Introduction to Parasites 1 Flashcards
<p>What is a parasite?</p>
<p>An organism that lives in another organism (host) and gets its food at the expense of the host</p>
<p>How does the complexity of parasites compare to bacteria?</p>
<p>They are simple organisms but more complex than bacteria</p>
<p>What do parasites cause?</p>
<p>Many diseases with malaria causing the most deaths globally</p>
<p>What are the 3 classes of parasites?</p>
<p>Protozoa</p>
<p>Helminths (worms)</p>
<p>Arthropods</p>
<p>What are examples of protozoa?</p>
<p>Malaria</p>
<p>Amoebae</p>
<p>Flagellate</p>
<p>Leishmaniasis</p>
<p>How is malaria spread?</p>
<p>By mosquito</p>
<p>What are symptoms of amoebae?</p>
<p>Diarrhoea with blood/pus and cysts formed in stool</p>
<p>What does leishmaniasis cause?</p>
<p>Skin or mucosal ulceration</p>
<p>Leads to fever and weight loss</p>
<p>How does leishmaniasis spread?</p>
<p>Bite by sandflies</p>
<p>How is leishmaniasis diagnoses?</p>
<p>Histology of biopsy material</p>
<p>What are examples of helminths?</p>
<p>Roundworms (nematodes)</p>
<p>Tapeworms (cestodes)</p>
<p>Flukes (trematodes)</p>
<p>What is the scientific name of roundworms?</p>
<p>Nematodes</p>
<p>How are nematodes diagnosed?</p>
<p>Pressing adhesive tape againt perianal region in the morning</p>
<p>Where are nematodes ova seen?</p>
<p>In microscopy</p>
<p>How are nematodes transmitted?</p>
<p>Faecal-oral route</p>
<p>What is a common nematode and what does it do?</p>
<p>Ascaris lumbricoides which is a mass of worms that may obstruct the intestine or bile duct</p>
<p>What are common cestodes?</p>
<p>Taenia saginata (beef)</p>
<p>Taenia solium (pork)</p>
<p>How do cestodes spread?</p>
<p>Larvae cysts ingested in meat</p>
<p>Where are cestodes ova seen?</p>
<p>In stool</p>
<p>What is a species of cestodes carried by dogs and transmitted by humans ingesting eggs?</p>
<p>Echinococcus spp</p>
<p>What is the scientific name of flukes?</p>
<p>Tramatodes</p>
<p>What is the scientific name of tapeworms?</p>
<p>Cestodes</p>
<p>What are common kinds of trematodes?</p>
<p>Schistosomes species:</p>
<p></p>
<p>S.haematobium (bladder)</p>
<p>S.mansoni (intestinal)</p>
<p>S.japonicum (intestinal)</p>
<p>Where are high rates of trematodes found?</p>
<p>Near fresh water</p>
<p>What is an important thing in the life cycle of trematodes?</p>
<p>Snails</p>
<p>What are examples of arthropods?</p>
<p>Lice</p>
<p>Ticks</p>
<p>Mites</p>
<p>What are protozoa?</p>
<p>Microscopic once celled organisms that can be free living or parasitic in nature</p>
<p>How are protozoa transmitted?</p>
<p>Faecal-oral route (live in human intestine)</p>
<p>Arthropod vector (live in blood or tissue)</p>
<p>Where do protozoa that are transmitted by the faecal-oral route live?</p>
<p>Human intestine</p>
<p>Where do protozoa that are trasmitted by a arthropod vector live?</p>
<p>Blood or tissue</p>
<p>What is the life cycle of malaria?</p>
<p>1) Sprozoites injected under skin by mosquito</p>
<p>2) Travels through blood and enters liver</p>
<p>3) Matures in liver and re-enters circulation at merozoites</p>
<p>4) Invade red cells, multiply and lyse cells</p>
<p>What is the life cycle of schistosomiasis?</p>
<p>1) Miracidia released in fresh water</p>
<p>2) Penetrate body of snail</p>
<p>3) Cercaria emerge from snail after 4-6 weeks</p>
<p>4) Penetrate human skin</p>
<p>5) Travel from lungs to liver</p>
<p>6) Mature in liver into worms (schistosomes) that migrate to the bladder venules</p>
<p>7) Lay eggs that cause inflammation</p>
<p>When does a definitive diagnosis of a parasite happen?</p>
<p>Once the parasite is identified in host tissue or excreta</p>
<p>What are the different stages present in microscopy?</p>
<p>Parasites</p>
<p>Cysts</p>
<p>Ova</p>
<p>What is rarely possible for parasites?</p>
<p>Culture</p>
<p>What is used to diagnose malaria?</p>
<p>Blood films</p>
<p>What is serology?</p>
<p>Detection of antibodies</p>
<p>Is serology used to detect parasites?</p>
<p>Yes it can be useful, especially for parasites in deep tissue</p>
