Symbiosis Commensalism Mutualism Parasitism Endoparasite Ectoparasite Erratic Obligate parasite Facultative parasite Accidental/incidental parasite Permanent parasite Temporary parasite Spurious parasite Definitive/final host Intermediate host Paratenic host Reservoir host Biologic vector Mechanical/phoretic vector Epidemiology Incidence Prevalence (%) Cumulative prevalence Intensity of infection (Worm burden) Morbidity Deworming Cure rate (%) Egg reduction rate Selective treatment Targeted treatment Universal treatment Coverage Efficacy Effectiveness
MUST TO KNOW IN PARASITOLOGY Living together of unlike organisms 2 species live together One species benefits from the relationship w/o harming or benefiting the other Ex. Entamoeba coli 2 organisms benefit from each other Ex. Termites and the flagellates inside their digestive system 1 organism lives in or on another for its survival at the expense of the host Ex. Entamoeba histolytica Lives inside the body of the host “Infection” Lives outside the body of the host “Infestation” Parasite found in an organ w/c is not its usual habitat Need a host to complete their development May exist in a free-living state May become parasitic when the need arises Parasite that established itself in a host where it does not ordinarily live Ex. Echinococcus granulosus Remains on or in the body of the host for its entire life Lives on the host only for a short period of time Free-living organism Passes through the digestive tract w/o infecting the host Parasite attains sexual maturity Harbors the asexual/larval stage of the parasite One in which the parasite does not develop further to later stages Parasite remains alive and is able to infect another host Allows the parasite’s life cycle to continue and become additional sources of infection Transmits the parasite only after the the latter has completed its development within the host Ex. Aedes mosquito Only transports the parasites Ex. Flies and cockroach Study of patterns, distribution and occurrence of disease Number of new cases of infection in a given period of time Number of individuals estimated to be infected w/ a particular parasite % of individuals in a population infected w/ at least 1 parasite Number of worms per infected person Clinical consequences of infections or diseases that affect an individual’s wellbeing Use of antihelminthic drugs in an individual Number of previously positive subjects found to be egg-negative % fall in egg counts after deworming Individual-level deworming Group-level deworming Population-level deworming Proportion of the target population reached by an intervention Effect of a drug against an infective agent Measure of the effect of a drug against an infective agent lec.mt 04 |Page | 112
Information-educationcommunication Environmental management Environmental sanitation Sanitation Eradication Elimination Protozoan Metazoan Sarcomastigophora Sarcodina
Mastigophora
Ciliophora Apicomplexa
Microspora
Nematoda Intestinal
Extraintestinal
A health education strategy that aims to encourage people to adapt and maintain healthy life practices Planning, organization, performance, and monitoring of activities for the modification and/or manipulation of environmental factors Interventions to reduce environmental health risks Provision of access to adequate facilities for the safe disposal of human excreta Permanent reduction to zero of the incidence of infection caused by a specific agent, as a result of deliberate efforts Reduction to zero of the incidence of a specified disease in a defined geographic area as a result of deliberate efforts Unicellular organism Multicellular organism Classification of Protozoan Parasites Acanthamoeba Endolimax Entamoeba Iodamoeba Naegleria Chilomastix Dientamoeba Giardia Trichomonas Leishmania Trypanosoma Balantidium Babesia Cryptosporidium Cyclospora Isospora Plasmodium Toxoplasma Enterocytozoon Encephalitozoon Vittaforma Trachipleistophora Pleistophora Brachiola Microsporidium Classification of Metazoan Parasites Ascaris Capillaria Enterobius Hookworm Strongyloides Trichuris Angiostrongylus Filarial worms Trichinella
lec.mt 04 |Page | 113
Cestoidea Cyclophyllidea
Pseudophyllidea Trematoda
Arthropoda Arachnida
Chilopoda Crustacea Diplopoda Insecta
Pentastomida Ascaris lumbricoides Enterobius vermicularis
Trichuris trichiura Capillaria philippinensis Necator americanus Ancylostoma duodenale Ancylostoma braziliense Ancylostoma caninum Strongyloides stercoralis
Dipylidium Echinococcus Hymenolepis Raillientina Taenia Diphyllobothrium Spirometra Artyfechinostomum Clonorchis Echinostoma Fasciola Fasciolopsis Heterophyids Opisthorchis Paragonimus Schistosoma Mites Scorpions Spiders Ticks Centipedes Copepods Crabs Millipedes Flies Flea Beetle Bees Lice Wasp Bugs Mosquitoes Tongue worms Common/Other Names Giant intestinal roundworm Lumbricus teres Pinworm Oxyuris vermicularis Seatworm Social or Society worm Whipworm Pudoc worm American hookworm American murderer New world hookworm Old world hookworm Cat hookworm Dog hookworm Threadworm lec.mt 04 |Page | 114
Trichinella spiralis Wuchereria bancrofti Brugia malayi Loa loa Onchocerca volvulus Dirofilaria immitis Dracunculus medinensis
Anisakis Toxocara canis Toxocara cati Fasciola hepatica Fasciola gigantica Clonorchis sinensis Fasciolopsis buski Echinostoma ilocanum Heterophyes heterophyes Paragonimus westermani Schistosoma japonicum Schistosoma mansoni Schistosoma haematobium Taenia saginata Taenia solium Hymenolepis nana Hymenolepis diminuta Dipylidium caninum Diphyllobothrium latum Echinococcus granulosus Cyst Trophozoite Sporozoites Trypomastigote Promastigote Embryonated egg
Larva Filariform larva 3rd stage larva (filiform)
Muscle worm Garbage worm Bancroft’s filarial worm Malayan filarial worm Eye worm Blinding worm Dog/canine heartworm Guinea worm Fiery serpent of the Israelites Medina worm Dragon worm Fish and Marine mammal roundworm Herring’s worm Dog ascarid Cat ascarid Sheep liver fluke Giant liver fluke Oriental liver fluke Chinese liver fluke Giant intestinal fluke Garrison’s fluke Von Siebold’s fluke Oriental lung fluke Oriental blood fluke Profile of a man Bladder fluke Beef tapeworm Pork tapeworm Dwarf tapeworm Rat tapeworm (Norway rats) Dog tapeworm Double-pored tapeworm Broadfish tapeworm Hydatid worm Infective Stages Protozoans (amoebas) T. vaginalis Plasmodium Trypanosoma Leishmania “HATE” H. nana A. lumbricoides T. trichiura E. vermicularis T. spiralis C. philippinensis Hookworm S. stercoralis W. bancrofti B. malayi lec.mt 04 |Page | 115
Cercaria Metacercaria
Cysticercus bovis Cysticercus cellulosae Plerocercoid larva Hydatid cyst Cysticercoid larva
Separate sexes Life cycle Aphasmids Phasmids
Amphid Oviparous Ovoviviparous/oviviparous Viviparous/larviparous Frequency Small intestines Large intestines Heart-to-lung migration Extraintestinal Nematodes Visceral Larva Migrans Triad of infection/Unholy 3 Characteristics Fertilized Egg
A. cantonensis L. loa O. volvulus Mansonella S. japonicum S. haematobium S. mansoni F. hepatica F. buski C. sinensis O. felineus P. westermani E. ilocanum Heterophyids T. saginata T. solium D. latum E. granulosus H. diminuta D. caninum Nematodes (Roundworms) Female = larger, pointed tail Male = smaller, curved tail Egg stage > Larval stage > Adult stage Lacks phasmids or caudal chemoreceptors “TCT”: Trichuris-Capillaria-Trichinella w/ caudal chemoreceptors Hookworm S. stercoralis W. bancrofti B. malayi Cephalic chemoreceptors Lays eggs in unsegmented stage (unembryonated) Lays eggs in segmented stage (embryonated) Larva “EAT”: Enterobius > Ascaris > Trichuris “CASH”: Capillaria, Ascaris, Strongyloides, Hookworms “ET”: Enterobius, Trichuris “ASH”: Ascaris, Strongyloides, Hookworm Filarial worms = lymphatics and subcutaneous tissues T. spiralis = muscles A. cantonensis = meninges T. canis and T. cati “HAT”: Hookworm, Ascaris, Trichuris Ascaris lumbricoides Resembles common earthworm 3 layers: -Inner: Vitelline membrane -Middle: Glycogen layer -Outer: Mammilation (corticated) lec.mt 04 |Page | 116
Unfertilized Egg
Adult MOT Symptoms and Pathology Lab. Diagnosis
Characteristics Egg Adult MOT Symptoms and Pathology
Lab. Diagnosis Characteristics Egg Adult MOT Symptoms and Pathology Lab. Diagnosis Characteristics Egg Adult MOT IH
Symptoms and Pathology
2 layers: -Inner: Glycogen -Outer: Mammilation Has lecithin granules Buccal cavity: Triangular, trilobate lips Ingestion Larval migration: Eosinophilia (resembles Loeffler’s syndrome) Adult: Erratic Extraintestinal sites Intestinal perforation 1. Stool exam = Egg: Diagnostic stage = If (-) stool exam: a. No infection b. Early infection c. All MALE WORM infection Enterobius vermicularis Autoinfection: Same host (EV, SS) External autoinfection Elongated, flattened on 1 side D-shaped w/ lateral wings or cephalic alae Ingestion Mother’s complex: -Pruritus ani -Lack of sleep -Extraintestinal enterobiasis 1. Perianal swab: Scotch tape swab = Egg: Diagnostic stage Trichuris trichiura Causes trichocephaliasis Barrel-shaped w/ bipolar mucus plug Resembles Japanese lantern Slender or attenuated in the anterior Resembles a whip Ingestion Rectal prolapse (Heavy infection) 1. Stool exam = Egg: Diagnostic stage Capillaria philippinensis Causes pudoc disease or mystery disease w/ bipolar mucus plugs that are not as protruded as T. trichiura egg Guitar, peanut-shaped Male: w/ chitinized spicule (spicule sheath) Female: have eggs in utero Ingestion of freshwater fishes Fresh water fishes: -Hypselotris bipartite (ipon) -Birot -Bagsang -Bagtu Malabsorption (CP, GL) Borborygmi = peculiar abdominal gurgling sound lec.mt 04 |Page | 117
Lab. Diagnosis Characteristics Egg Adult
Rhabditiform larva
Filariform larva
MOT Symptoms and Pathology
Lab. Diagnosis
Characteristics
Adult Rhabditiform larva Filariform larva MOT Symptoms and pathology
Characteristics
LBM alternating w/ constipation 1. Stool exam = Egg: Diagnostic stage Hookworms (Necator, Ancylostoma) Agent of laziness in poor white population and tropical anemia in Puerto Rico Same for all species Ovoidal, thin-shelled, colorless “Morula ball” N. americanus: S-shaped, w/ semilunar cutting plates A. duodenale: C-shaped, w/ 2 pairs of teeth Male copulatory bursa: -Bipartite (2 digits): Barbed & bristle like -Tripartite (3 digits): Simple & not barbed 1st stage larva Short and stout Open mouth: feeding stage Buccal cavity: long Genital primordium: small or inconspicuous 2nd stage larva Long and slender Closed mouth: nonfeeding stage Sheath: (+) Tail: Pointed Skin penetration Mazza Mora/Water sore or ground itch Severe itching/allergic reaction at the site of skin penetration IDA Cutaneous larva migrans (Creeping eruption): A. braziliense and A. caninum (animal hookworm) 1. Stool exam = Egg: Diagnostic stage 2. Harada Mori Culture technique = Filter paper culture technique = For hookworm and threadworm larvae 3. Baermann funnel technique (Strongyloides) Strongyloides stercoralis Causes Cochin-China diarrhea Facultative nematode: -Parasitic: small intestine -Free-living: soil Female: capable of parthenogenesis (fertilization w/o the benefit of male) Buccal cavity: short Genital primordium: prominent or conspicuous Sheath: (-) Tail: Notched Skin penetration Skin: Allergic reaction Larval migration: pneumonia Intestines: abdominal pain, diarrhea, vomiting Trichinella spiralis Adult: in intestines Larva: in muscles lec.mt 04 |Page | 118
Adult MOT Symptoms and pathology
Lab. Diagnosis
Characteristics
Adults Microfilaria Lab. Diagnosis
Habitat Vector Specimen Microfilaria Periodicity Habitat Vector Specimen Microfilaria Periodicity Habitat Vector Specimen Microfilaria Periodicity
Requires 2 host to complete its life cycle Propagated by black and brown rats Man: both DH and IH, dead-end host Freezing destroys the larva Male: w/ conical papillae Female: w/ club-shaped uterus (viviparous/larviparous) Ingestion of meat Larva: muscle -Edema, muscle pain, difficulty in breathing and swallowing Adult: intestines -Abdominal pain, diarrhea 1. Muscle biopsy = Encysted larva: Diagnostic stage 2. Immuno-tests: a. Bentonite flocculation (TS, EG) b. Intradermal test (Bachmann) 3. Xenodiagnostic tests (TS, TC) = Beck’s albino rats/mice Filarial Worms Vector-borne nematodes DH: man (IS: filiform larva/3rd stage larva) IH: vector (IS: microfilaria) DS: Microfilaria In lymphatics and subcutaneous tissue In blood 1. Knott’s technique = Isolation of microfilaria = Blood + formalin + Giemsa stain Wuchereria bancrofti Lymphatics Aedes Anopheles Blood Sheathed Nuclei absent in tail Nocturnal (10PM-2AM) Brugia malayi Lymphatics Mansonia Blood Sheathed Tail w/ 2 separate nuclei Subperiodic Nocturnal Loa loa Subcutaneous tissue Chrysops Tabanid (mango fly) Blood Sheathed Nuclei continuous up to the tip of the tail Diurnal lec.mt 04 |Page | 119
Habitat Vector Specimen Microfilaria Periodicity Habitat Vector Specimen Microfilaria Periodicity Habitat Vector Specimen Microfilaria Periodicity Characteristics Characteristics IH DH MOT Characteristics IH
DH Adult Characteristics 1st IH 2nd IH 3rd IH DH MOT
Onchocerca volvulus Subcutaneous tissue Simulium (black fly) Skin snips/shavings Unsheathed Nuclei absent in tail Nonperiodic Dipetaloma perstans (Acanthoculonema perstans) Body cavities Culicoides Blood Unsheathed Nuclei up to the tip of the tail Nonperiodic Mansonella ozzardi Body cavities Culicoides Blood Unsheathed Tail is free of nuclei Nonperiodic Dirofilaria immitis Human infection: solitary, peripheral nodules in the lung (coin lesions), or as subcutaneous nodule Dracunculus medinensis Longest nematode of man Cyclops (copepods): aquatic crustacean Man Ingestion of crustacean Angiostrongylus cantonensis Causes human eosinophilic meningoencephalitis Mollusks: -Achatina fulica -Japanese snail -Pila luzonica (kuhol) -Brotia asperata (suso) Rats Female: “Barber’s pole appearance” Looking of whitish uterus to red digestrive tract Anisakis Causes Herring’s disease Various marine crustaceans Smallest fishes Larger fishes Dolphins/whales Ingestion of raw fish (ex. sashimi)
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Trematodes Phylum Class Characteristics
Attachment Life cycle 1st IH 2nd IH Fish
Crab Plant/vegetation Snail Habitat
Characteristics Egg Adult
Platyhelminthes Trematoda (Flukes) All except blood flukes [Schistosomes] Schistosomes: 1. Flat, leaf like 1. Elongated and cylindrical 2. Hermaphrodite 2. Separate sexes 3. Egg: operculated 3. Egg: Non-operculated 4. MOT: ingestion 4. MOT: skin penetration 5. IS: metacercaria 5. IS: Cercaria (fork-tailed) 6. IH: 2 IH 6. IH: 1 IH (snail) Eggs: a. Mature when laid (embryonated): “SHOC” -Schistosoma -Heterophyes -Opistorchis -Clonorchis b. Immature when laid (unembryonated): “PEFF” -Paragonimus -Echinostoma -Fasciola -Fasciolopsis 2 suckers: oral and ventral (acetabulum) -Heterophyes: 3 suckers (3rd: genital sucker [gonotyle]) Egg > Larva (Miracidium>Sporocyst>Redia>Cercaria>Metacercaria) > Adult Snail Fish, crab, plant/vegetation, snail Schistosoma H. heterophyes O. felineus C. sinensis P. westermani F. hepatica F. gigantica F. buski E. ilocanum Liver: -F. hepatica -F. gigantica -C. sinensis -O. felineus Small Intestines: -F. buski -E. ilocanum -H. heterophyes Lungs: -P. westermani Fasciola hepatica Causes sheep liver rot Prevalent in sheep raising countries Resembles F. gigantica and F. buski w/ cephalic cone Leaf-like hermaphrodite lec.mt 04 |Page | 121
Characteristics Egg Characteristics Egg 1st IH 2nd IH MOT Characteristics Characteristics Egg 1st and 2nd IH Characteristics Adult 1st IH 2nd IH MOT Characteristics Egg Adult 1st IH 2nd IH MOT Lab. Diagnosis Characteristics Adult Lab. Diagnosis Pathology
Characteristics Habitat Egg IH Characteristics Habitat Egg IH
Fasciola gigantica Infects cattle in the Philippines Resembles F. hepatica and F. buski Clonorchis sinensis Most important liver fluke of man Old-fashioned electric light bulb Snail Fishes Ingestion Opisthorcis felineus Resembles C. sinensis Fasciolopsis buski Largest fluke parasitizing man Hen’s egg shaped Indistinguishable from Fasciola Echinostoma ilocanum Snail Heterophyes heterophyes Smallest but deadliest fluke of man w/ 3rd sucker (gonotyle) Snail Fishes Ingestion Paragonimus westermani Causes endemic hemoptysis w/ thickened abopercular end opposite the operculum Resembles coffee bean Snail Crabs Ingestion 1. Examination: sputum and stool Schistosomes Most romantic parasite of man Male: w/ gynecophoral canal where the female is held 1. Demonstration of egg in feces, rectal or liver biopsies, and urine 2. Faust and Meleney’s egg hatching technique 3. Circumoval precipitin test (COP) of Oliver and Gonzales Larval penetration -Human sp: slight allergic reaction -Nonhuman sp: Swimmer’s itch Tissue damage by eggs Schistosoma japonicum Causes Katayama’s disease Superior mesenteric veins in the small intestines w/ small knob-like or recurved hook on one side Oncomelania quadrasi Schistosoma mansoni Smallest of the blood flukes Superior mesenteric veins of the colon and rectum w/ lateral spine Biomphalaria lec.mt 04 |Page | 122
Characteristics Egg IH Specimen Phylum Class Characteristics Cestode body
Order Pseudophyllidea
Order Cyclophyllidea
Require vertebrate IH Require invertebrate IH May or may not require IH Characteristics Uterus Lab. Diagnosis Scolex Length # of proglottids Gravid proglottid Eggs Larva Pathogenesis
Australorbis Tropicorbis Schistosoma haematobium Vesical blood fluke causing bilharziasis or urinary schistosomiasis (hematuria) w/ terminal spine Bulinus Physopsis Biomphalaria 24-hr unpreserved urine Trematodes Platyhelminthes Trematoda Living worms: creamy white and yellowish Adult: flat and ribbon-like (masking tape) 1 IH only Scolex = anterior attachment organ Neck = region of growth Strobila = chains of segments or proglottids -Immature, mature, ripe/gravid (filled w/ eggs) False tapeworm (Ex. D. latum) Scolex: Spoon-shaped w/ bothria (slit-like sucking grooves), no hooklets Strobila: Anapolytic (not shedding segments) Egg: operculated w/ aboperculum, immature when laid Stages: Coracidium > Procercoid > Plerocercoid IH: 2 IH (Copepods and fresh water fish) True tapeworm Scolex: Quadrate, w/ 4 cuplike suckers (rostellum w/ or w/o hooklets) Strobila: Apolytic (shedding segments) Egg: non-operculated, embryonated (mature when laid), hexacanth embryo IH: 1 IH T. solium (IH: pig) T. saginata (IH: cattle) D. caninum (MOT: ingestion of “pulgas”) H. nana Diphyllobothrium latum Largest tapeworm of man Causes Vit. B12 deficiency anemia Rosette formation 1. Stool examination = Egg: Diagnostic stage Taenia saginata Taenia solium None, no rostellar hooks w/ rostellum armed w/ 2 rows of large and small hooklets 25 m 7m 1000-2000 <1000 15-20 lateral branches 7-13 lateral branches (dichotomous or tree-like) (dendritic or fingerlike) Spherical, striated, inside is an embryo Spherical, striated, inside is an embryo w/ 6 hooklets w/ 6 hooklets Cysticercus bovis Cysticercus cellulosae Taeniasis saginata Taeniasis solium, cysticercosis lec.mt 04 |Page | 123
Characteristics Scolex Eggs
IS DH Proglottids Eggs IH DH Characteristics Eggs IH DH Lab. Diagnosis
Hymenolepis nana Hymenolepis diminuta Smallest tapeworm of man w/ rostellum armed w/ a ring of 20w/ an unarmed rostellum 30 spines w/ oncosphere enclosed in an inner w/ oncosphere enclosed in an inner membrane w/ 2 polar thickenings, membrane w/ 2 polar thickenings, but from each w/c arise 4-8 polar w/o filaments filaments Direct: Eggs Cysticercoid larva Indirect: Cysticercoid larva Man Rat Dipylidium caninum 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 Egg packet (8-15 eggs) Ctenocephalides canis (dog flea) Ctenocephalides felis (cat flea) Pulex irritans (human flea) Dogs or cats Man: accidental host Echinococcus granulosus Shortest tapeworm (only 3 segments: immature, mature, ripe/gravid) Anti-P1 Resembles Taenia egg Sheep (IS: eggs) Man: accidental IH Dog 1. Exploratory cyst puncture 2. Roentgenogram (x-ray) 3. Immunologic tests: = Bentonite flocculation test (TS, EG) = Casoni (intradermal test) Protozoans
Characteristics
Hemotogranules
Trophozoites
Unicellular Animal-like protists Division: Fission No cell wall w/ outer membrane (periplast) Cytoplasm: ectoplasm (outer) and endoplasm (inner) Contains at least 1, and some several nuclei Some contain vacuoles: for storage and transport Special organs for locomotion -Sarcodina/Rhizopoda = Amoeba (pseudopods) -Mastigophora/Flagellata -Ciliophora/Ciliata -Sporozoa = no definite locomotory organelle Class Rhizopoda Motile Feeding stage Diarrheic/liquid stool Destroyed by iodine lec.mt 04 |Page | 124
Cyst
Characteristics Life cycle Entamoeba Endolimax/Iodamoeba
Trophozoite
Cyst Endolimax nana
Iodamoeba butschlii Iodamoeba williamsi Entamoeba gingivalis
Characteristics
Non-motile Nonfeeding stage Well-formed stool Infective stage w/ cystic stage except Entamoeba gingivalis Inhabit the large intestine except Entamoeba gingivalis Commensals except Entamoeba histolytica Trophozoite > Precystic > Cystic > Metacystic stage True amoeba Peripheral chromatin (trophozoite and cyst) Chromatoidal bars (cyst) Other amoeba No peripheral chromatin No chromatoid bars Entamoeba histolytica Entamoeba coli -Motility: Unidirectional & progressive -Motility: several directions, sluggish -1 pseudopod (finger-like) -Many pseudopods (blunt & rounded) -Endoplasm: w/ RBC but no bacteria -Endoplasm: w/ bacteria, yeasts and or cell detritus (clean-looking) cell detritus (dirty-looking) -Nucleus: not visible when stained; -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. border of nuclear membrane -Karyosome: fine, centrally located -Karyosome: large, eccentrically (Bull’s eye) located -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 Smallest amoeba Size = RBC [Trophozoite] -Karyosome: large round dot [Cyst] -Usually oval -Nuclei: 4 (cross-eyed) [Trophozoite] -Karyosome: w/ cluster of achromatic granules [Cyst] -Large iodine-staining glycogen vacuole Associated w/ gum infection [Trophozoite] Karyosome: small and centrally located Pseudopodia: similar to E. histolytica but does not exhibit true progressive locomotion Opportunistic Amoeba Free-living amoeba Inhabits the CNS Does not indicate fecal contamination Cause PAM (fatal) Includes: Naegleria, Acanthamoeba, Hartmanella lec.mt 04 |Page | 125
Naegleria fowleri
Major causative agent of PAM Amoeboflagellate (trophozoite) Acquired while diving & swimming during hot weather in brackish/freshwater CSF: purulent, w/ motile amoeba Acanthamoeba Causes keratitis (from contaminated contact lens care solution) Causes GAE Culture: BAP flooded w/ E. 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, 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, each w/ a large karyosome, 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.mt 04 |Page | 126
Habitat Size Nucleus Undulating membrane Inclusion bodies Specimen Habitat Size Nucleus Undulating membrane Inclusion bodies Specimen Habitat Size Nucleus Undulating membrane Inclusion bodies Specimen Characteristics
Lab. Diagnosis Characteristics Amastigote Promastigote Epimastigote Trypomastigote Agent of
Habitat
Costa: thickening of membrane Trichomonas tenax Oral cavity Smallest Rounded 2/3 of the costa None Oral scrapings Trichomonas hominis Intestine Medium Ovoidal As long as the costa None Stool Trichomonas vaginalis Genitalia Largest Ovoidal < ½ of the costa Siderophil granules Urine Vaginal swab/discharge (female) Prostatic secretion (male) Causes Pingpong’s disease Male: carrier -Asymptomatic chronic urethritis -Epididymis, prostate & urethra Female: -Burning sensation -Strawberry cervix 1. Modified Diamond medium 2. Feinberg-Whittington medium Hemoflagellates Include the trypanosomes and leishmanias May infect the blood, lymph nodes, muscles and RES Leishman-Donovan body Leishmanial form Leptomonal form Anterior to nucleus Crithidial form Near nucleus Trypanosomal form Posterior to nucleus Leishmania tropica Old world cutaneous leishmaniasis Oriental sore Aleppo button Baghdad or Jericho boil Dry lesions Endothelial cells Monocytes lec.mt 04 |Page | 127
Vector Pathology Agent of Habitat Vector Pathology Lab. Diagnosis Agent of Habitat Vector Pathology Lab. Diagnosis Agent of Vector Habitat Winterbottom sign Lab. Diagnosis Agent of Vectors
Habitat Characteristics Romaña’s sign Lab. Diagnosis Balantidium coli
Phlebotomus Lutzomyia Localized cutaneous infection (macule papule) Leishmania braziliensis American mucocutaneous leishmaniasis Espundia Bubas Mucocutaneous junctions (nasal septum, mouth, pharynx) Phlebotomus Lutzomyia Wheeping lesions 1. Dr. Montenegro’s (skin test) Leishmania donovani Visceral leishmaniasis Kala-azar (black fever) Dum-dum fever Endothelial cells of RES Macrophages Phlebotomus Lutzomyia Splenomegaly Severe anemia 1. Culture: = NNN: Novy-McNeal-Nichole medium (culture for Leishmania & Trypanosoma) Trypanosoma rhodesiense & Trypanosoma gambiense African sleeping sickness -East Africa: T. rhodesiense -West Africa: T. gambiense Glossina (tsetse fly) Febrile: blood, lymph node Sleeping sickness: CSF Inflammation/swelling of lymph nodes 1. Febrile stage: blood, lymph node aspirate 2. Sleeping sickness stage: CSF Trypanosoma cruzi American trypanosomiasis Chagas’ disease Triatomid bugs Kissing bugs Reduviid bugs Assasin bugs Cone nose bugs Triatoma rubrofasciata = Philippines RES, cardiac muscle, CNS C-shaped Unilateral swelling of eye lids 1. Chang’s medium 2. Xenodiagnostic test (TS, TC) Ciliates The only significant ciliate Host: Pigs Largest parasitic protozoan lec.mt 04 |Page | 128
Characteristics Life cycle Characteristics IS Asexual Life cycle
Sexual Life cycle
Symptoms and Pathology
Resistant to malaria Hypnozoites
Mixed infection Lab. Diagnosis
MOT: ingestion of cysts (from swine feces) S/S: Dysentery [Trophozoite] -Macronucleus: kidney-shaped, vegetative -Micronucleus: dot-like, reproductive -Cilia, oral cytostome (mouth) [Cyst] -Refractive double wall enclosing cilia -Nonmotile Sporozoa Obligate intracellular No apparent means of locomotion Sexual (sporogony) = DH (arthropod vector) Asexual (schizogony) = IH (man) Plasmodium Cause of malaria (“bad air”) IH (man): Sporozoites DH (mosquito): Gametocytes Female Anopheles ---(sporozoites)---> Man ---> Liver (Exoerythrocytic cycle)------>Infected cells (liver) will rupture & release merozoites --> Erythrocytic cycle Erythrocytic cycle: 1. Merozoites (RBC) ---> Trophozoites ---> Schizont ---> Release merozoites 2. Merozoites ---> Microgametocytes (Male)/Macrogametocytes (Female) 3. Merozoites ---> Destroyed by immune system Macrogametocytes & Microgametocytes ---> Anopheles mosquito Anopheles ---> Macro- + Microgametocytes = Zygote (ookinete) Ookinete ---> Oocysts (contains sporozoites) --->Matured: release sporozoites Sporozoites ---(Female Anopheles)---> Man 1. Recurrent chills and fever -every 36 hours: malignant tertian malaria = P. falciparum -every 48 hours: ovale malaria = P. ovale -every 48 hours: benign tertian malaria = P. vivax -every 72 hours: quartan malaria = P. malariae 2. Anemia (RBC destruction), splenomegaly, joint pain 3. P. falciparum: fatal -Cerebral malaria: RBC, organisms and pigment block brain vessels -Blackwater fever: intravascular hemolysis + hemoglobinuria G-6-PD deficiency Fy (a-b-) Sickle cell disease Dormant stage Found in the liver Once activated, releases merozoites Responsible for relapse (P. vivax, P. ovale) P. vivax & P. falciparum 1. Examination of blood film a. Thick blood film = Screening purposes -Dehemoglobinize RBCs -Stain w/ Giemsa b. Thin blood film = Identification of species -Fix w/ methanol -Stain w/ Giemsa lec.mt 04 |Page | 129
Characteristics
# of Merozoites Trophozoite Gametocyte Characteristics
# of Merozoites Trophozoite Gametocyte Characteristics
# of Merozoites Trophozoite Gametocytes Characteristics
# of Merozoites Characteristics
DH MOT Symptoms and pathology
2. QBC: Quantitative buffy coat -Fluorochrome: Acridine orange 3. Immunotests a. Optimal assay -Detects pLDH (parasitic LDH) = malarial organism b. Malaquick test -Detects HRP-2 or HRP II Ag (P. falciparum) Plasmodium vivax 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 Usually 16 Amoeboid Round Plasmodium malariae Single large compact ring or band forms Invades old RBCs Ziemann’s dots Schizont arranged around central pigment (rosette/daisy head/fruit pie arrangement) 8 Band Ovoid Plasmodium falciparum Prevalent in the Philippines Ring forms: small (1/6 diameter red cell), 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 24-32 Ring Crescent/sausage/banana-shaped Plasmodium ovale Single compact ring Schuffner’s dots/James’ dots Relapse: Hypnozoites Infected RBCs: serrated/fimbriated 8-9 Babesia microti “Maltese-cross” formation Resembles P. falciparum rings -No malarial pigment -No growing trophozoite Deer Ixodes tick bite Blood transfusion Headache & fever Hemolytic anemia + hemoglobinuria lec.mt 04 |Page | 130
Characteristics Characteristics Infective stage Isospora belli
Cryptosporidium (C. parvum/C. hominis)
Cyclospora cayetanensis Sarchocystis (S. hominis/S. suihominis)
Characteristics DH IH Lab. Diagnosis
Blastocystis hominis Dientamoeba fragilis
Babesia bigemia Causes “red water fever” in cattles Coccidia Schizogony (asexual) = nucleated cells Sporogony (sexual) = intestinal mucosa of DH Oocyst (feces) IH: cattles, pigs DH: man MOT: sporulated oocyst in contaminated food and water Diseases: -Asymptomatic -Diarrhea, flatulence -Acalculous cholecystitis C. parvum: bovines C. hominis: man Diseases: -Watery, frothy diarrhea among immunosuppressed patients -Acute and gangrenous cholecystitis Lab. Diagnosis: 1. Sheather sugar flotation 2. Stool examination 3. Modified acid fast stain (CIC) Originally called a cyanobacterium-like body (CLB) Causes chronic and intermittent watery diarrhea Zoite: simplest form (banana-shaped) Diseases: -Gastroenteritis w/ diarrhea -Eosinophilic enteritis -Myalgia (mild increase in CK) Toxoplasma gondii Common cause of congenital infection Cat -Oocyst in cat feces may infect man Man -Bradyzoite = inactive form -Tachyzoite = actively dividing 1. Sabin-Feldman dye test -Methylene blue staining of tachyzoites is inhibited by prior addition of patient serum containing antibodies to Toxoplasma Other Intestinal Protozoans Vacuolated form (most predominant): -A large central vacuole pushes the cytoplasm and nuclei to the periphery of the cell Former amoeba Now classified as a flagellate Trophozoite stage only -2 nuclei (“Binucleated trophozoite”) MOT: via transmission of E. vermicularis eggs
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Copepods (Cyclops) Pthirus pubis Myiasis Cantharidin Periplaneta americana Blatella germanica Blatta orientalis Aedes aegypti Aedes albopictus Culex Anopheles flavirostris Aedes poecilus Mansonia bonneae Musca domestica Sarcophaga Calliphora Lucilia Phaenicia Muscina
Arthropods IH of D. latum, D. medinensis and Gnathostoma spinigerum Crab louse Agent of “crabs” Invasion of mammalian tissues by dipterous larvae (diptera/flies) Volatile vessicating substance produced by the blisters of beetles of the family Meloidae American cockroach Lays about 50 egg capsules (ootheca), each containing about 15 eggs German cockroach Oriental cockroach Tiger mosquito Vector of urban dengue w/ silvery stripe on the mesonotum Vector of rural dengue Vectors of Japanese encephalitis Primary vector of malaria Mosquito associated w/ Bancroftian filariasis Vector of the Brugian type of filariasis Common housefly “Chess-board appearance” Bluish fly covered w/ yellow hairs Greenish fly w/ white genae Bronze-bottle fly 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. Preparation of buffy coat smears: -L. donovani -Trypanosomes -Microfilaria 2. Knott’s concentration membrane filtration -Detection of microfilaria 3. Fluorochrome acridine orange in microhematocrit centrifuge format -QBC blood parasite detection method Examination of Fecal Specimens Stool fixatives 1. Formalin = all purpose fixative = 5% conc.: protozoan cysts = 10% conc.: helminth eggs and larvae 2. Schaudinn’s fluid = w/ HgCl2 3. Polyvinyl alcohol (PVA) = for Trichrome stain (w/ HgCl2) 4. Merthiolate-iodine-formalin (MIF) = a.k.a. Thimerosal = Merthiolate and Iodine: staining components = Formalin: preservative lec.mt 04 |Page | 132
Direct wet mount
5. Sodium-acetate-formalin (SAF) = Advantage: does not contain HgCl2 1. Saline mount = 0.85% NSS 2. Iodine mount = protozoan cysts (not trophozoites)
Permanent stains
1. Wheatley’s trichrome stain 2. Iron hematoxylin stain 3. Modified acid fast stains (Cryptosporidium, Isospora, Cyclospora) Concentration Methods for Protozoan Cysts and Helminth Eggs and Larva Sedimentation Best for eggs of: -Schistosoma -Operculated egg -Trematodes -Cestodes -T. trichiura -C. philippinensis 1. Acid-ether concentration = Ether: dissolves fats and CHO 2. Formalin-ether concentration = Formalin: preserves the eggs Flotation 1. Brine Flotation = NaCl 2. Zinc Sulfate centrifugal flotation technique = SG (ZnSO4): 1.18 = for Protozoan cysts = for Nematode eggs except T. trichiura and C. philippinensis (sedimentation) = NOT for Schistosomal and operculated eggs (sedimentation) Cultural Methods for Protozoa Culture media for intestinal 1. Boeck and Dorbohlav’s diphasic medium (Modified by Dobell and Laidlaw) amoeba 2. 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. Direct smear method of Beaver 2. Stoll dilution egg count 3. Kato thick smear = qualitative (Cellophane paper, glycerine, malachite green) 4. Kato Katz smear (Cellophane fecal thick smear) = quantitative Nematode culture and 1. Harada-Mori paper strip culture recovery techniques 2. Baermann funnel techniques (Strongyloides) Examination of Other Specimens Detection of T. vaginalis Specimens: -Vaginal and urethral discharge -Prostatic secretions -Urine Sputum Recovery of protozoal and helminthic parasites Biopsy 1. Skin biopsy = Onchocerca, Mansonella 2. Muscle biopsy = Trichinella spiralis
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