Presentation on theme: "Introduction to Medical Parasitology History, Definitions Classification and Taxonomy of Human Parasites Doç.Dr.Hrisi Bahar Doç.Dr.Hrisi Bahar."— Presentation transcript:
1 Introduction to Medical Parasitology History, Definitions Classification and Taxonomy of Human ParasitesDoç.Dr.Hrisi BaharDoç.Dr.Hrisi Bahar
2 ParasitologyParasitology – science about parasitic animals and relationships with their hosts.Para + situ + logos = conversation about those living nearby us= parasitology.
3 History infections come from a period of The first written records of whatare almost certainly parasiticinfections come from a period ofEgyptian medicine from 3000 to400 BC, particularly the Eberspapyrus of 1500 BC discoveredat Thebes.
4 A.lumbricoides eggs have been found in human coprolites from Peru dating from 2277 BC. Larval nematodes,possibly hook worms, have been found in fecal samples dated to about 200 BC from the Colorado PlateauIn 1910, Marc Armand Ruffer foundS.haematobium eggs in two Egyptian mummies dating from the,1250 to 1000 BC
5 A parasite, is an organism that lives on or inside another organism to the detriment of the host organism.The parasite grows, feeds, or uses shelter of the host organism (including the host itself) contributing negatively to the relationship.
6 Parasitism:A symbiotic relationship in which the symbiont (parasite) benefits at the expense of the host by living either within the host (endoparasite) or outside the host (ectoparasite).
7 Types of parasitismObligate parasites:All or most of their life cycle are parasitic.Temporary parasites:parasitic for limited period for either feeding or reproduction.
8 Facultative parasites:organisms are not parasitic but can live parasitic for a limited period. Accidental parasites:normally free living organisms can survive within a host when they are accidentally taken.
9 What is a Parasite Host?The host is the organism that the parasite lives in.*A definitive host* An intermediate host*A paratenic host*A reservoir host
10 Ex: When a human has an adult beef tapeworm in the intestine producing A definitive host is an organism that the adult, or sexually reproductive stage of the parasite lives in.Ex: When a human has an adult beeftapeworm in the intestine producingeggs,he or she is a “definitive host”
11 Ex:Human are “intermediate hosts” to malariae parasites which multiply An intermediate host is an organism that hosts an immature parasitic stage, or a stage that reproduces asexuallyEx:Human are “intermediate hosts” tomalariae parasites which multiplyin human liver and blood cells.
12 Reservoir hosts, with respect to human parasites, are hosts that are infected with a parasite and keep it alive even if the parasite is wiped out in humans.“Reservoir hosts can spread the parasite and reintroduce it to human populations”.
13 ●A paratenic host is an organism that is infected with a parasite and can pass it on to another host, but in which the parasite does not develop further.
14 SYMBIOSISA biological relationship in which (usually) two species live in close proximity to each other and interact regularly in such a way as to benefit one or both of the organisms.*Symbiosis may exist between two or more individuals of the same species as well as between two or more individuals representing two different species
15 The three principal varieties of symbiosis are*mutualism,*commensalism,* parasitism.
16 parasite,benefit at the expense of the other MUTUALISMMutualism is any relationship between two species oforganisms that benefits both speciesCOMMENSALISMA symbiotic relationship in which one organism, thecommensal,benefits without causing any detriment tothe other organism which is the host.PARASITISMparasite,benefit at the expense of the otherorganism,which is the host.
17 Other Parasitology Definitions *A cyst is a stage of many protozoan parasites that survives well in the environment. Cysts of human parasites are infective to humans. *A trophozoite is a moving, feeding, and multiplying stage of protozoan life cycles. There are not male and female trophozoites: they multiply asexually.
18 Other Parasitology Definitions Infective (=invasive) stage The stage of the parasite that invades the host .Vector:An Arthropod which is carrying and transferring parasites from one host to an other(Egg-larval stages-adult parasite-eggs)
19 Other Parasitology Definitions Reservoir= Non-human “host” where the parasite can live.This term is only applied when the parasite can infect humans .Life Cycle= Stages of development of a parasite
20 Essential features of the parasitism *Parasite is smaller then the host*Parasite has a shorter life span than it’s host*Parasite has a greater reproductive potential than it’s host
21 Classification of parasites Zoological ClassificationLiving organismsWithout cell With celularconstruction construction(VIRUS)Procaryotic cell Eucaryotic cell(= monera) (=protista /single cell)RICKETSIA PROTOZOABACTERIA (=metazoa)HELMİNTSARTHROPODS
22 Ecological Classification Endoparasite:a parasite that inhabits theinternal organs or tissues of an animalor plantEctoparasite:any parasite that lives onthe outer surface of an animal.
23 Different location of parasites into the host body Living in digestive system - coelozoicparasites (tapeworms)Living in tissues – histozoic parasites(trichinelliosis)●Living in blood – hemoparasites (Malaria etc.).
24 Methods of invasion and escape - Via vectors- OralPenetration from the skinESCAPESputumVia vectorsFaeces or urine
25 Pathologic effects of parasites Physical trauma (skin,mucosa)MigrationNutritionToxinsImmunosupression
26 Diagnosis of Parasitic Infections: 1. Clinical diagnosis2. Laboratory diagnosis
27 Methods for study and clinical analysis Parasitological analysis:tissue samples, excrements, surgical methods (biopsy)…● Radiological (Rontgenoscopy Tomography ...)Serodiagnosis (Immunodiagnostics. ELISA test etc)
28 Major Groups of Parasites PROTOZOANS-- Single-celled eukaryotes– Malaria, Giardia, Trichomonas vaginalisHELMINTS (The Worms)– Multicellular animals– Flukes, Tapeworms, RoundwormsECTOPARASITES– Live outside the host– Ticks, Lice, Fleas
29 Treatment of Parasitic Infections: 1. Medical and surgical2. Chemotherapy3. Adequate nutrition
30 Prevention and Control: 1. Reduction in sources2. Education3. Destruction and/or control ofreservoir hosts and vector