W4 Fundamentals of Medical Protozoology (Adebiyi).pdf

STUDENT OUTCOMES OVERVIEW FUNDAMENTALS OF MEDICAL PROTOZOOLOGYADERSHIP CONFERENCE AND A THIRD LINE IF YOU WANT Raymond F Adebiyi Professor Immunology and Medical Microbiology Learning Objectives 1. Given the name of a parasite, state if it is a protozoon or a helminth. 2. Recall the scientific and c...

STUDENT OUTCOMES OVERVIEW FUNDAMENTALS OF MEDICAL PROTOZOOLOGYADERSHIP CONFERENCE AND A THIRD LINE IF YOU WANT Raymond F Adebiyi Professor Immunology and Medical Microbiology Learning Objectives 1. Given the name of a parasite, state if it is a protozoon or a helminth. 2. Recall the scientific and common names for each parasite. 3. Describe the parasitic form that causes disease in humans (the infective form). 4. Identify the body site where the parasite is primarily located. 5. Describe the mode of infection for each parasite. 6. Describe and state the name of the disease caused by each parasite. 7. State the appropriate specimen to be examined and describe the laboratory tests that may be of value for diagnosis. 8. Describe the life cycle of each parasite. 9. Given a case scenario, name the most probable parasite involved and discuss the method(s) for making a diagnosis. 10. Discuss the main features of immunological responses to protozoal and helminthic infections. RFA OFFICE HOURS Please check Canvas calendar https://atge.webex.com/meet/radebiyi email: [email protected] Dr R F Adebiyi CDC More than 300,000 people living in the United States are infected with Trypanosoma cruzi. There are at least 1,000 hospitalizations for symptomatic cysticercosis per year in the US. At least 14 percent of the U.S. population has been exposed to Toxocara. More than 60 million people in the United States are chronically infected with Toxoplasma gondii. The Trichomonas parasite is extremely common, affecting 3.7 million people in the United States. ROSS UNIVERSITY SCHOOL OF M EDICINE | 4 ROSS UNIVERSITY SCHOOL OF MEDICINE Parasite Life Cycles The study of each life cycle is important to determine (1) the mode of infection and the form of the parasite that causes human infection (2) the disease that is caused by the parasite and the primary body site that is affected and (3) the means of making a definitive diagnosis. Dr R F Adebiyi Parasitology ▪ Protozoa unicellular organisms -the first ‘animals’ ▪ Metazoa (Helminthes) multicellular organisms Dr R F Adebiyi Protozoa Classification Amoebae (rhizopoda, sarcodina) pseudopodal motility Flagellates (mastigophora) flagellate motility Ciliates (ciliata) cilia assisted motility Sporozoa (sporozoa) gliding motility Dr R F Adebiyi Typical Fecal-Oral Life Cycle excystation CYST Passed in feces Resistant Ineffective encystment TROPHOZOITE Feeding Motile Replication Entamoeba histolytica Amoebiasis World-wide distribution poor sanitary conditions Modes of transmission contaminated water (food) hand-mouth sexual Site of infection intestine may become extraintestinal (liver abscess, etc.) Diagnosis cysts in feces Dr R F Adebiyi Entamoeba histolytica Entamoeba histolytica trophozoite Dr R F Adebiyi Entamoeba histolytica cyst Dr R F Adebiyi Other Intestinal Amebas Dr R F Adebiyi Intesinal Flagellate Giardia lamblia Giardia intestinalis Giardia duodenalis Giardiasis Mode – ingestion of cysts (outdoor water; spring) Site – intestine only Diagnosis – cysts in feces Dr R F Adebiyi Giardiasis Intestinal Ciliate Balantidum coli Common parasite of animals (pig) Balantidiasis Mode – ingestion of cysts Site – intestine Diagnosis – cysts in feces Dr R F Adebiyi Intestinal Ciliate Dr R F Adebiyi INTESTINAL SPOROZOA Isosporiasis-Cyclosporiasis-Cryptosporidiosis Cystoisospora belli Cyclospora cayetanensis Cryptosporidium parvum/ hominis Dr R F Adebiyi Intestinal Sporozoa Mode ingestion of oocyst (water, food, swimming pool) Site infection of intestinal epithelium self limiting in immunocompetent persons sporogony/schizogony (sexual / asexual stages) Diagnosis – Acid-fast oocyst in feces Dr R F Adebiyi Urogenital Flagellate Trichomonas vaginalis trichomoniasis -world wide occurrenceMode – direct sexual contact Site – vagina, urethra Diagnosis – wet mount of vaginal smear to show rapidly motile trophozoites - no cysts are formed Urogenital Flagellate Dr R F Adebiyi Amoeboflagellates (Primary Cns Pathogens) Naegleria fowleri -more aggressiveMode – infection of nasal passages (swimming/diving) Site – CNS (amoebic meningoencephalitis) Diagnosis – trophozoite in CSF Acanthamoeba culbertsoni -less aggressiveMode – infection of skin, eye, lungs and other tissue especially in immunocompromised persons, may spread through blood to the CNS (granulomatous encephalitis). Amoeboflagellates (Primary Cns Pathogens) Dr R F Adebiyi Haemoflagellates Trypanosoma & Leishmania Insect-borne flagellates found in blood, tissue, lymph and CSF amastigote (tissue) promastigote epimastigote trypomastigote (blood plasma) Dr R F Adebiyi Hemoflagellates African tryponosomiasis (sleeping sickness) Trypanosoma gambiense Trypanosoma rhodesiense American trypanosomiasis (Chagas’ disease) Trypanosoma cruzi Leishmania Leishmania tropica Leishmania brasiliensis Leishmania donovanii Dr R F Adebiyi Trypanosoma Vectors ❖T. gambiense tsetse fly, West Africa ❖T. rhodesiense tsetse fly, East Africa ❖T. cruzi reduviid bug, Americas Dr R F Adebiyi Trypanosoma Dr R F Adebiyi TRYPANOSOMA (trypomastigote in blood plasma) Dr R F Adebiyi Trypanosoma Trypanosoma cruzi American trypanosomiasis Chagas’ disease (enlarged heart and intestine) Vector: reduviid bug (Triatoma) ‘kissing bug’ ‘triatomine bug’ Dr R F Adebiyi Trypanosoma Dr R F Adebiyi Leishmania Vector – Phlebotomus sand fly 3 basic forms of disease 1. 2. 3. Leishmania tropica – dermal/cutaneous form (mildest) Leishmania brasiliensis – mucocutaneous form Leishmania donovanii – visceral form (most severe) -amastigotes found within macrophages in all forms of the diseaseDr R F Adebiyi Tissue Sporozoa Plasmodium spp. (blood & tissue) malaria Babesia spp. (blood) babesiosis Toxoplasma gondii (tissue) toxoplasmosis Dr R F Adebiyi Tissue Sporozoa Plasmodium Babesia Toxoplasma Sporozoa – two life cycles, two hosts Sexual (sporogony) – definitive host Asexual (schizogony) – intermediate host Dr R F Adebiyi Malaria Vertebrate: intermediate host Mosquito: definitive host 1. sporozoite 2. merozoite 3. schizont 4. gametocyte Dr R F Adebiyi Malaria Dr R F Adebiyi Babesiosis ▪ ▪ ▪ ▪ easily confused with malaria Babesia microti Babesia divergens Tick vector (Ixodes) same vector of Lyme disease Dr R F Adebiyi Toxoplasmosis Toxoplasma gondii ▪ world wide prevalence ▪ intermediate hosts: man, cattle, rodent, etc. ▪ definitive host: cat family Dr R F Adebiyi Toxoplasmosis MODES OF TRANSMISSION ingestion of infected meat ingestion of oocyst in food ingestion of oocyst on hand, nail organ transplantation blood transfusion accidental inoculation inhalation transplacental Dr R F Adebiyi Toxoplasmosis Dr R F Adebiyi THE END Dr R F Adebiyi