ENTO 208 1st Edition Lecture 8 Outline of Lecture 7I. Types of ReproductionII. Exoskeletona. Partsb. moltingIII. Types of Metamorphosis (3)IV. Tick life-cycleV. Insects as pestsOutline of Lecture 8I. Epidemiologya. Disease Triadb. Definitionsc. Ecosystem Healthd. Epidemiology & modelinge. Vector-borne diseasesCurrent LectureEpidemiologyDisease Triad: Host, Agent, Environment (also sometimes a vector connecting any twoDefinitions:Disease: an abnormality with recognizable signs, symptoms, or laboratory findings caused by nutrition, toxicants, climate, or infectiousInfections (ex: viruses)Non-infectious (ex: electrocution)Epidemic (Epizootic: in animals)Disease that appears as new cases in a given human population, during a given period, at a rate that is substantially exceeds what is "expected", based on recent experienceEndemic (Enzootic: in animals)Normal level of disease that is maintained locally Ecosystem Health/ One HealthDisease of the environment (often anthropogenic [caused by humans])Zoonotic Disease: diseases caused by infectious agents that can be transmitted/ shared between humans and animalsSylvatic-infectious agent picked up by visiting another environmentDomestic-particular agent has become domesticated and thrives in our urban environmentThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Examples: plague, west Nile, Lyme diseaseEmerging Disease-been recently discovered-increase in incidence and/or geographic range-moved into a new species or host population~70% of infectious diseases originated in animalsTransmission cycle:Reservoir host - where reproduction of the infectious organism occursSpill-over (dead-end) host: a host from which infectious agents are not transmitted to susceptible host (agent goes in but does not infect any others)Epidemiology:study factors affecting the health/illness of populationsEpidemic vs. endemicEpi curves: graphs illustrate infection ratesEpidemiological modeling:describe patterns of disease in populations Agent --- DiseaseYersinia psetis --- plaguePlamodium spp ---avian malariaTrypanosoma --- Chagas diseaseWest Nile Virus --- West Nile feverTwo main types of vector borne disease transmissionMechanical: no developmental change in arthropodOften includes a painful bite, mouthparts become contaminatedArthropod behavior leads to increased contact ratesBiologicalPROPAGATIVEINCREASE OF DISEASE agent in vectorCyclodevelopmentalFrom one stage to another but does not multiplyCyclopropagativeDevelopmental change and multiplication Types of vector borne diseaseViralFlavivirusOrbivirusBacterialLyme diseasePlage, e coliProtozoalMalariaFungalPhycomycosisParasiticFilarial nematodes (only come out into the blood at night)Spread of DiseaseHorizontalWithin the same species (i.e. bird to bird)VerticalTransovarial: Mother to child via eggTransplacental: Mother to child via placentaTransstadialFrom one life stage to the next (vector picks up pathogen and remain infected through life stages)Non-viremicCo-feeding transmission (two mosquitoes feeding at the same time, one is infected and it spreads to other through the