Parasitology PDF

Parasitology 2. Parasite Organism that lives within or lives on the host I. Introduction Endoparasite...

Parasitology 2. Parasite Organism that lives within or lives on the host I. Introduction Endoparasite o Lives within Ectoparasite A. Symbiosis o Lives on Any close association between 2 organisms Mutualism o Both organisms benefit II. Protozoans Commensalism Unicellular, Eukaryotic organism o One organism benefit while the other is 2 general stage unharmed o Cyst Parasitism o Trophozoite o One organism benefit while other is harmed A. Cyst B. Host parasite Non – motile Non – feeding 1. Host Infective stage Organism who harbors the parasite Support growth and/or reproduction B. Trophozoite Feeding, pathogenic stage Motile (organ of locomotion / OOL) Types Final / Important for the sexual stage of C. Groups Definitive host parasite life cycle Intermediate Temporary environment for 1. Amoeba (Sarcodina) host other stages of parasite life OOL: Pseudopods cycle Paratenic host Not important for the life cycle of Entamoeba histolytica parasite but important for the Clinical amoebiasis parasite to reach its definitive VF host (transfer host) Intestinal o Hyaluronidase o Amoebic dysentery o Flask – shaped ulcers Amoebic liver abscess → aspirate Extraintestinal anchovy sauce material (blood pus, necrotic liver tissue)  Treatment Vector Transmitted Flagellates Luminal Intestinal Amoebicides Iodoquinol Trypanosoma Diloxanide furoate Gambience (west) o (DOC for Asx amoebiasis, Rhodesiense (east) carriers) Vector Paramomycin sulfate T. brucei o Tse – tse fly (Glossina sp.) [MOA] - Unknown Clinical Tissue Metronidazole o African sleeping sickness Amoebicide [MOA] o Peripheral (blood) o activated in anaerobic o CNS (brain) environment → reduced nitro WaGER | PEMS group → inh. DNA synthesis  Wa  G  E  R [Use] West Gambience East Rhodesiense o Anaerobic infection and Protozoal infections  P  E  M  S Pentamidine Eflornithine Melarsoprol Suramin [SE] o Metallic after taste and Disulfiram like reactions Vector Chloroquine o Rheduvid (kissing bug) o For amoebic ulcer abscess Clinical T. cruzi o American sleeping sickness Emetin and Dihydroemetin (Chagas disease) [MOA] Tx o Inh. CHON synthesis o Nifurtimox (CDC) o Benznidazole (Brazil) 2. Flagellates (Mastigophora) OOL: Flagella Leishmania Intestinal Flagellates [Treatment] – Na Stibogluconate Gardia Trophozoite Vector lamblia o Old man with eyeglasses o Phlebotomus sandfly Pathogenesis L. tropica Clinical o Carpets the intestinal lumen o Cutaneous / old worlds Clinical leishmaniasis o Giardiasis o Oriental sore (Cool tropics) o Traveler’s diarrhea Vector (Leningrad’s Curse) o Phlebotomus sandfly o ETEC: Montezuma’s revenge Clinical Dx L. brasiliensis o Mucocutaneous o Fecalysis (cyst) o Espundia o String test / Enterotest o New world leishmaniasis Tx (MEN in Brazil) o Metronidazole Vector o Phlebotomus sandfly Sexually Transmitted Flagellates L. donovani Clinical Trichomonas Clinical o Visceral leishmaniasis vaginalis o Trichomoniasis o Kala – azar o Males – Asx o Females – vaginal discharge / 3. Ciliates (Ciliosphora) Vaginitis OOL: Cilia Tx Balantidium coli o Metronidazole (ping – ping o Largest intestinal protozoa parasitizing infection) man o Reservoir ▪ Pigs o Clinical ▪ Balantidiasis → diarrhea ▪ Barrel shaped ulcers o Tx – Metronidazole  4. Coccidia Chloroquine DOC for prophylaxis and Tx of Non – motile malaria EXCEPT chloroquine Opportunistic infection resistant falciparum MOT Primaquine For radical cure of P. vivax and P. o Fecal – oral route ovale Kill hypnozoites Coccidia Mefloquine DOC for prophylaxis of chloroquine Toxoplasma Reservoir resistant falciparum gondii o Cats Pregnancy Clinical Doxycycline DOC for the prophylaxis of o Toxoplasmosis → CNS multidrug resistant falciparum (confusion, seizures) Fansidar Sulfadoxine + Pyrimethamine Tx 2nd line agent o Daraprim Malarone Atovaquone + Proguanil ▪ Sulfadiazine + 2nd line agent Pyrimethamine Atovaquone Cytosporidium Acquired drinking infected water o Inhibit ETC and collapses Clinical mitochondrial membrane o Cryptosporidiosis → diarrhea potential (AIDS) Proguanil Tx o Inhibit dihydrofolate reductase o Nitazoxanide and thymidine Co – Artem Artemether + Lumefantrine 5. Sporozoa DOC for treatment of chloroquine Non – motile resistant falciparum Arthropod – borne Artemether o Forms toxic heme products in Plasmodium sp the food vacuole Vector Lumefantrine o Female Anopheles mosquito (night biter) o Unknown Infective stage to man 𝑠𝑝𝑜𝑟𝑜𝑧𝑜𝑖𝑡𝑒 → 𝑙𝑖𝑣𝑒𝑟 → ℎ𝑦𝑝ℎ𝑜𝑧𝑜𝑖𝑡𝑒 III. Helminths 𝑏𝑙𝑜𝑜𝑑 𝑅𝐵𝐶 𝑏𝑙𝑜𝑜𝑑 Multicellular 𝑙𝑖𝑣𝑒𝑟 𝑡𝑟𝑜𝑝ℎ𝑜𝑧𝑜𝑖𝑡𝑒 𝑠𝑐ℎ𝑖𝑧𝑜𝑖𝑡 𝑔𝑎𝑚𝑒𝑡𝑜𝑐𝑦𝑡𝑒𝑠 → 𝑚𝑜𝑠𝑞𝑢𝑖𝑡𝑜 Eukaryotic A. Nematodes Clinical: Malaria Intestinal Nematodes P. falciparum Malignant tertian malaria, sub Ascaris Giant intestinal roundworm tertian malaria lumbricoides MOT Endemic in the Philippines o Fecal – oral route (eggs) G6PD deficiency (Protective) Clinical P. malariae Quartan malaria o Ascaris P. vivax and Benign tertian malaria ▪ Ascaris pneumonitis P. ovale ▪ Intestines: Obstruction, perforation, occlusion Relapse Malaria Enterobius Pinworm Recurrence From hypnozoites (P. ovale and vermicullaris MOT P. vivax) o Fecal – oral route Recrudescence RBCs trapped in capillary o Inhalational Clinical Treatment o Enterobiasis o Nocturnal pruritus ani Quinolones [MOA] – unknown → prevent o Rectal prolapse polymerization of heme to hemozoin Dx storage o Fecalysis Quinidine [MOA] – unknown → prevent o Scotch tape swab polymerization of heme to hemozoin o D shaped under microscope storage Trichuris Whipworm Treatment trichiura MOT o Fecal – oral route (TAE) Benzimidazoles Clinical MOA o Trichuriasis / GI s/sx o Binds to  - tubulin → inhibits microtubule Ancylostoma Hookworm polymerization (microtubule -  absorption duodenale MOT with fatty food) (old world) o Skin penetration of Filariform Abendazoles DOC for Nematodal infections, larva cysticercosis hydatid disease Necator Clinical Mebendazoles DOC for Whipworm Infection americanus o Cutaneous larva migrans Thiabendazole DOC for Threadworm infection (new world) o Hookworm pneumonitis o Intestine ▪ Iron deficiency anemia Pyrantel MOA Strongyloides Threadworm Pamoate o Neuromuscular blocking agent → paralysis to worms stercovalis MOT DOC o Skin penetration of filariform o Pinworm infection larva Diethyl MOA Clinical o Strongyloidiasis carbamazine o Immobilizes microfilaria and alters their surface structure o Larva currens o More susceptible to immunity o Pneumonitis ▪ GI s/sx DOC o Filariasis (BCDEF) Capillaria MOT Ivermectin MOA philippinensis o Ingestion of infected fish (Bagsti and Birut) o Intensifies GABA – mediated Clinical signals → flaccid paralysis (GHI) o Capillariasis ▪ GI s/sx DOC o Eyeworm infection Tissue Nematodes (onchocerciasias) Trichinella spiralis Muscle roundworm o Mazzotti reaction MOT Diperazine MOA o Ingestion of encysted o Cause paralysis by blocking larva from undercooked ACh in NMJ pork o Alt. agent for ascariasis Clinical o Trichinosis / trichinellosis o GI s/sx → muscle pain B. Platyhelminths (Flatworms) Toxocara canis MOT Cestodes (Tapeworms) (dog roundworm) o Fecal – oral route Clinical Diphyllobotrium Broadfish tapeworm Toxocara cari o Toxocariasis → visceral latum Clinical (cat roundworm) larva migrans → eyes, o Diphyllobothriasis liver, CNS o Vit B12 deficiency (megaloblastic anemia) Vector Transmitted Nematodes Taenia solium Pork tapeworm Microfilarial Wuchucheria bancrofti Clinical worms Brugia malayi o Taeniasis → GI s/sx Vector o Cysticercosis (larva) → muscle and CNS o Aedes aegypti Clinical Taenia Beef tapeworm o Filariasis → elephanthiasis saginata Clinical Eyeworms River blindness (onchocerciasis) o Taeniasis → GI s/sx Loaloa (African eyeworm) Hymenolepsis Dwarf tapeworm Onchocerea nana MOT o Vector – Black fly volvulus o Ingestion of infected insects Clinical o Hymenolepsiasis → GI s/sx Echinococcus Dog tapeworm o Acute – Katayan fever → GI granulosus MOT s/sx, liver enlargement o Fecal – oral route o Chronic Clinical ▪ S. japonicum / S. mansoni o Hydatid disease – liver cirrhosis / fibrosis o Asx → liver and respiratory ▪ S. haematobium – urinary s/sx bladder cancer Trematodes (Flukes) Treatment Hermaphroditic Praziquantel MOA Fasciolopsis Giant intestinal fluke o  permeability of cell buski MOT membrane to calcium o Ingestion of water chesnut (“qualicium”) infected with metacercaria DOC Clinical o For cestodal and trematodal o Fasciolopsiasis infection o GI s/sx Bithionol MOA Fasciola Giant / sheep liver fluke o Unknown hepatrea MOT DOC o Ingestion of watercress o For fascioliasis (kangkong) Niclosamide MOA Clinical o Inh. Oxidative phosphorylation o Fasciliasis and stimulates ATPase o GI s/sx Alt. agent for cestodal and Echinostoma MOT trematodal infection ilocanum o Ingestion of snails (Pila Diperazine MOA luzonica) o Inh. AChase → spastic Clinical paralysis o Echinostomiasis / Garrison’s Alt. agent for S. haematobium fly → GI s/sx Oxamniquine MOA Clonorchis Oriental liver fluke o Unknown sinensis MOT Alt. agent for S. mansoni o Ingestion of infected fish Clinical o Clonorchiasis → GI s/sx Paragonimus Oriental lung fluke westermani MOT o Ingestion of Crab Clinical o Paragonomiasis → GI s/sx → respiratory s/sx Dx – Sputum examinator Schistosoma Not hermaphroditic sp Dx o Kato – Katz smear S. japonicum o Rudimentary lateral spine S. haematobium o Prominent terminal spine S. mansoni o Prominent lateral spine MOT o Skin penetration of cercaria from snails Clinical o Schistosomiasis o Swimmer’s itch