Medical Parasitology Lab. Revision

Endoparasitic Helminthes Parasites Endoparasitic Helminthes Platy helminthes (Flat worm) Trematoda (Flukes) Cestoda (Tape worm) Nematode (Round worm) Protozoa R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Protozoa Classification of protozoa according to final habitat in man: Intestinal and urogenital parasites: E.g.: Entamoeba histolytica, Giardia lambilia, Trichomonas vaginalis, Balantidium coli. Blood and Tissue parasites: E.g.: Toxoplasma gondii, Tryponasma spp., leishmania spp., Plasmodium spp.. R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Nematode Classification of nematode according to the final habitat in the man: Intestinal nematode: E.g.: Ascaris lumbricoides, Enterobius vermicularis, Anclystoma duodenalae, Trichuris trichiura, and Strongyloides stercoralis. Tissue nematode: E.g.: Wucheraria bancrofti, Trichinella spiralis, and Loa loa. R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Trematoda Also name as Flukes. Classification of Trematoda according to the final habitat in man: Liver flukes ( liver or bile ducts ): E.g.: Fasciola spp. Intestinal flukes : E.g.: Hetrophyes hetrophes. Blood flukes: E.g.: Schistosoma spp. R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Intestinal Protozoa Entamoeba histolytica/ dispar E. histolytica inhabit large intestine and cause amoebic dysentery. There is two diagnostic stages for E. histolytica/ dispar: Cyst ( infective stage ). Trophozoite ( motile form, motility by pseudopodia ). Diagnosis: Stool examination to see cyst stage, or trophozoite stage if the sample is fresh. R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 E. histolytica/dispar Cyst Iodine Wet mount R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 E. histolytica/dispar Trophozoite R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Intestinal Protozoa Giardia Lamblia It is the most common flagellate of the intestinal tract that cause giardiasis . There is two diagnostic stages for Giardia lamblia : Cyst ( infective stage ). Trophozoite ( motile form, motility by flagella ). Diagnosis: Stool examination to see cyst stage, or trophozoite stage if the sample is fresh. R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 G. lamblia Cyst R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 G. lamblia Trophozoite R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Urogenital Protozoa Trichomonas vaginalis Its pathogenic, inhabit the urogenital system. There is no cyst stage but only have trophozoite stage: Trophozoite is the infective and diagnostic stage and motile by flagella. Diagnosis: - Female: finding trophozoite in vaginal discharge. - Male: finding organism in urethral prostatic discharge. R. Z. Ahmed, Medical Parasitology Lab., 2011

T. Vaginalis trophozoite R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Intestinal Protozoa Cryptosporidium parvum Infect human and most mammals. There is one diagnostic stage for Cryptosporidium parvum: Oocyst have 4 sporozoites. Infective stage: Oocyst containing sporozoites. Diagnosis: Detecting oocyst in stool. Staining with Acid – fast stain. R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 C. parvum oocyst R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Tissue Protozoa Toxoplasma gnodii Habitat: reticulo-endothelial system, monocyte, and muscle fiber and cause toxoplasmosis. There are two diagnostic stages for Toxoplasma gondii: Cyst Oocyst have 4 tachyzoites . Infective stage: Oocyst. Intermediate host: Human. Definitive host: Cat. R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 T. gondii tachyzoites R. Z. Ahmed, Medical Parasitology Lab., 2011

Plasmodium falciparum Blood Parasites Blood Parasite Plasmodium Plasmodium falciparum Plasmodium vivax ovale Plasmodium malariae Microfilariae Trypanosoma Leishmania R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Blood Protozoa Trypanosoma spp. T. cruci (Americans) cause Chaga’s disease. T. bruci (Africans) cause sleeping sickness disease. have many stages: Amastigote, Promastigote, Trypomastigote, and Epimastigote. Intermediate host: Tse tse fly. Definitive host: Human. Infective stage: Metacyclic trypomastigote. Diagnostic stage: Trypomastigote. Diagnosis: Blood smear within 21 days from the bite, it will show the parasites. R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Trypanosoma R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Blood protozoa Leishmania spp. There is many species affect man: L. tropica : cause skin lesion ( cutaneous ) L. braziliense : cause muco-cutaneous lesion. L. donovani : cause visceral lesion. Have two stages: Amastigote ( Leishmania stage ), in man (reticuloendothelial cell). Promastigote ( Leptomonas stage ), the infective stage and present in the lumen gut of the sand fly. Intermediate host: Sand fly. Definitive host: Human. Diagnosis: - Thick and thin blood film. - Skin scraping. R. Z. Ahmed, Medical Parasitology Lab., 2011

Leishmania promastigote R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Blood Protozoa Plasmodium spp. Four species of Plasmodium are the causative agent of malaria, these are: P. vivax, P. malariae, P. falciparum, and P. ovale. Intermediate host: Human. Definitive host: Anopheles mosquitoes. Plasmodium spp. have 4 stages: Ring form (young trophozoite.), Late ( old ) trophozoite, Schizonts, and Gametocyte. Infective stage: Sporozoites. Diagnosis: Thick and stained thin blood film to detect parasites. R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011

Ring form P. ovale P. vivax P. malariae P. falciparum

Trophozoite form P. ovale P. vivax P. malariae P. falciparum

Schizonts form P. ovale P. vivax P. malariae P. falciparum

Gametocyte form P. ovale P. vivax P. malariae P. falciparum

R. Z. Ahmed, Medical Parasitology Lab., 2011 Comparison Thick smear Thin smear Lysed RBCs, many layer Fixed RBCs, single layer 0.25 μl blood/100 fields ( large volume ) 0.005 μl blood/100 fields ( small volume ) Good screening test ( positive or negative ) Good species differentiation Save time Requires more time to read Low density infection can be detected as blood elements more concentrate ( more sensitive ) Low density infections can be missed More difficult to diagnose species R. Z. Ahmed, Medical Parasitology Lab., 2011

Species differentiation on thin films   Species differentiation on thin films Feature P. falciparum P. vivax P. ovale P. malariae Enlarged infected RBC + Infected RBC shape round round, distorted oval, fimbriated Stippling infected RBC Mauer clefts Schuffner's spots Schuffner's dots none Trophozoite shape small ring, applique large ring, amoeboid large ring, compact small ring, compact Chromatin dot often double single large Mature schizont rare, 12-30 merozoites 12-24 merozoites 4-12 merozoites ( scattered ) 6-12 merozoites ( rosette ) Gametocyte crescent shape large, round compact, round

R. Z. Ahmed, Medical Parasitology Lab., 2011 Nematode Ascaris lumbricoides Ascaris lumbricoides is the giant roundworm of human, inhabit small intestine and cause Ascariasis . There are three diagnostic stages for Ascaris lumbricoides : Eggs (embryonated, fertilized, and unfertilized). Larvae. Adult: Male: have 2 minute spicules and copulatory bursa. Female: pointed tail and have no spicules. Infective stage: Embryonated eggs. Diagnosis: Stool analysis to detect egg or larvae. R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Adult Stage 50 cm 30 cm R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Ova or eggs There are 3 shapes of ova: Embryonated egg: Corticated. Decorticated. Fertilized egg: Unfertilized egg: R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Embryonated egg Corticated Decorticated R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Fertilized eggs Corticated Decorticated R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Unfertilized eggs Corticated Decorticated R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Larvae stage R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Nematode Enterobius vermicularis Other names: human pin worm and seat worm. Young and mature worms are present in small intestine (at terminal ileum till fertilization). Gravid females are present at lower rectum where they lay ova at perianal region around anus. Infective stage: Eggs. Diagnosis: - Egg in stool is rarely detected but adults present after purgative. - Egg can be detected at perianal area by using scotch tape test. R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 E. vermicularis adult R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 E. vermicularis eggs R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Nematode Anclystoma duodenalae ( Hook worm ) Inhabit human intestine ( jejunum, ileum, and rarely duodenum ) and cause Anclystomiasis. Male shorter than female and have copulatory bursa and two spicules. Female is long and has pointed end. Both sexes have long buccal cavity with two pairs of teeth. Infective stage: Filariform larvae. Diagnosis: Based on finding ova in fresh stool sample. In old sample, larvae present and must be differentiated from larvae of Strongyloides stercoralis . R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Anclystoma Egg Hook worm eggs like insects or mites egg, therefore must be differentiated. Mites egg Plant material Hook worm egg R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Anclystoma adult Female Male R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Anclystoma larvae Filariform Rhabditiform R. Z. Ahmed, Medical Parasitology Lab., 2011

Anclystoma male copulatory bursa R. Z. Ahmed, Medical Parasitology Lab., 2011

Anclystoma buccal capsule R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Nematode Strongyloides stercoralis Adults lives in the small intestine ( duodenum and jejunum ). Male have a pointed curved tail associated with two spicules. Female have strait tail without spicules. In contrast to the Anclystoma spp., both sexes have short buccal cavity. Infective stage: Filariform larvae. Diagnosis: Based on recovery of the rhabditiform larvae passed in stool. If diarrhea is present, eggs may also be recovered. R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 S. stercoralis larvae Rhabditiform Filariform R. Z. Ahmed, Medical Parasitology Lab., 2011

S. stercoralis adult male spicules spicules R. Z. Ahmed, Medical Parasitology Lab., 2011

S. stercoralis adult female R. Z. Ahmed, Medical Parasitology Lab., 2011

Anclystoma spp. (Hook worm) Strongyloides stercoralis Comparison Aspect Anclystoma spp. (Hook worm) Strongyloides stercoralis Rhabditiform larvae Buccal cavity Long Short Esophagus One – third of the body Genital permordium Absence Prominent Filariform larvae Half of the body Tail Pointed Notched larvae Striated sheath Unsheathed R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Nematode Trichuris trichiura ( whip worm ) Adult inhabit the large intestine and cause trichuriasis. Adult male is smaller than female. Trichuris trichiura eggs have distinct shape. Because of the shape of this worm ( anterior thin and posterior thick ) called whip worm. Infective stage: Eggs. Diagnosis: Detection of eggs in the stool. R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 T. trichiura egg R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 T. trichiura adult R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Nematode Trichinella spiralis Adult inhabit the small intestine of the rats and pigs. Both males and females lie freely in the lumen of the intestine of pigs and rats. Fertilized female only penetrate the mucosa where the larviposit, they do not lay eggs. Larvae is the infective stage, live encysted in the flesh of the host, and they represent the infective stage. Diagnosis: By finding the adult parasites in early days of infection. Finding larvae in the blood during migration or in muscle after encystation. R. Z. Ahmed, Medical Parasitology Lab., 2011

T. spiralis larvae encysted in muscle R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Cestoda Hymenolepis nana ( Dwarf tape worm ) Larvae inhabit the small intestine so, there is no intermediate host. This is the smallest tape worm in man. Eggs have double membrane and contain six hooked oncosphere. Infective stage: Eggs. Diagnosis: Stool examination to detect the eggs. R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 H. nana adult R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 H. nana eggs R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 H. nana scolex R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Cestoda Taenia spp. There are two species that infect man and cause Taeniasis. Taenia saginata ( Beef tape worm ). Taenia solium ( Pork tape worm ). Both have mature, immature and gravid segments. Both have scolex provided with four cup- shaped suckers. In both species the infective stage is the cysticercus. Intermediate host: T. saginata: Cows. T. solium: Pigs. Definitive host: Human. R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Taenia spp. Taenia saginata and Taenia solium must be differentiated from each other by the following: Mature segment, gravid proglotid and adult worm. Diagnosis: By finding gravid proglotid or eggs in stool. Direct fecal smear. Brine flotation technique. Cellophane - tape technique. R. Z. Ahmed, Medical Parasitology Lab., 2011

Comparison Taenia saginata Taenia solium Adult size Aspect Taenia saginata Taenia solium Adult size Longer ( 4 – 8 meters ) Smaller ( 2 - 4 meters ) Number of segment 1000 – 2000 700 - 1000 Mature segment Pass singly by their own activity Pass in chain Gravid proglotid With 15 – 30 uterine branches With 7 – 13 uterine branches Scolex Devoid rostellum and hooks With rostellum and 2 rows of hooks Larvae Cysticercus bovis in cattle only Cysticercus cellulosae in pig as well as in man R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Eggs We can’t use egg to differentiate to species for each other R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Scolex Taenia saginata Taenia solium R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Mature segment Taenia saginata Taenia solium R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Gravid proglotid Taenia saginata Taenia solium R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Adult worm Taenia saginata Taenia solium R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Trematoda Also name as Flukes. Classification of Trematoda according to the final habitat in man: Liver flukes ( liver or bile ducts ): E.g.: Fasciola hepatica. Intestinal flukes : E.g.: Hetrophyes hetrophes. Blood flukes: E.g.: Schistosoma spp. R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Blood flukes Schistosoma spp. Eggs are non operculated, but spined. Cercaria has a bifid tail and penetrate intact skin. Cause human bilharziasis. There are three species: Schistosoma mansoni, cause intestinal bilharziasis. Schistosoma jabonicum, cause intestinal bilharziasis. Schistosoma haematobium, cause schistosomal hematuria or urinary bilharziasis. Infective stage in three species is the Cercaria. Intermediate host: Snail. Definitive host: Human R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Schistosoma spp. Habitat: S. mansoni lives in the mesenteric venules of large intestine and produce eggs in stool. S. jabonicum lives in the mesenteric venules of small intestine and produce eggs in stool. S. haematobium lives in the venous plexus of the urinary bladder and produce eggs in urine. Diagnosis: Stool analysis should be performed to find eggs when infection with S. mansoni or S. jabonicum is suspected. Urine analysis should be performed to find eggs when infection with S. haematobium is suspected. R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Snail Snails Schistosome species Bulinus spp. S.haematobium Biomphalaria spp. S.mansoni Oncomelania spp. S.japonicum R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Schistosoma egg S. mansoni S. haematobium S. jabonicum Lateral spine Terminal spine Rounded spine R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Schistosoma Cercaria R. Z. Ahmed, Medical Parasitology Lab., 2011

Schistosoma adult male R. Z. Ahmed, Medical Parasitology Lab., 2011

Schistosoma adult female R. Z. Ahmed, Medical Parasitology Lab., 2011

Schistosomal miracidium R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Snail Biomphalaria spp. Oncomelania spp. Bulinus spp. R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Liver flukes Fasciola spp. Fasciola hepatica lives in the liver of man. Fasciola spp. have many stages: Oval eggs have miracidium, cercaria, metcercaria, larvae and adult stage. Intermediate host: Snail. Definitive host: Sheep. Infective stage (human): Metacercaria. Human infected by ingestion metacercaria from infected sheep. Diagnosis: Stool analysis to find Fasciola egg. R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 F. hepatica egg R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 F. hepatica miracidium R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 F. hepatica larvae R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Medical entomology Lice Flea Bed bug Ticks Hard ticks Soft ticks Mite R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Lice Lice egg R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Flea R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Ticks R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Ticks Soft ticks Hard ticks R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Tick mouth part R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Mite Mite egg R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 Bed bug R. Z. Ahmed, Medical Parasitology Lab., 2011

R. Z. Ahmed, Medical Parasitology Lab., 2011 THE END R. Z. Ahmed, Medical Parasitology Lab., 2011