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Parasitology BIOL 4105 Parasites and Socioeconomic s Poverty Associated Factors Increased population density Lack of sanitation Lack of adequate nutrition Lack of health care Lack of education  Some Parasitic diseases endemic in USA! Toxoplasmosis Trichomoniasis Cystic...

Parasitology BIOL 4105 Parasites and Socioeconomic s Poverty Associated Factors Increased population density Lack of sanitation Lack of adequate nutrition Lack of health care Lack of education  Some Parasitic diseases endemic in USA! Toxoplasmosis Trichomoniasis Cysticercosis Toxocariasis (Visceral Larval Migrans) Chagas disease  How would you define a parasite?  Let’s narrow the definition to eukaryotic parasites: Which organisms would fall under this definition? Eukaryotic Parasites Protozoans Single Cell Most have one organelle Kingdom Protista Helminths Multicellular Bilateral symmetry Kingdom Metazoa  Chart of Eukaryotic Parasites Parasite Protozoa Helminth Amebae Flagellates Sporozoa Ciliates Nematodes Cestodes Trematodes Giardia Plasmodia Ascaris Taenia Fasciola Entamoeba Trichomona Babesia Balantidium Ancylostom Echinococc Schistosom Naegleria s Toxoplasma a us a Let’s revisit relationships! 8  Host Parasite Relationships Symbiosis Commensali Mutualism Parasitism sm The Parasite The parasite The Parasite derives benefit Both Host and The parasite is can live Both Host and benefits and but does not Parasite are dependent independently Parasite benefit the Host is cause harm to interdependent upon the host of the host harmed host 9 Classification Ectoparasite more of an infestation than infection (lice, bedbugs, vectors) Endoparasite Obligate Facultative Accidental Aberrant Free-living Are all parasites harmful? Out of 10,000 species of protozoans, 70 infect man. They can either cause pathology themselves by destroying tissues, induce improper immune responses, physically cause blockages or consume our nutrients. So if you are a parasite –some host has to exist. Definitive Intermediate Paratenic Reservoir Accidental/Dead End Life cycle of Angiostrongylus. cantonensis Life Cycle Zoonotic infections are those which are transferred by animals. 13 How does one get a parasitic infection? 14 Contaminated soil Embryonated eggs can be ingested Larva can simply penetrate skin 15 Contaminated water Infectious stage is ingested Intermediate host is swallowed Intermediate host penetrates skin Free living organism gain entrance (amoebas) 16 Food Infective stage on food and veggies Undercooked meat 17 Vector True vectors are key to development of parasite and assist in the transfer of the infectious stage of the organisms Mechanical vectors assist in transfer between hosts but are not essential in the life cycle of the parasite (houseflies for some amoeba) Carriers: Asymptomatic individuals who can transmit the parasite. Self (Autoinfection: Either transfer from one end of host to another (finger to mouth) or complete life cycle occurs internally. 1 8 General Study Guide for Parasitology Life Cycle Disease Distribution Mechanism of Pathogenesis Morphology Mechanism of survival in host Transmission Diagnosis Reproduction Niche Treatment 19  Distribution - Where is it found geographically? - Is this significant? When - Why is or is not found in considering USA? life cycle, think about 20  Morphology What does it look like? What are the stages found in the life cycle and how do their appearance differ? When Are their unique structures that considering help identify each stage? life cycle, think about 21  Transmission: How do parasites get from host to host? Is a vector required? What is infective stage for each host? When considering life cycle, think about 22  Niche selection (tissue predilection) in host * - Is it host specific? - Is it tissue/organ specificity? - Is there a migratory pathway in host tissues? When considering life cycle, think about 23  Reproduction How does parasite reproduce? Sexual reproduction? separate sexes When parthenogenic female considering Asexual reproduction? life cycle, Binary fission? think about Multiple fission (schizogony)? 24