocampal formation.Mucous Membrane: An EPITHELIUM with MUCUS-secreting cells, such as GOBLET CELLS. It forms the lining of many body cavities, such as the DIGESTIVE TRACT, the RESPIRATORY TRACT, and the reproductive tract. Mucosa, rich in blood and lymph vessels, comprises an inner epithelium, a middle layer (lamina propria) of loose CONNECTIVE TISSUE, and an outer layer (muscularis mucosae) of SMOOTH MUSCLE CELLS that separates the mucosa from submucosa.Killer Cells, Natural: Bone marrow-derived lymphocytes that possess cytotoxic properties, classically directed against transformed and virus-infected cells. Unlike T CELLS; and B CELLS; NK CELLS are not antigen specific. The cytotoxicity of natural killer cells is determined by the collective signaling of an array of inhibitory and stimulatory CELL SURFACE RECEPTORS. A subset of T-LYMPHOCYTES referred to as NATURAL KILLER T CELLS shares some of the properties of this cell type.Computer Simulation: Computer-based representation of physical systems and phenomena such as chemical processes.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.B-Lymphocytes: Lymphoid cells concerned with humoral immunity. They are short-lived cells resembling bursa-derived lymphocytes of birds in their production of immunoglobulin upon appropriate stimulation.Age Factors: Age as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or the effect of a circumstance. It is used with human or animal concepts but should be differentiated from AGING, a physiological process, and TIME FACTORS which refers only to the passage of time.Vaccines, Inactivated: Vaccines in which the infectious microbial nucleic acid components have been destroyed by chemical or physical treatment (e.g., formalin, beta-propiolactone, gamma radiation) without affecting the antigenicity or immunogenicity of the viral coat or bacterial outer membrane proteins.Lymphocytes: White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.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.Listeriosis: Infections with bacteria of the genus LISTERIA.Larva: Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.Bacteriocins: Substances elaborated by specific strains of bacteria that are lethal against other strains of the same or related species. They are protein or lipopolysaccharide-protein complexes used in taxonomy studies of bacteria.Mice, Inbred C3H
If people are immunized broadly, herd immunity results, with a decrease in the amount of contamination in the environment. An ... Transmission is usually through the fecal-oral route of contaminated food or water caused by poor sanitation. Most cholera ... Governments can play a role in all of these areas. Although cholera may be life-threatening, prevention of the disease is ... Persons with lowered immunity, such as persons with AIDS or malnourished children, are more likely to experience a severe case ...
The immunity of both the definitive and intermediate host plays a large role in the transmission of the parasite, as well as ... the contact rate between the intermediate and the definitive host (such as herding dogs and pasture animals being kept in close ... May 2004). "Transmission dynamics of the Echinococcus granulosus sheep-dog strain (G1 genotype) in camels in Tunisia". Vet. ... In order to prevent transmission to dogs from intermediate hosts, dogs can be given anthelminthic vaccinations. In the case of ...
... role and identification of infection reservoirs If the proportion of the population that is immune exceeds the herd immunity ... Therefore, the basic reproduction number is R0 = β/γ This value quantifies the transmission potential of a disease. If the ... The WHO is carrying out a similar vaccination campaign to eradicate polio.[citation needed] The herd immunity level will be ... where upon recovery there is no immunity (SIS model), where immunity lasts only for a short period of time (SIRS), where there ...
Role of herd immunity in determining the effect of vaccines against sexually transmitted disease. The Journal of Infectious ... Horizontal transmission is the most common mechanism of spread of viruses in populations. Transmission can occur when: body ... Its role in immunity is complex; it eventually stops the viruses from reproducing by killing the infected cell and its close ... confer immunity. Such viruses are called attenuated. Live vaccines can be dangerous when given to people with a weak immunity ( ...
Herd immunity, immunity that occurs when an entire group of people become immune to a particular infection, occurs from ... Transmission is common in day cares and at schools, due to the closeness of many children with little immunity and frequently ... This is how the disease got its name.[18] The role of body cooling as a risk factor for the common cold is controversial.[19] ... Transmission[change , change source]. The common cold virus is usually spread in one of two main ways. By breathing or ...
Herd immunity, generated from previous exposure to cold viruses, plays an important role in limiting viral spread, as seen with ... Transmission is common in daycare and at school due to the proximity of many children with little immunity and frequently poor ... There is some controversy over the role of low body temperature as a risk factor for the common cold; the majority of the ... There is no evidence that recirculated air during commercial flight is a method of transmission. People sitting in close ...
Climate appears to play a crucial role in the transmission of RHD. In normal conditions, most outbreaks of RHD occur in winter ... Morbidity, mortality, and immunity[edit]. RHD is extremely hard to locate in the wild since about 75% of rabbits with RHD will ... RHD may be indicated when several animals in the herd die after experiencing a fever and lethargy. Differential diagnosis ... Transmission[edit]. Transmission of RHD occurs by direct contact with an infected animal and fomites. Rabbits acquire RHD ...
Herd immunity False positives and false negatives Rare disease Hilda Mary Woods - the first author (with William Russell) of ... It has a central role in medical investigations. It not only provides a way of organizing information on a wider and more ... and giving a "positive" result). Transmission rate vs. Force of infection Mortality rate vs. Standardized mortality ratio vs. ...
... resulting in adaptive immunity. Vaccination in a population results in herd immunity and greatly improved population health, ... Roles of pharmacists and pharmacies have also expanded to meet the needs of public during public health emergencies. ... WHO further recommends in-depth epidemiological investigations to control potential transmission of the resistant virus and ... Low vaccine-preventable disease rates as a result of herd immunity also make vaccines seem unnecessary and leave many ...
The herd immunity level will be denoted q. Recall that, for a stable state: R. 0. ⋅. S. =. 1.. {\displaystyle R_{0}\cdot S=1.} ... This is the transmission probability times the contact rate. Besides, an infected individual makes contact with b. {\ ... role of host genetic factors. *statistical and mathematical tools and innovations. *role and identification of infection ... If the proportion of the population that is immune exceeds the herd immunity level for the disease, then the disease can no ...
Retroviral fusogenic env proteins, which play a role in the entry of the virion into the host cell, have had an important ... In terms of immunity, researchers concluded that MER41.AIM2 is necessary for an inflammatory response to infection. ... Although known infectious pathogens present in the donor organ/tissue can be eliminated by breeding pathogen-free herds, ... The consequences of cross-species transmission remains unexplored and has very dangerous potential. Researchers indicated that ...
Climate appears to play a crucial role in the transmission of RHD.[citation needed] In normal conditions, most outbreaks of RHD ... The immunity does not survive through the next generation, leaving open the possibility of further outbreaks in the population ... RHD may be indicated when several animals in the herd die after experiencing a fever and lethargy. Differential diagnosis ... Transmission of RHD occurs by direct contact with an infected animal and fomites. Rabbits acquire RHD through oral, nasal or ...
... secondary transmission routes between humans with or without fleas, human herd immunity, and changes in each might explain the ... 2010) by a multinational team that investigated the role of Yersinia pestis in the Black Death. The paper detailed the results ... The dynamic complexities of rat ecology, herd immunity in that reservoir, interaction with human ecology, ... Efficient transmission of Yersinia pestis is generally thought to occur only through the bites of fleas whose mid guts become ...
The particular role of each of these insects in the transmission of LSD continues to be evaluated. Outbreaks of lumpy skin ... In Kenya, the vaccine produced from sheep or goatpox viruses has been shown to provide immunity in cattle. However, the level ... During a period of 37 days between August and September 1989, fourteen of the seventeen dairy herds in Peduyim became infected ... Most cattle develop life-long immunity after recovery from a natural infection. Additionally, calves of immune cows acquire ...
Garnett, G. P. (1 February 2005). "Role of Herd Immunity in Determining the Effect of Vaccines against Sexually Transmitted ... In these networks, transmission only occurs between those who are geographically or physically close to one another. The shape ... Herd immunity (also called herd effect, community immunity, population immunity, or social immunity) is a form of indirect ... Tetanus, for example, is infectious but not contagious, so herd immunity does not apply. The term herd immunity was first used ...
Contaminated equipment is another major transmission factor and insect vectors play a minor role. SPV is mainly spread to new ... Infected animals may be quarantined and new animals should be isolated from the infected herds while transmission is still ... Symptoms can range from mild to severe depending on things such as age, breed, and immunity of the host. The virulence of the ... If necessary, slaughtering or euthanasia of the herd can help prevent further disease transmission. Crucial is the proper ...
Horizontal transmission plays an important role among livestock due to their often close quarters, especially during winter ... Attempts at vaccination against maedi-visna virus have failed to induce immunity, occasionally causing increased viremia and ... refer to endemic sheep herd conditions that were only found to be related after Sigurdsson's work. Visna infection may progress ... Sexual transmission has also been shown to be possible No link has yet been made between transmission and other excretory ...
In light of human potential to develop herd immunity via vaccination in advance of a pandemic strain, the time that it allows ... Until May 2006, the WHO estimate of the number of human to human transmission had been "two or three cases". On May 24, 2006, ... The PB1-F2 protein probably contributes to viral pathogenicity and might have an important role in determining the severity of ... Indeed, if there is sufficient immunity to stop it at the source, it will not become pandemic. As long as the likelihood of ...
The inbreeding of the species caused by the small population plays a role in a number of genetic defects and immunity to ... They are nomadic grazers and travel in herds. The bulls leave the herds of females at two or three years of age, and join a ... In the state of Montana, free-ranging bison on public lands may be shot, due to concerns about transmission of disease to ... B. latifrons is believed to have been a more woodland-dwelling, non-herding species, while B. antiquus was a herding grassland- ...
NAUG, DHRUBA; CAMAZINE, SCOTT (2002-04-21). "The Role of Colony Organization on Pathogen Transmission in Social Insects". ... animal families and social microbes as well as situations where herd immunity exists due to investment in personal immunity, ... Joël Meunier (University of Mainz) proposed a further redefinition in his 2015 paper on the role of social immunity in the ... Social immunity efforts peaks during middle-age, in contrast to efforts in personal immunity increasing or being maintained ...
Because it was endemic in Africa, many people there had acquired immunity. Europeans suffered higher rates of death than did ... Yet, the means of the transmission was unknown until 1881, when Carlos Finlay suggested that the disease was transmitted ... the role of women and children in the family system, and the "superiority of free labor". An example of this type of cultural ... and the animals were considered so valuable that horse herds became a measure of wealth. Still, the effects of the introduction ...
TransmissionEdit. The FMD virus can be transmitted in a number of ways, including close-contact animal-to-animal spread, long- ... About 3,500 livestock herds were infected across the US, totaling over 170,000 cattle, sheep, and swine. The eradication came ... Vaccination only provides temporary immunity that lasts from months to years.. Currently, the World Organisation for Animal ... Wolves are thought to play a similar role in the former Soviet Union.[19] ...
Several other lymnaeid snails may be naturally or experimentally infected with F. hepatica, but their role in transmission of ... These two methods are not always the most practical, so control by treating the herd before they are potentially infected is ... Infection and Immunity. 77 (6): 2488-2498. doi:10.1128/IAI.00919-08. ISSN 0019-9567. Kotpal, RL (2012). Modern Text Book of ... The role of F. hepatica's excretory system is excretion and osmoregulation. Each tubule within the excretory system is ...
"Infection and Immunity. 79 (4): 1407-1417. doi:10.1128/iai.01126-10. PMC 3067569. PMID 21245275.. ... By the early 1880s, the last of the great herds of bison upon which Plains Indian peoples like the Sioux were dependent as a ... Brunarski David (2011). "The Increasing Threat of Syndemics and the Role of Chiropractic Care". Dynamic Chiropractic. 4 (2): 1. ... One disease can assist the physical transmission of the microbe causing another disease, for example, genital-tract ulceration ...
The role of inhibited development in the epidemiology of Ostertagia infections. Vet Parasitol 46: 259-269. Eysker, M. 1993. The ... Due to routine, blanket herd treatment, there is widespread resistance to anthelmintic drugs in warm climates in sheep, and ... Environmental factors influencing transmission. Vet Parasitiol 72: 247-264. Merial. 2016. Endoparasites - Ostertagia. Online ... The immune response and the evaluation of acquired immunity against gastrointestinal nematodes in cattle: a review. Parasitol ...
Megafauna play a significant role in the lateral transport of mineral nutrients in an ecosystem, tending to translocate them ... Kelliher, F. M.; Clark, H. (15 March 2010). "Methane emissions from bison-An historic herd estimate for the North American ... states that the megafaunal die-off was due to an indirect transmission of diseases by newly arriving aboriginal humans.[118][ ... introduced one or more highly virulent diseases into new environments whose native population had no immunity to them, ...
what is the role of herd immunity protects unvaccinated individuals through having sufficiently large proportion of population ... interrupt transmission alter course of infection/disease to prevent or limit consequences (secondary prevention) ...
Herd immunity afforded by exposed persons might play an important role in preventing ongoing virus transmission. Reported ... suggesting that immunity elicited by subclinical or mildly symptomatic infections might play a role in conferring protection ... Dissemination and transmission of the E1-226V variant of chikungunya virus in Aedes albopictus are controlled at the midgut ... the absence of infection in cohort members with baseline neutralizing antibodies in our study suggests the protective role of ...
... to decrease transmission by blocking the acquisition of colonization has been attributed to herd immunity. We describe the role ... leading to protection against carriage acquisition and generation of herd immunity. ...
... including the potential for local interruption of transmission, through raising lasting "herd immunity" (2), or indirect ... waning immunity. Vaccination has long played a central role in the control and eradication of infectious diseases. For ... of herd immunity (e.g., as in the dashed curve in Fig. 1B). Interpreting herd immunity here in its strongest sense, that is, ... Implications of boosting rate σ1 for herd immunity. As in Fig. 1B, we assume a vaccination coverage of 95%. (A) The minimal ...
... because it still remains unclear what role the Aedes mosquito plays in maintaining transmission of the virus," he noted. ... and scientists say herd immunity may be the reason why.. In practical terms, herd immunity means that people traveling to the ... Also, herd immunity does not last forever, so immunity will wane over time, he explained. ... Herd Immunity May Be Curbing U.S. Zika Numbers But smaller future outbreaks are likely, scientists warn By Steven Reinberg. ...
... ability to induce a stronger herd immunity and robust TH17 responses, which confer mucosal immunity, while aP vaccines only ... The researchers also considered the role of several known factors in the rise of whooping cough cases, including detection bias ... The researchers examined mathematical models of pertussis transmission, data derived from the aP and wP vaccines responses in ... Experimental and immunologic data has shown that aP vaccines do not provide herd immunity, while mathematical models imply ...
... because it still remains unclear what role the Aedes mosquito plays in maintaining transmission of the virus, he noted. ... Also, herd immunity does not last forever, so immunity will wane over time, he explained. ... Even if herd immunity is behind the drop in Zika cases, infection experts noted it doesnt guarantee that new outbreaks wont ... Herd immunity may be curbing U.S. Zika numbers. Updated: Friday, August 18, 2017 12:34 AM EDT. time.prefixdate:before{content ...
... was developed to predict the potential impact of PCV7 on the incidence of invasive disease accounting for both herd immunity ... Model projections showed that serotype replacement plays a crucial role in determining the overall effect of a PCV7 vaccination ... A dynamic, age-structured, compartmental model of Streptococcus pneumoniae transmission ... as beneficial direct and herd immunity effects might be countered by serotype replacement. ...
... and therefore do not interrupt person to person transmission. For this reason, they do not result in "herd immunity", which is ... Role of the laboratory. Microbiologists play a critical role in gathering data both for clinical and public health decision ... and may interrupt nasopharyngeal carriage and transmission, resulting in herd immunity. When implemented in national preventive ... Thus, the role of the microbiology laboratory is essential to preventing morbidity and mortality from bacterial meningitis. ...
If people are immunized broadly, herd immunity results, with a decrease in the amount of contamination in the environment. An ... Transmission is usually through the fecal-oral route of contaminated food or water caused by poor sanitation. Most cholera ... Governments can play a role in all of these areas. Although cholera may be life-threatening, prevention of the disease is ... Persons with lowered immunity, such as persons with AIDS or malnourished children, are more likely to experience a severe case ...
... modeling work suggests that the ZIKV epidemic in Latin America should be over in 3 y maximum and that acquired herd immunity ... Global risk model for vector-borne transmission of Zika virus reveals the role of El Niño 2015. Cyril Caminade, Joanne Turner, ... First, we did not consider sexual transmission of ZIKV, because it likely plays a very minor role in the overall amount of ... Correction for Caminade et al., Global risk model for vector-borne transmission of Zika virus reveals the role of El Niño 2015 ...
... and the whole population through herd immunity. In many areas where wild poliovirus transmission has been interrupted, like ... A Public Health Role for Human Genetics. Two non-profit foundations with distinct missions recently announced that they are ... Endemic transmission is now limited to small areas of just three countries-Afghanistan, Nigeria, and Pakistan. ... Other PIs involve defects in innate immunity, immune regulation, or deficiencies in specific components, such as antibodies or ...
The immunity of both the definitive and intermediate host plays a large role in the transmission of the parasite, as well as ... the contact rate between the intermediate and the definitive host (such as herding dogs and pasture animals being kept in close ... May 2004). "Transmission dynamics of the Echinococcus granulosus sheep-dog strain (G1 genotype) in camels in Tunisia". Vet. ... In order to prevent transmission to dogs from intermediate hosts, dogs can be given anthelminthic vaccinations. In the case of ...
... new cases is falling in many places because so many people have already been exposed and that there appears to be herd immunity ... "Well have a lull in transmission, and it will seem like our job is done," Lessler says. "But we need to keep our eye on the ... limiting the scope for testing interventions that could play a role in future outbreaks. They say that the number of ... It spread rapidly because this was a population that had never before been exposed to this virus, and there was no immunity. ...
Changes in age and geographic distribution over time may reflect increased immunity among students resulting from intense ... In these circumstances, herd immunity is sufficient to prevent more widespread transmission. A lower rate of crowding may be ... Behavioral differences between sexes may also play a role.. Most cases occurred in persons who had received 2 doses of MMR, ... exposure to wild-type mumps virus may have boosted individual immunity and thus contributed to increased herd immunity. ...
They acknowledge that pig-to-pig transmission from viraemic pigs could also play a role in the dynamics of the infection but ... and herd immunity did not appear to prevent propagation of the infection. Therefore, the belief that housing environment ... This testing provided evidence for primarily horizontal rather than vertical transmission. Both herds had PCV2-viraemic pigs ... Both herds were negative for porcine reproductive and respiratory syndrome virus (PRRSV) and the MSU herd was negative for ...
1. Is herd immunity a good strategy?. Herd immunity is not part of the Australian strategy for controlling the outbreak. On ... which show that theres no sign of children and young people playing a role in "chains" of transmission. In addition, closing ... Some have claimed the Australian government has plans to rely on "herd immunity" to control the outbreak. Thats not the case. ... Immunity is measured by monitoring the immune cells that fight the virus. As these cells showed up, the virus was no longer ...
Herd immunity. Herd immunity means creating resistance to infection and to the spread of infection in a herd due to the ... Vaccination and virus transmission in herds. The higher the vaccination rate in a population, the lower the infection rate. ... This is why they induce a specific immunity to the parts of the microorganism that play a very important role in the ... Herd immunity is a common term, also used in human medicine to describe the whole population having the same immune status at ...
Furthermore, there was never any argument over the seriousness of SARS and tripe about herd immunity. Health authorities killed ... it off by reducing the transmission rate from above 2 to 0.4 by taking appropriate actions and that is what this government ... The test of immunity is at best random with a poor success rate, both showing false negatives and even worse false positives. ... The role of Public Health England. By johnredwood , Published: April 7, 2020 ...
Vaccine should protect the animals along with reducing the transmission of infectious agents. Ideally the herd immunity is ... also play crucial roles in transmission of various infectious pathogens/diseases like avian/bird flu, Hendra and Nipah viruses ... Due to impact of regular vaccination and building up of herd immunity only a few sporadic cases of FMD could be recorded in the ... The role of wildlife in emerging and re-emerging zoonoses. Rev. Sci. Tech., 23: 497-511.. PubMed , Bergquist, R., 2011. New ...
This age-group was not vaccinated in all provinces, indicating that herd immunity played a role. ... "This study has provided clear evidence that this vaccine likely induced herd immunity by reducing the transmission of N. ... They further suggest that the reduction in MenC carriage with vaccination provides herd immunity. ... indicating that herd protection from reduced carriage of virulent meningococci is an important part of the effectiveness of ...
... outlines how to achieve swine herd immunity based on recent scientific findings. Adapted from remarks given at BIOMIN ... Herd immunity. Herd immunity means creating resistance to infection and to the spread of infection in a herd due to the ... Vaccination and virus transmission in herds. Herd populations with varying levels of vaccination and infection rates are shown ... This is why they induce a specific immunity to the parts of the microorganism that play a very important role in the ...
Role of herd immunity in determining the effect of vaccines against sexually transmitted disease. J Infect Dis2005;191(suppl 1 ... The decline observed in genital warts in younger women in our study is in line with a published model of transmission of human ... This decline was not evident in bisexual men, so it is unlikely to be due to herd immunity resulting from the vaccination of ... The decline in genital warts in the two younger age groups of heterosexual men can most likely be attributed to herd immunity, ...
Role of herd immunity in determining the effect of vaccines against sexually transmitted disease. The Journal of Infectious ... Horizontal transmission is the most common mechanism of spread of viruses in populations. Transmission can occur when: body ... Its role in immunity is complex; it eventually stops the viruses from reproducing by killing the infected cell and its close ... confer immunity. Such viruses are called attenuated. Live vaccines can be dangerous when given to people with a weak immunity ( ...
  • Matthew Aliota, from the department of pathobiological sciences at the University of Wisconsin's School of Veterinary Medicine in Madison, said, "I do believe herd immunity is developing where Zika virus is endemic, but that does not mean Zika will go away. (hon.ch)
  • However, such impact has so far proved more elusive for pathogens such as Bordetella pertussis and Vibrio cholerae ( 3 , 4 ), largely because these infections do not elicit lifelong, sterilizing immunity. (pnas.org)
  • In pertussis, as in all other directly transmitted infections, the structure of the contact network can play an important role, yet has not been quantitatively characterized. (sciencemag.org)
  • Throughout this period, the Swedish Institute for Infectious Disease Control collected incidence data stratified by age ( 13 ) ( Fig. 1, B and C). We combined these data with contact network information from the European POLYMOD study ( 14 ) via an age-structured model with the principal aim of assessing the role of age-specific contacts in pertussis epidemiology. (sciencemag.org)
  • Using wavelet analyses of B. pertussis incidence in the United States (US) and United Kingdom (UK) and a phylodynamic analysis of 36 clinical B. pertussis isolates from the US, we find evidence in support of asymptomatic transmission of B. pertussis. (drpaulapproved.com)
  • Next, we examine the clinical, public health, and epidemiological consequences of asymptomatic B. pertussis transmission using a mathematical model. (drpaulapproved.com)
  • Although a clear role for the previously suggested mechanisms still exists, asymptomatic transmission is the most parsimonious explanation for many of the observations surrounding the resurgence of B. pertussis in the US and UK. (cdc.gov)
  • We describe the role of mucosal immunoglobulin G (IgG) to capsular polysaccharide (CPS) in mediating protection from carriage, translating our findings from a murine model to humans. (nih.gov)
  • by Professor Paolo Martelli, DVM, Diplomate ECPHM, President of the ECPHM, Full Professor of Veterinary Clinical Medicine, Parma University, Italy, outlines how to achieve swine herd immunity based on recent scientific findings. (thepigsite.com)
  • Though larger studies are needed, the findings cast doubt on antibody testing and herd immunity. (cbc.ca)
  • The findings help researchers understand the potential role of age-related GABA decreases in cognitive decline and suggest that declining frontal GABA concentrations may help predict neurodegenerative disease. (news-medical.net)
  • The findings solve a longstanding mystery surrounding the function of IgD, whose role in the immune system has been unclear since it was first observed 50 years ago. (medindia.net)
  • Findings indicate the D614G variant exhibited significantly faster droplet transmission between hamsters and clinical evidence that the D614G mutation could enhance viral loads in the upper respiratory tract of COVID-19 patients and may increase transmission. (who.int)
  • The top health benefits of chamomile tea include the ability to regulate sleep, aid in digestion, boost immunity, protect the skin, lower stress levels, and soothe menstrual cramps. (organicfacts.net)
  • An innovative approach is contact network modeling that captures realistic diversity in contact patterns where diseases may spread along different routes with varying degrees of transmission risk. (springer.com)
  • Herd immunity is the most critical and essential prophylactic intervention that delivers protection against infectious diseases at both the individual and community level. (bvsalud.org)
  • Such an approach might also be useful in stopping transmission of Hendra or other diseases from bats, Dr Redwood added. (abc.net.au)
  • Animal diseases are currently widespread in all agro-ecological zones of the country and annual mortality rates due to diseases is estimated at 8-10% for cattle herds, and 15% and 12% for sheep and goat flocks, respectively. (biomedcentral.com)
  • The level of colostral immunity in a newborn calf is a major determinant of both resistance to and survival of these diseases. (missouri.edu)
  • Both herds were negative for porcine reproductive and respiratory syndrome virus (PRRSV) and the MSU herd was negative for Mycoplasma hyopneumoniae (M. hyo). (thepigsite.com)
  • This paper reviews production systems for preparing gilts that are negative for porcine reproductive and respiratory syndrome virus (PRRSV) to be introduced into infected herds. (aasv.org)
  • The B cells that reside here can make another type of antibody, called IgA, that plays a large role in bringing gut and airway pathogens to heel. (mcall.com)
  • Although all vaccinated and previously infected animals had robust serum antibody responses, we found key differences in T-cell immunity. (drpaulapproved.com)
  • The development of immunity is an important question for the longer term management of COVID-19, the coronavirus at the centre of the pandemic. (australiantimes.co.uk)
  • Dr. Samir Gupta says Alberta's testing may help to understand how far the coronavirus spread but he's doubtful we've reached herd immunity. (cbc.ca)
  • However, Gupta said, people have immunity to coronaviruses that cause common colds for only a few months, and that may also be the case for the coronavirus that causes COVID-19. (cbc.ca)
  • Herd immunity to the novel coronavirus began to emerge globally in July and August 2020 , primarily in poor and elderly communities that were hammered by the first wave of COVID-19 in March and April . (astonisher.com)
  • All over the world right now, in poorer places that were badly hammered by the coronavirus onslaught this spring, we are beginning to see the emergence of "herd immunity" to COVID-19. (astonisher.com)
  • Dr. Talib Dbouk and Professor Dimitris Drikakis speak to News-Medical about how evaporation is essential for coronavirus transmission in the winter. (news-medical.net)
  • Matthew Spinelli, MD, of the University of California San Francisco, said this type of transmission is part of why this epidemic has been so difficult to control in the U.S. (fomatmedical.com)
  • The recent dust-up involving World Health Organization (WHO) statements on asymptomatic and presymptomatic transmission aside, Peter Hotez, MD, PhD, of Baylor College of Medicine in Houston, pointed to "high transmissibility of COVID-19, even among potentially asymptomatic individuals. (fomatmedical.com)
  • Melegaro et al [ 10 ] modeled household transmission using longitudinal data of pneumococcal carriage in the United Kingdom. (springer.com)
  • Since the introduction of pneumococcal vaccine we are starting to see a decline in vaccine type pneumococcal carriage, but the evolution of this process is at a much slower rate than expected from other settings and raises issues about the most appropriate vaccine schedule for use in this setting and the role of vaccinating HIV-infected adults to speed up the development of herd immunity. (lshtm.ac.uk)
  • Going forward we will be continuing to monitor the carriage and transmission of pneumococcus in the post PCV13 period, collecting both empirical data and using models to predict the impact of alternative vaccine schedules. (lshtm.ac.uk)
  • The impact of immunity at the individual level also plays an important role in mitigating the transmission dynamics of pathogens within host populations in a community. (immunopaedia.org.za)
  • A multiscale model was developed to assess the HEV transmission and persistence pattern in the pig production sector through an integrative approach taking into account within-farm dynamics and animal movements based on actual data. (bvsalud.org)
  • Between-herd transmission was modelled by coupling within-herd and network dynamics using the SimInf package. (bvsalud.org)
  • David Aronoff, MD, of Vanderbilt University Medical Center in Nashville, told MedPage Today that non-pharmaceutical interventions, such as masking and social distancing, successfully altered the virus's transmission dynamics, specifically the average number of people one carrier infects, known as R0. (fomatmedical.com)
  • Obesity and high blood pressure may play a much greater role in sudden cardiac arrest among young people than previously thought, a new study suggests. (kctv5.com)
  • In the present study, it was examined if the immunity induced by three West European subtype 1 PRRSV strains (2007 isolate 07V063 and 2013 isolates 13V091 and 13V117) offers protection against the highly virulent East European subtype 3 PRRSV strain Lena. (biomedcentral.com)
  • 2 summarized the results of introducing PRRSV-negative replacement gilts into infected herds. (aasv.org)
  • To successfully control PRRSV, Bone must formulate gilt development strategies that prevent naïve or actively infected replacement stock from being directly introduced into a PRRSV-positive breeding herd. (aasv.org)
  • The purpose of this paper is to provide an overview of four production techniques that have successfully prepared naïve replacement stock for introduction into PRRSV-infected herds. (aasv.org)
  • 5 The IAC system comprises two stages--two separate facilities specifically designed to isolate from and then acclimate gilts to PRRSV prior to entry into infected herds. (aasv.org)
  • Herd immunity afforded by exposed persons might play an important role in preventing ongoing virus transmission. (cdc.gov)
  • In addition, important component of the program is developing the students' understanding of the role of government agencies in animal health and the interactions required with such agencies with respect to parasite prevention, treatment, and control. (cornell.edu)
  • Household member contact is important, whereas contact with children in school does not appear to play an important role in transmission. (tibot.ai)
  • Our results emphasize the important role of house finches and several other passeriform birds in the maintenance and amplification of WNV in southern California, with Cx. (ajtmh.org)
  • stigmatosoma, are important but less widely distributed, and also contribute to spatial and temporal transmission of WNV in southern California. (ajtmh.org)
  • 2009) and it is important to establish which broad groups are present in a herd, area, country or region. (scielo.org.za)
  • Of the parameters tested, group size in day-care centers was shown to be one of the most important factors for pneumococcal transmission. (springer.com)
  • The authors injected adult female Culex tarsalis mosquitoes, an important vector for WNV in humans, with Wolbachia bacteria, which researchers have shown increases mosquitoes' resistance to dengue and malaria, thus blocking transmission to humans. (umn.edu)
  • It also plays an important role in kidney function and skincare. (organicfacts.net)
  • Diminishing levels of GABA, the primary inhibitory neurotransmitter in the brain, may play a role in cognitive decline as we age, according to a study published in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging. (news-medical.net)
  • US - In the latest 'At the Meeting' (ATM) audio program on swine health from the Morrison Group, leading swine veterinarians take on the historic and novel work regarding porcine circovirus (PCV2), including prevention, new diagnostic methods and vertical transmission's impact on pig production and sow herds. (thepigsite.com)
  • Because it means that many hard hit areas - such as New York in the U.S., Bergamo in Italy, and New Delhi in India - have already purchased their herd immunity ticket and had it punched! (astonisher.com)
  • If we are getting figures of one in four or over 50 per cent in urban areas - and all surveys show the same trend - India is moving towards herd immunity, but we need more data," said Dr. Jayaprakash Muliyil, an epidemiologist. (astonisher.com)
  • New Delhi, July 20 (IANS) As the government seeks suggestions from the parents regarding the reopening of schools in the near future, health experts on Monday entered a debate whether reopening schools and colleges will bring herd (community) immunity in India in the absence of a vaccine. (indiatribune.com)
  • Will reopening schools bring herd immunity in India? (ummid.com)
  • Describe the requirements for product development and government approval, and explain the role of government agencies in the approval process. (cornell.edu)
  • Changes in age and geographic distribution over time may reflect increased immunity among students resulting from intense exposure to circulating mumps virus. (cdc.gov)
  • Avian host and mosquito (Diptera: Culicidae) vector competence determine the efficiency of West Nile and St. Louis encephalitis virus transmission. (ajtmh.org)
  • WEDNESDAY, Aug. 16, 2017 (HealthDay News) -- The number of Zika infections has dropped dramatically in Florida this summer, and scientists say herd immunity may be the reason why. (hon.ch)
  • In practical terms, herd immunity means that people traveling to the United States from South America and the Caribbean may have been infected with Zika in the past, but they can no longer pass the virus on to mosquitoes that might pass it on to local residents. (hon.ch)
  • Zika virus (ZIKV) transmission in the Americas was first confirmed in May 2015 in Northeast Brazil1. (zibraproject.org)
  • Two separate studies analyzing the risk associated with Zika transmission in Brazil were published. (courthousenews.com)
  • Each of these pieces of information that we, our collaborators and other scientists around the world are working to gather," says Dr. DeBiasi, "is critical for developing policies that will slow the rate of viral transmission in our community. (scitechdaily.com)