Micro J210 Parasitology


What is a parasite?


A person who received free meals in return for amusing or impudent conversation


How are parasites classified?


- By how they move, protoza or metazoa


What is a metazoa?


-multiple cellsExamples: Helminths -worms (Tramatodes, Nematodes, Cestodes) Arthropod Vectors (External)- Arachnids, insects


What are protozoas?


-Single cellCiliats, Amoebae, Flagellates, Apicomplexans


What are the routes of infection?


-Penetration of the eyes- Acanthamoeba-Vector-borne-Tsetse fly, mosquito, arachnids-Sexual contact-Entamoeba, giardia, trichomonas-Inhalation-Acanthamoeba, Naegleria-Fecal (oral, ingestion)-Ascaris, cryptosporidium, cyclospora, entamoeba, enterobius, giardia, taenia, toxoplasma


What are amoebae?


-No defined shape-pseudopodia-most are free-livingExamples: Acanthamoeba sps, Entamoeba histolytica


What is entamoeba histolytica?


-Amoebae-Globally-Human carrier onlyTransmission: Ingestion, sexual 1. Luminal Amebiasis (Most asymptomatic)-dysentery (painful bloodly diarrhea), mucus, no fever or vomiting, teardrop ulcer in the colon.2. Invasive Extraintestinal Amebiasis: Necrotic lesions at site, liver abscesses


What is naegleria fowleri?


-Free living not obligate parasite-Direct infection through the nostrils-Inhalation: swimmers-Primary Amebic Meningoencephalitis (PAM), changes taste/smell, vominting, nausea, fever, headache, rapid onset of coma, and death in two weeks.


What are flagellates?


-locomote by single long flagellumExamples: Trypanosoma, Giardia, adn Trichomonas


Wat is Trypanosoma Brucei?


-Cattle and wild animal resovoirs-Vector Borne: Tsetse Fly-African sleeping sickness, necrotic lesion, fever (every 7-10 days), swollen lymph node, meningoencephalitis, headache, extreme drowsiness, coma, and death -Very toxic treatment


What is Trypanosoma Cruzi?


-chaga's diseaseSwelling at bite, feverl, swollen lymph nodes, CHFVector: Kissing Bug Feces


What is Giardia intestinalis/lamblia?


-Giardiasis (Diarrhea) Bever fever-pale loose, foul smelling fatty stools, fatulence, weight loss, ab pain, predisposition in immunosuppressed, homosexuals, sewage workers-Distrubution is untreated water


What is Trichomonas vaginalis?


-Most common protozoan disease, 3 billion at risk-Dwells in vulvas, vaginas, urethras and prostates of humans only-Mosty asymptomatic in men-Vaginitis in some women: odorous discharge, ab pain, dyspareunia, dysuria


What is Leishmania sps?


-Vector: female sandfuly-Animal Host-Infect and destroy macrophages-Cutaneous problems- like boils, painful skin sores


What are apicomplexas?


-Used to be called sporoza-Complicated life cycles with at least two different hosts-Examples: Plasmodium, toxoplasma


What is the plasmodium sps?


-Vector borne: female anophelse sps mosquite4 Species: P. Falciparum, vivax, ovale, malariae-Over 400 million infection3 stages:-Liver: Vivax and Ovale remain dorman here for years, recurring-Blood Cycle: feed on RBC, fever on cell rupture-Mosquito cycle: ingest sexually active form from RBC, which mature in the gutSymptoms: Recurrent fever, chills, diarrhea, headache, hemolytic anermia, jaundice


What is P.falciparum?


-Worst type of malariaBlack water fever: extreme cell lysis, dark urine and kidney failureCerebral malaria: hemorrhage in teh brain from inelastic RBC


What are protective conditions of malaria?


Sickle cell trait- sickling RBC resist penetrationHemoglobin C- mishapen RBC resist penetration-Glucose 6 phosphate dehydrogenase deficieny-needed for parasite DNA synthese-Lack of duffy antigens- resistance to P. vivax


What is toxoplasma gondii?


-About 40% of US population is exposed-Animal host-cat-Fecal-oral transmission, inhalation-Selfl limiting except in fetus and AIDS patients-Asympathetic, spastic paralysis, blindness, brain infection


What are intermediate hosts and definitive host?


Intermediate: Larval/ immature formDefinitive: adult forms, large # of eggs


What is W.bancrofti?


-Vector borne-transmitted by female mosquitoes-Infests sub Q tissue and lymphatics causing filariasis-Can result in elephantiasis,which is not reversible-Secondary bacterial infections


What is Ascaris lumbricodies?


-Most common ringwormLargest nematode-Fecal oral route: egg, intestine, larvae, lung, larvae 2, intestine, adult-Fever, dry cough, ab pain, obstruction, eosinophilia, nausea, vomiting, asthma, worm emigrations,no diarrhea


What is enterobius vermicularis?


-PinwormWorldwide, most common worm in US-Itchy bottom, tape testFecal oral colon: nocturnal laying of eggs


What are cestodes?


-Tapeworms-Flat, segmented, ong intestingal parasites-Scolex for attachment, cuticle-Multiple hosts, humans are definitive host-Fecal oral transmisisonTaenia saginate: beef tapewormTaenia Solium: pork tapewormAsymptomatic, nausea, ab pain, diarrhea, blockage, neurolgocial and ocualr symptoms by T. solium larvae