MUST TO KNOW IN PARASITOLOGYSymbiosis Living together of unlike organisms Commensalism 2 species live together One species benefits from the relationship w/o harming or benefiting the other Ex. Entamoeba coli Mutualism 2 organisms benefit from each other Ex. Termites and the flagellates inside their digestive system Parasitism 1 organism lives in or on another for its survival at the expense of the host Ex. Entamoeba histolytica Endoparasite Lives inside the body of the host “Infection” Ectoparasite Lives outside the body of the host “Infestation” Erratic Parasite found in an organ w/c is not its usual habitat Obligate parasite Need a host to complete their development Facultative parasite May exist in a free-living state May become parasitic when the need arises Accidental/incidental Parasite that established itself in a host where it does not ordinarily live parasite Ex. Echinococcus granulosus Permanent parasite Remains on or in the body of the host for its entire life Temporary parasite Lives on the host only for a short period of time Spurious parasite Free-living organism Passes through the digestive tract w/o infecting the host Definitive/final host Parasite attains sexual maturity Intermediate host Harbors the asexual/larval stage of the parasite Paratenic host One in which the parasite does not develop further to later stages Parasite remains alive and is able to infect another host Reservoir host Allows the parasite’s life cycle to continue and become additional sources of infection Biologic vector Transmits the parasite only after the the latter has completed its development within the host Ex. Aedes mosquito Mechanical/phoretic vector Only transports the parasites Ex. Flies and cockroach Epidemiology Study of patterns, distribution and occurrence of disease Incidence Number of new cases of infection in a given period of time Prevalence (%) Number of individuals estimated to be infected w/ a particular parasite Cumulative prevalence % of individuals in a population infected w/ at least 1 parasite Intensity of infection Number of worms per infected person (Worm burden) Morbidity Clinical consequences of infections or diseases that affect an individual’s well- being Deworming Use of antihelminthic drugs in an individual Cure rate (%) Number of previously positive subjects found to be egg-negative Egg reduction rate % fall in egg counts after deworming Selective treatment Individual-level deworming Targeted treatment Group-level deworming Universal treatment Population-level deworming Coverage Proportion of the target population reached by an intervention Efficacy Effect of a drug against an infective agent Effectiveness Measure of the effect of a drug against an infective agent lec.mt 04 |Page | 112 Information-education- A health education strategy that aims to encourage people to adapt and communication maintain healthy life practices Environmental Planning, organization, performance, and monitoring of activities for the management modification and/or manipulation of environmental factors Environmental sanitation Interventions to reduce environmental health risks Sanitation Provision of access to adequate facilities for the safe disposal of human excreta Eradication Permanent reduction to zero of the incidence of infection caused by a specific agent, as a result of deliberate efforts Elimination Reduction to zero of the incidence of a specified disease in a defined geographic area as a result of deliberate efforts Protozoan Unicellular organism Metazoan Multicellular organism Classification of Protozoan Parasites Sarcomastigophora Sarcodina Acanthamoeba Endolimax Entamoeba Iodamoeba Naegleria Mastigophora Chilomastix Dientamoeba Giardia Trichomonas Leishmania Trypanosoma Ciliophora Balantidium Apicomplexa Babesia Cryptosporidium Cyclospora Isospora Plasmodium Toxoplasma Microspora Enterocytozoon Encephalitozoon Vittaforma Trachipleistophora Pleistophora Brachiola Microsporidium Classification of Metazoan Parasites Nematoda Intestinal Ascaris Capillaria Enterobius Hookworm Strongyloides Trichuris Extraintestinal Angiostrongylus Filarial worms Trichinella lec.mt 04 |Page | 113 Cestoidea Cyclophyllidea Dipylidium Echinococcus Hymenolepis Raillientina Taenia Pseudophyllidea Diphyllobothrium Spirometra Trematoda Artyfechinostomum Clonorchis Echinostoma Fasciola Fasciolopsis Heterophyids Opisthorchis Paragonimus Schistosoma Arthropoda Arachnida Mites Scorpions Spiders Ticks Chilopoda Centipedes Crustacea Copepods Crabs Diplopoda Millipedes Insecta Flies Flea Beetle Bees Lice Wasp Bugs Mosquitoes Pentastomida Tongue worms Common/Other Names Ascaris lumbricoides Giant intestinal roundworm Lumbricus teres Enterobius vermicularis Pinworm Oxyuris vermicularis Seatworm Social or Society worm Trichuris trichiura Whipworm Capillaria philippinensis Pudoc worm Necator americanus American hookworm American murderer New world hookworm Ancylostoma duodenale Old world hookworm Ancylostoma braziliense Cat hookworm Ancylostoma caninum Dog hookworm Strongyloides stercoralis Threadworm lec.mt 04 |Page | 114 . trichiura E.mt 04 |Page | 115 . lumbricoides T. philippinensis Filariform larva Hookworm S. vaginalis Sporozoites Plasmodium Trypomastigote Trypanosoma Promastigote Leishmania Embryonated egg “HATE” H. bancrofti B.Trichinella spiralis Muscle worm Garbage worm Wuchereria bancrofti Bancroft’s filarial worm Brugia malayi Malayan filarial worm Loa loa Eye worm Onchocerca volvulus Blinding worm Dirofilaria immitis Dog/canine heartworm Dracunculus medinensis Guinea worm Fiery serpent of the Israelites Medina worm Dragon worm Anisakis Fish and Marine mammal roundworm Herring’s worm Toxocara canis Dog ascarid Toxocara cati Cat ascarid Fasciola hepatica Sheep liver fluke Fasciola gigantica Giant liver fluke Clonorchis sinensis Oriental liver fluke Chinese liver fluke Fasciolopsis buski Giant intestinal fluke Echinostoma ilocanum Garrison’s fluke Heterophyes heterophyes Von Siebold’s fluke Paragonimus westermani Oriental lung fluke Schistosoma japonicum Oriental blood fluke Schistosoma mansoni Profile of a man Schistosoma haematobium Bladder fluke Taenia saginata Beef tapeworm Taenia solium Pork tapeworm Hymenolepis nana Dwarf tapeworm Hymenolepis diminuta Rat tapeworm (Norway rats) Dipylidium caninum Dog tapeworm Double-pored tapeworm Diphyllobothrium latum Broadfish tapeworm Echinococcus granulosus Hydatid worm Infective Stages Cyst Protozoans (amoebas) Trophozoite T. stercoralis 3rd stage larva (filiform) W. malayi lec. nana A. vermicularis Larva T. spiralis C. hepatica F. Trichuris Ascaris lumbricoides Characteristics Resembles common earthworm Fertilized Egg 3 layers: -Inner: Vitelline membrane -Middle: Glycogen layer -Outer: Mammilation (corticated) lec. Hookworms Large intestines “ET”: Enterobius. bancrofti B. curved tail Life cycle Egg stage > Larval stage > Adult stage Aphasmids Lacks phasmids or caudal chemoreceptors “TCT”: Trichuris-Capillaria-Trichinella Phasmids w/ caudal chemoreceptors Hookworm S. Ascaris. loa O. felineus P. japonicum S. Trichuris Heart-to-lung migration “ASH”: Ascaris. volvulus Mansonella Cercaria S. saginata Cysticercus cellulosae T. ilocanum Heterophyids Cysticercus bovis T. Hookworm Extraintestinal Nematodes Filarial worms = lymphatics and subcutaneous tissues T. sinensis O. cantonensis = meninges Visceral Larva Migrans T. mansoni Metacercaria F. cantonensis L. Strongyloides. A. westermani E. caninum Nematodes (Roundworms) Separate sexes Female = larger. latum Hydatid cyst E. spiralis = muscles A. stercoralis W. pointed tail Male = smaller. granulosus Cysticercoid larva H. Ascaris. Strongyloides. solium Plerocercoid larva D. diminuta D. malayi Amphid Cephalic chemoreceptors Oviparous Lays eggs in unsegmented stage (unembryonated) Ovoviviparous/oviviparous Lays eggs in segmented stage (embryonated) Viviparous/larviparous Larva Frequency “EAT”: Enterobius > Ascaris > Trichuris Small intestines “CASH”: Capillaria. canis and T. cati Triad of infection/Unholy 3 “HAT”: Hookworm. haematobium S.mt 04 |Page | 116 . buski C. Diagnosis 1. No infection b.Unfertilized Egg 2 layers: -Inner: Glycogen -Outer: Mammilation Has lecithin granules Adult Buccal cavity: Triangular. SS) External autoinfection Egg Elongated. GL) Borborygmi = peculiar abdominal gurgling sound lec.mt 04 |Page | 117 . trilobate lips MOT Ingestion Symptoms and Pathology Larval migration: Eosinophilia (resembles Loeffler’s syndrome) Adult: Erratic Extraintestinal sites Intestinal perforation Lab. Stool exam = Egg: Diagnostic stage Capillaria philippinensis Characteristics Causes pudoc disease or mystery disease Egg w/ bipolar mucus plugs that are not as protruded as T. flattened on 1 side D-shaped Adult w/ lateral wings or cephalic alae MOT Ingestion Symptoms and Pathology Mother’s complex: -Pruritus ani -Lack of sleep -Extraintestinal enterobiasis Lab. Early infection c. Perianal swab: Scotch tape swab = Egg: Diagnostic stage Trichuris trichiura Characteristics Causes trichocephaliasis Egg Barrel-shaped w/ bipolar mucus plug Resembles Japanese lantern Adult Slender or attenuated in the anterior Resembles a whip MOT Ingestion Symptoms and Pathology Rectal prolapse (Heavy infection) Lab. Diagnosis 1. trichiura egg Guitar. Diagnosis 1. peanut-shaped Adult Male: w/ chitinized spicule (spicule sheath) Female: have eggs in utero MOT Ingestion of freshwater fishes IH Fresh water fishes: -Hypselotris bipartite (ipon) -Birot -Bagsang -Bagtu Symptoms and Pathology Malabsorption (CP. All MALE WORM infection Enterobius vermicularis Characteristics Autoinfection: Same host (EV. Stool exam = Egg: Diagnostic stage = If (-) stool exam: a. Harada Mori Culture technique = Filter paper culture technique = For hookworm and threadworm larvae 3. Ancylostoma) Characteristics Agent of laziness in poor white population and tropical anemia in Puerto Rico Egg Same for all species Ovoidal. w/ semilunar cutting plates A.mt 04 |Page | 118 . Diagnosis 1. Diagnosis 1. thin-shelled. Baermann funnel technique (Strongyloides) Strongyloides stercoralis Characteristics Causes Cochin-China diarrhea Facultative nematode: -Parasitic: small intestine -Free-living: soil Adult Female: capable of parthenogenesis (fertilization w/o the benefit of male) Rhabditiform larva Buccal cavity: short Genital primordium: prominent or conspicuous Filariform larva Sheath: (-) Tail: Notched MOT Skin penetration Symptoms and pathology Skin: Allergic reaction Larval migration: pneumonia Intestines: abdominal pain. w/ 2 pairs of teeth Male copulatory bursa: -Bipartite (2 digits): Barbed & bristle like -Tripartite (3 digits): Simple & not barbed Rhabditiform larva 1st stage larva Short and stout Open mouth: feeding stage Buccal cavity: long Genital primordium: small or inconspicuous Filariform larva 2nd stage larva Long and slender Closed mouth: nonfeeding stage Sheath: (+) Tail: Pointed MOT Skin penetration Symptoms and Pathology Mazza Mora/Water sore or ground itch Severe itching/allergic reaction at the site of skin penetration IDA Cutaneous larva migrans (Creeping eruption): A. caninum (animal hookworm) Lab. diarrhea. americanus: S-shaped. Stool exam = Egg: Diagnostic stage 2. colorless “Morula ball” Adult N. LBM alternating w/ constipation Lab. duodenale: C-shaped. braziliense and A. vomiting Trichinella spiralis Characteristics Adult: in intestines Larva: in muscles lec. Stool exam = Egg: Diagnostic stage Hookworms (Necator. Requires 2 host to complete its life cycle Propagated by black and brown rats Man: both DH and IH. Diagnosis 1. EG) b. Muscle biopsy = Encysted larva: Diagnostic stage 2. diarrhea Lab. TC) = Beck’s albino rats/mice Filarial Worms Characteristics Vector-borne nematodes DH: man (IS: filiform larva/3rd stage larva) IH: vector (IS: microfilaria) DS: Microfilaria Adults In lymphatics and subcutaneous tissue Microfilaria In blood Lab.mt 04 |Page | 119 . Immuno-tests: a. Knott’s technique = Isolation of microfilaria = Blood + formalin + Giemsa stain Wuchereria bancrofti Habitat Lymphatics Vector Aedes Anopheles Specimen Blood Microfilaria Sheathed Nuclei absent in tail Periodicity Nocturnal (10PM-2AM) Brugia malayi Habitat Lymphatics Vector Mansonia Specimen Blood Microfilaria Sheathed Tail w/ 2 separate nuclei Periodicity Subperiodic Nocturnal Loa loa Habitat Subcutaneous tissue Vector Chrysops Tabanid (mango fly) Specimen Blood Microfilaria Sheathed Nuclei continuous up to the tip of the tail Periodicity Diurnal lec. Diagnosis 1. Intradermal test (Bachmann) 3. Bentonite flocculation (TS. difficulty in breathing and swallowing Adult: intestines -Abdominal pain. dead-end host Freezing destroys the larva Adult Male: w/ conical papillae Female: w/ club-shaped uterus (viviparous/larviparous) MOT Ingestion of meat Symptoms and pathology Larva: muscle -Edema. Xenodiagnostic tests (TS. muscle pain. peripheral nodules in the lung (coin lesions). Onchocerca volvulus Habitat Subcutaneous tissue Vector Simulium (black fly) Specimen Skin snips/shavings Microfilaria Unsheathed Nuclei absent in tail Periodicity Nonperiodic Dipetaloma perstans (Acanthoculonema perstans) Habitat Body cavities Vector Culicoides Specimen Blood Microfilaria Unsheathed Nuclei up to the tip of the tail Periodicity Nonperiodic Mansonella ozzardi Habitat Body cavities Vector Culicoides Specimen Blood Microfilaria Unsheathed Tail is free of nuclei Periodicity Nonperiodic Dirofilaria immitis Characteristics Human infection: solitary.mt 04 |Page | 120 . sashimi) lec. or as subcutaneous nodule Dracunculus medinensis Characteristics Longest nematode of man IH Cyclops (copepods): aquatic crustacean DH Man MOT Ingestion of crustacean Angiostrongylus cantonensis Characteristics Causes human eosinophilic meningoencephalitis IH Mollusks: -Achatina fulica -Japanese snail -Pila luzonica (kuhol) -Brotia asperata (suso) DH Rats Adult Female: “Barber’s pole appearance” Looking of whitish uterus to red digestrive tract Anisakis Characteristics Causes Herring’s disease 1st IH Various marine crustaceans 2nd IH Smallest fishes 3rd IH Larger fishes DH Dolphins/whales MOT Ingestion of raw fish (ex. plant/vegetation. gigantica F. buski -E. Egg: Non-operculated 4. IS: Cercaria (fork-tailed) 6. buski Adult w/ cephalic cone Leaf-like hermaphrodite lec. heterophyes Lungs: -P. ilocanum -H. sinensis Crab P. leaf like 1. heterophyes O. Egg: operculated 3. MOT: ingestion 4. IH: 1 IH (snail) Eggs: a. IH: 2 IH 6. Trematodes Phylum Platyhelminthes Class Trematoda (Flukes) Characteristics All except blood flukes [Schistosomes] Schistosomes: 1. IS: metacercaria 5. felineus C. ilocanum Habitat Liver: -F. gigantica and F.mt 04 |Page | 121 . snail Fish Schistosoma H. buski Snail E. felineus Small Intestines: -F. Separate sexes 3. crab. westermani Fasciola hepatica Characteristics Causes sheep liver rot Prevalent in sheep raising countries Egg Resembles F. hepatica F. Mature when laid (embryonated): “SHOC” -Schistosoma -Heterophyes -Opistorchis -Clonorchis b. MOT: skin penetration 5. gigantica -C. westermani Plant/vegetation F. Elongated and cylindrical 2. Immature when laid (unembryonated): “PEFF” -Paragonimus -Echinostoma -Fasciola -Fasciolopsis Attachment 2 suckers: oral and ventral (acetabulum) -Heterophyes: 3 suckers (3rd: genital sucker [gonotyle]) Life cycle Egg > Larva (Miracidium>Sporocyst>Redia>Cercaria>Metacercaria) > Adult 1st IH Snail 2nd IH Fish. Flat. sinensis -O. hepatica -F. Hermaphrodite 2. Diagnosis 1. sinensis Fasciolopsis buski Characteristics Largest fluke parasitizing man Egg Hen’s egg shaped Indistinguishable from Fasciola Echinostoma ilocanum 1st and 2nd IH Snail Heterophyes heterophyes Characteristics Smallest but deadliest fluke of man Adult w/ 3rd sucker (gonotyle) 1st IH Snail 2nd IH Fishes MOT Ingestion Paragonimus westermani Characteristics Causes endemic hemoptysis Egg w/ thickened abopercular end opposite the operculum Adult Resembles coffee bean 1st IH Snail 2nd IH Crabs MOT Ingestion Lab. Demonstration of egg in feces. and urine 2.mt 04 |Page | 122 . Fasciola gigantica Characteristics Infects cattle in the Philippines Egg Resembles F. Faust and Meleney’s egg hatching technique 3. Examination: sputum and stool Schistosomes Characteristics Most romantic parasite of man Adult Male: w/ gynecophoral canal where the female is held Lab. rectal or liver biopsies. buski Clonorchis sinensis Characteristics Most important liver fluke of man Egg Old-fashioned electric light bulb 1st IH Snail 2nd IH Fishes MOT Ingestion Opisthorcis felineus Characteristics Resembles C. Diagnosis 1. hepatica and F. Circumoval precipitin test (COP) of Oliver and Gonzales Pathology Larval penetration -Human sp: slight allergic reaction -Nonhuman sp: Swimmer’s itch Tissue damage by eggs Schistosoma japonicum Characteristics Causes Katayama’s disease Habitat Superior mesenteric veins in the small intestines Egg w/ small knob-like or recurved hook on one side IH Oncomelania quadrasi Schistosoma mansoni Characteristics Smallest of the blood flukes Habitat Superior mesenteric veins of the colon and rectum Egg w/ lateral spine IH Biomphalaria lec. saginata (IH: cattle) Require invertebrate IH D. embryonated (mature when laid). ripe/gravid (filled w/ eggs) Order Pseudophyllidea False tapeworm (Ex. striated. inside is an embryo Spherical. no rostellar hooks w/ rostellum armed w/ 2 rows of large and small hooklets Length 25 m 7m # of proglottids 1000-2000 <1000 Gravid proglottid 15-20 lateral branches 7-13 lateral branches (dichotomous or tree-like) (dendritic or fingerlike) Eggs Spherical.mt 04 |Page | 123 . immature when laid Stages: Coracidium > Procercoid > Plerocercoid IH: 2 IH (Copepods and fresh water fish) Order Cyclophyllidea True tapeworm Scolex: Quadrate. no hooklets Strobila: Anapolytic (not shedding segments) Egg: operculated w/ aboperculum. B12 deficiency anemia Uterus Rosette formation Lab. nana Diphyllobothrium latum Characteristics Largest tapeworm of man Causes Vit. Australorbis Tropicorbis Schistosoma haematobium Characteristics Vesical blood fluke causing bilharziasis or urinary schistosomiasis (hematuria) Egg w/ terminal spine IH Bulinus Physopsis Biomphalaria Specimen 24-hr unpreserved urine Trematodes Phylum Platyhelminthes Class Trematoda Characteristics Living worms: creamy white and yellowish Adult: flat and ribbon-like (masking tape) 1 IH only Cestode body Scolex = anterior attachment organ Neck = region of growth Strobila = chains of segments or proglottids -Immature. inside is an embryo w/ 6 hooklets w/ 6 hooklets Larva Cysticercus bovis Cysticercus cellulosae Pathogenesis Taeniasis saginata Taeniasis solium. D. mature. hexacanth embryo IH: 1 IH Require vertebrate IH T. Diagnosis 1. w/ 4 cuplike suckers (rostellum w/ or w/o hooklets) Strobila: Apolytic (shedding segments) Egg: non-operculated. striated. cysticercosis lec. caninum (MOT: ingestion of “pulgas”) May or may not require IH H. Stool examination = Egg: Diagnostic stage Taenia saginata Taenia solium Scolex None. solium (IH: pig) T. latum) Scolex: Spoon-shaped w/ bothria (slit-like sucking grooves). and some several nuclei Some contain vacuoles: for storage and transport Hemotogranules Special organs for locomotion -Sarcodina/Rhizopoda = Amoeba (pseudopods) -Mastigophora/Flagellata -Ciliophora/Ciliata -Sporozoa = no definite locomotory organelle Class Rhizopoda Trophozoites Motile Feeding stage Diarrheic/liquid stool Destroyed by iodine lec. Hymenolepis nana Hymenolepis diminuta Characteristics Smallest tapeworm of man Scolex w/ rostellum armed w/ a ring of 20. membrane w/ 2 polar thickenings. but from each w/c arise 4-8 polar w/o filaments filaments IS Direct: Eggs Cysticercoid larva Indirect: Cysticercoid larva DH Man Rat Dipylidium caninum Proglottids w/ double set of reproductive organs and genital pore on each side of the lateral margin Mature & gravid proglottids: melon seed/pumpkin seed/rice grain-shaped Eggs Egg packet (8-15 eggs) IH Ctenocephalides canis (dog flea) Ctenocephalides felis (cat flea) Pulex irritans (human flea) DH Dogs or cats Man: accidental host Echinococcus granulosus Characteristics Shortest tapeworm (only 3 segments: immature. ripe/gravid) Anti-P1 Eggs Resembles Taenia egg IH Sheep (IS: eggs) Man: accidental IH DH Dog Lab. EG) = Casoni (intradermal test) Protozoans Characteristics Unicellular Animal-like protists Division: Fission No cell wall w/ outer membrane (periplast) Cytoplasm: ectoplasm (outer) and endoplasm (inner) Contains at least 1. Diagnosis 1. Exploratory cyst puncture 2.mt 04 |Page | 124 . w/ an unarmed rostellum 30 spines Eggs w/ oncosphere enclosed in an inner w/ oncosphere enclosed in an inner membrane w/ 2 polar thickenings. Immunologic tests: = Bentonite flocculation test (TS. Roentgenogram (x-ray) 3. mature. sluggish -1 pseudopod (finger-like) -Many pseudopods (blunt & rounded) -Endoplasm: w/ RBC but no bacteria -Endoplasm: w/ bacteria.mt 04 |Page | 125 . centrally located -Karyosome: large. Acanthamoeba. histolytica but does not exhibit true progressive locomotion Opportunistic Amoeba Characteristics Free-living amoeba Inhabits the CNS Does not indicate fecal contamination Cause PAM (fatal) Includes: Naegleria. yeasts and or cell detritus (clean-looking) cell detritus (dirty-looking) -Nucleus: not visible when stained. Hartmanella lec. border of nuclear membrane -Karyosome: fine.Cyst Non-motile Nonfeeding stage Well-formed stool Infective stage Characteristics w/ cystic stage except Entamoeba gingivalis Inhabit the large intestine except Entamoeba gingivalis Commensals except Entamoeba histolytica Life cycle Trophozoite > Precystic > Cystic > Metacystic stage Entamoeba True amoeba Peripheral chromatin (trophozoite and cyst) Chromatoidal bars (cyst) Endolimax/Iodamoeba Other amoeba No peripheral chromatin No chromatoid bars Entamoeba histolytica Entamoeba coli Trophozoite -Motility: Unidirectional & progressive -Motility: several directions. eccentrically (Bull’s eye) located Cyst -Chromatoidal bars: coffin/rod/cigar/ -Chromatoidal bars: splinter-like/ sausage-shaped witch-broom/whisked broom -Mature cyst w/ 1-4 nuclei -Mature cyst w/ 1-8 nuclei Endolimax nana Smallest amoeba Size = RBC [Trophozoite] -Karyosome: large round dot [Cyst] -Usually oval -Nuclei: 4 (cross-eyed) Iodamoeba butschlii [Trophozoite] Iodamoeba williamsi -Karyosome: w/ cluster of achromatic granules [Cyst] -Large iodine-staining glycogen vacuole Entamoeba gingivalis Associated w/ gum infection [Trophozoite] Karyosome: small and centrally located Pseudopodia: similar to E. -Nucleus: when stained. consists of consists of thin nuclear membrane w/ thicker nuclear membrane w/ layer of layer of uniformly sized fine variously sized chromatin granules chromatin granules distributed along unevenly distributed along the inside inside the border of nuclear memb. jerky movement -3 anterior flagella and 1 w/in the cytostome [Cyst] -Lemon to oval-shaped -Protrusion at end -Nipple-like cyst Giardia lamblia/ Associated w/ Gay bowel syndrome Lamblia intestinalis [Trophozoite] -Pear-shaped -Bilaterally symmetrical -2 nuclei. w/ motile amoeba Acanthamoeba Causes keratitis (from contaminated contact lens care solution) Causes GAE Culture: BAP flooded w/ E. lying w/in the sucking disk -Falling leaf motility -Old man’s face/old man w/ eyeglasses [Cyst] -2-4 nuclei -Football-shaped Trichomonas Characteristics Trophozoite stage only Pear-shaped 4-5 flagella Jerky motility Undulating membrane: aids in locomotion lec. coli Class Mastigophora (Flagellata) Characteristics Possesses whip-like locomotory organelle called flagella Motor component: flagella and axonemes Neuromotor apparatus: kinetoplast w/c consists of blepharoplast and parabasal body (energizing portion) Digestive tract & Enteromonas hominis Genital flagellates Embadomonas intestinalis Chilomastix mesnili Giardia lamlia Trichomonas hominis Trichomonas tenax Trichomonas vaginalis Blood and Tissue flagellates Leishmania tropica Leishmania braziliensis Leishmania donovani Trypanosoma rhodesiense Trypanosoma gambiense Trypanosoma cruzi Embadomonas intestinalis [Trophozoite] -Cleftlike cytostome Chilomastix mesnili [Trophozoite] -Pear-shaped -Spiral groove curving across the body -Spiral boring.Naegleria fowleri Major causative agent of PAM Amoeboflagellate (trophozoite) Acquired while diving & swimming during hot weather in brackish/freshwater CSF: purulent.mt 04 |Page | 126 . each w/ a large karyosome. Diagnosis 1. lymph nodes. Feinberg-Whittington medium Hemoflagellates Characteristics Include the trypanosomes and leishmanias May infect the blood. muscles and RES Amastigote Leishman-Donovan body Leishmanial form Promastigote Leptomonal form Anterior to nucleus Epimastigote Crithidial form Near nucleus Trypomastigote Trypanosomal form Posterior to nucleus Leishmania tropica Agent of Old world cutaneous leishmaniasis Oriental sore Aleppo button Baghdad or Jericho boil Dry lesions Habitat Endothelial cells Monocytes lec. prostate & urethra Female: -Burning sensation -Strawberry cervix Lab. Costa: thickening of membrane Trichomonas tenax Habitat Oral cavity Size Smallest Nucleus Rounded Undulating membrane 2/3 of the costa Inclusion bodies None Specimen Oral scrapings Trichomonas hominis Habitat Intestine Size Medium Nucleus Ovoidal Undulating membrane As long as the costa Inclusion bodies None Specimen Stool Trichomonas vaginalis Habitat Genitalia Size Largest Nucleus Ovoidal Undulating membrane < ½ of the costa Inclusion bodies Siderophil granules Specimen Urine Vaginal swab/discharge (female) Prostatic secretion (male) Characteristics Causes Pingpong’s disease Male: carrier -Asymptomatic chronic urethritis -Epididymis.mt 04 |Page | 127 . Modified Diamond medium 2. Diagnosis 1. rhodesiense -West Africa: T. TC) Ciliates Balantidium coli The only significant ciliate Host: Pigs Largest parasitic protozoan lec. CNS Characteristics C-shaped Romaña’s sign Unilateral swelling of eye lids Lab. pharynx) Vector Phlebotomus Lutzomyia Pathology Wheeping lesions Lab. mouth.Vector Phlebotomus Lutzomyia Pathology Localized cutaneous infection (macule papule) Leishmania braziliensis Agent of American mucocutaneous leishmaniasis Espundia Bubas Habitat Mucocutaneous junctions (nasal septum. Sleeping sickness stage: CSF Trypanosoma cruzi Agent of American trypanosomiasis Chagas’ disease Vectors Triatomid bugs Kissing bugs Reduviid bugs Assasin bugs Cone nose bugs Triatoma rubrofasciata = Philippines Habitat RES. Dr. Xenodiagnostic test (TS. Diagnosis 1. Febrile stage: blood. cardiac muscle. Chang’s medium 2. lymph node Sleeping sickness: CSF Winterbottom sign Inflammation/swelling of lymph nodes Lab. Diagnosis 1. Culture: = NNN: Novy-McNeal-Nichole medium (culture for Leishmania & Trypanosoma) Trypanosoma rhodesiense & Trypanosoma gambiense Agent of African sleeping sickness -East Africa: T. gambiense Vector Glossina (tsetse fly) Habitat Febrile: blood. Diagnosis 1. Montenegro’s (skin test) Leishmania donovani Agent of Visceral leishmaniasis Kala-azar (black fever) Dum-dum fever Habitat Endothelial cells of RES Macrophages Vector Phlebotomus Lutzomyia Pathology Splenomegaly Severe anemia Lab.mt 04 |Page | 128 . lymph node aspirate 2. Examination of blood film a. releases merozoites Responsible for relapse (P. Thin blood film = Identification of species -Fix w/ methanol -Stain w/ Giemsa lec. malariae 2. Recurrent chills and fever -every 36 hours: malignant tertian malaria = P. joint pain 3. Diagnosis 1. ovale -every 48 hours: benign tertian malaria = P.mt 04 |Page | 129 . falciparum Lab. P. Merozoites (RBC) ---> Trophozoites ---> Schizont ---> Release merozoites 2. Merozoites ---> Destroyed by immune system Sexual Life cycle Macrogametocytes & Microgametocytes ---> Anopheles mosquito Anopheles ---> Macro. Merozoites ---> Microgametocytes (Male)/Macrogametocytes (Female) 3. vivax. MOT: ingestion of cysts (from swine feces) S/S: Dysentery [Trophozoite] -Macronucleus: kidney-shaped. reproductive -Cilia. Thick blood film = Screening purposes -Dehemoglobinize RBCs -Stain w/ Giemsa b. organisms and pigment block brain vessels -Blackwater fever: intravascular hemolysis + hemoglobinuria Resistant to malaria G-6-PD deficiency Fy (a-b-) Sickle cell disease Hypnozoites Dormant stage Found in the liver Once activated. vivax & P. ovale) Mixed infection P. splenomegaly. P. vivax -every 72 hours: quartan malaria = P. falciparum -every 48 hours: ovale malaria = P. vegetative -Micronucleus: dot-like. oral cytostome (mouth) [Cyst] -Refractive double wall enclosing cilia -Nonmotile Sporozoa Characteristics Obligate intracellular No apparent means of locomotion Life cycle Sexual (sporogony) = DH (arthropod vector) Asexual (schizogony) = IH (man) Plasmodium Characteristics Cause of malaria (“bad air”) IS IH (man): Sporozoites DH (mosquito): Gametocytes Asexual Life cycle Female Anopheles ---(sporozoites)---> Man ---> Liver (Exoerythrocytic cycle)---- --->Infected cells (liver) will rupture & release merozoites --> Erythrocytic cycle Erythrocytic cycle: 1.+ Microgametocytes = Zygote (ookinete) Ookinete ---> Oocysts (contains sporozoites) --->Matured: release sporozoites Sporozoites ---(Female Anopheles)---> Man Symptoms and Pathology 1. falciparum: fatal -Cerebral malaria: RBC. Anemia (RBC destruction). mt 04 |Page | 130 . falciparum rings -No malarial pigment -No growing trophozoite DH Deer MOT Ixodes tick bite Blood transfusion Symptoms and pathology Headache & fever Hemolytic anemia + hemoglobinuria lec. QBC: Quantitative buffy coat -Fluorochrome: Acridine orange 3. falciparum) Plasmodium vivax Characteristics Prevalent worldwide Single large ring succeeded by amoeboid form in pale large red cell Schuffner’s dots (condensed Hgb) Relapse: Hypnozoites Infects reticulocytes only Infected RBCs: enlarged # of Merozoites Usually 16 Trophozoite Amoeboid Gametocyte Round Plasmodium malariae Characteristics Single large compact ring or band forms Invades old RBCs Ziemann’s dots Schizont arranged around central pigment (rosette/daisy head/fruit pie arrangement) # of Merozoites 8 Trophozoite Band Gametocyte Ovoid Plasmodium falciparum Characteristics Prevalent in the Philippines Ring forms: small (1/6 diameter red cell). 2. Immunotests a. Malaquick test -Detects HRP-2 or HRP II Ag (P. Optimal assay -Detects pLDH (parasitic LDH) = malarial organism b. appliqué forms/marginal/accole formation/double chromatin dots Maurer’s dots (Stephen Christopher/Cuneiform dots) Multiple parasitization of red cells Infects all age of red cells # of Merozoites 24-32 Trophozoite Ring Gametocytes Crescent/sausage/banana-shaped Plasmodium ovale Characteristics Single compact ring Schuffner’s dots/James’ dots Relapse: Hypnozoites Infected RBCs: serrated/fimbriated # of Merozoites 8-9 Babesia microti Characteristics “Maltese-cross” formation Resembles P. pigs DH: man MOT: sporulated oocyst in contaminated food and water Diseases: -Asymptomatic -Diarrhea. hominis/S. Sheather sugar flotation 2. Diagnosis 1. parvum/C. parvum: bovines (C. frothy diarrhea among immunosuppressed patients -Acute and gangrenous cholecystitis Lab. suihominis) Diseases: -Gastroenteritis w/ diarrhea -Eosinophilic enteritis -Myalgia (mild increase in CK) Toxoplasma gondii Characteristics Common cause of congenital infection DH Cat -Oocyst in cat feces may infect man IH Man -Bradyzoite = inactive form -Tachyzoite = actively dividing Lab.mt 04 |Page | 131 . hominis: man Diseases: -Watery. Diagnosis: 1. vermicularis eggs lec. hominis) C. Stool examination 3. Modified acid fast stain (CIC) Cyclospora cayetanensis Originally called a cyanobacterium-like body (CLB) Causes chronic and intermittent watery diarrhea Sarchocystis Zoite: simplest form (banana-shaped) (S. Sabin-Feldman dye test -Methylene blue staining of tachyzoites is inhibited by prior addition of patient serum containing antibodies to Toxoplasma Other Intestinal Protozoans Blastocystis hominis Vacuolated form (most predominant): -A large central vacuole pushes the cytoplasm and nuclei to the periphery of the cell Dientamoeba fragilis Former amoeba Now classified as a flagellate Trophozoite stage only -2 nuclei (“Binucleated trophozoite”) MOT: via transmission of E. Babesia bigemia Characteristics Causes “red water fever” in cattles Coccidia Characteristics Schizogony (asexual) = nucleated cells Sporogony (sexual) = intestinal mucosa of DH Infective stage Oocyst (feces) Isospora belli IH: cattles. flatulence -Acalculous cholecystitis Cryptosporidium C. Fluorochrome acridine orange in microhematocrit centrifuge format -QBC blood parasite detection method Examination of Fecal Specimens Stool fixatives 1.: helminth eggs and larvae 2.: protozoan cysts = 10% conc. Formalin = all purpose fixative = 5% conc. Polyvinyl alcohol (PVA) = for Trichrome stain (w/ HgCl2) 4. Preparation of buffy coat smears: -L. donovani -Trypanosomes -Microfilaria 2. Thimerosal = Merthiolate and Iodine: staining components = Formalin: preservative lec.a.k. D.mt 04 |Page | 132 . each containing about 15 eggs Blatella germanica German cockroach Blatta orientalis Oriental cockroach Aedes aegypti Tiger mosquito Vector of urban dengue Aedes albopictus w/ silvery stripe on the mesonotum Vector of rural dengue Culex Vectors of Japanese encephalitis Anopheles flavirostris Primary vector of malaria Aedes poecilus Mosquito associated w/ Bancroftian filariasis Mansonia bonneae Vector of the Brugian type of filariasis Musca domestica Common housefly Sarcophaga “Chess-board appearance” Calliphora Bluish fly covered w/ yellow hairs Lucilia Greenish fly w/ white genae Phaenicia Bronze-bottle fly Muscina Slightly larger and more robust than the housefly Laboratory Methods Examination of Blood Detect agents of Malaria Babesiosis Trypanosomiasis Leishmaniasis Filariasis Thick blood films Screening (malaria) Thin blood films Identification of malarial species Concentration techniques 1. latum. Knott’s concentration membrane filtration -Detection of microfilaria 3. Schaudinn’s fluid = w/ HgCl2 3. Merthiolate-iodine-formalin (MIF) = a. Arthropods Copepods (Cyclops) IH of D. medinensis and Gnathostoma spinigerum Pthirus pubis Crab louse Agent of “crabs” Myiasis Invasion of mammalian tissues by dipterous larvae (diptera/flies) Cantharidin Volatile vessicating substance produced by the blisters of beetles of the family Meloidae Periplaneta americana American cockroach Lays about 50 egg capsules (ootheca). Isospora. Acid-ether concentration = Ether: dissolves fats and CHO 2. Kato Katz smear (Cellophane fecal thick smear) = quantitative Nematode culture and 1. Direct smear method of Beaver 2. Kato thick smear = qualitative (Cellophane paper.mt 04 |Page | 133 . Iron hematoxylin stain 3.85% NSS 2. philippinensis (sedimentation) = NOT for Schistosomal and operculated eggs (sedimentation) Cultural Methods for Protozoa Culture media for intestinal 1. Harada-Mori paper strip culture recovery techniques 2. 5. Muscle biopsy = Trichinella spiralis lec. Wheatley’s trichrome stain 2. Zinc Sulfate centrifugal flotation technique = SG (ZnSO4): 1. Boeck and Dorbohlav’s diphasic medium (Modified by Dobell and Laidlaw) amoeba 2. Saline mount = 0.18 = for Protozoan cysts = for Nematode eggs except T. Sodium-acetate-formalin (SAF) = Advantage: does not contain HgCl2 Direct wet mount 1. glycerine. Skin biopsy = Onchocerca. Iodine mount = protozoan cysts (not trophozoites) Permanent stains 1. Cyclospora) Concentration Methods for Protozoan Cysts and Helminth Eggs and Larva Sedimentation Best for eggs of: -Schistosoma -Operculated egg -Trematodes -Cestodes -T. Mansonella 2. trichiura and C. philippinensis 1. Stoll dilution egg count 3. Modified acid fast stains (Cryptosporidium. vaginalis Specimens: -Vaginal and urethral discharge -Prostatic secretions -Urine Sputum Recovery of protozoal and helminthic parasites Biopsy 1. malachite green) 4. Formalin-ether concentration = Formalin: preserves the eggs Flotation 1. trichiura -C. Cleveland Collier’s medium NNN Medium for Trypanosoma and Leishmania (Novy-McNeal-Nicolle) Additional Techniques for Examination of Enteric Parasites Cellulose tape technique For pinworms Egg studies 1. Baermann funnel techniques (Strongyloides) Examination of Other Specimens Detection of T. Brine Flotation = NaCl 2.