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Medical Parasitology Lab. Revision . 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: - PowerPoint PPT Presentation
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MEDICAL PARASITOLOGY LAB.
REVISION
R. Z. Ahmed, Medical Parasitology Lab., 2011
Parasites
Endoparasitic Helminthes
Platy helminthes
(Flat worm)
Trematoda(Flukes)
Cestoda(Tape worm)
Nematode(Round worm)
Protozoa
Protozoao 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
Nematode o 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
Trematodao Also name as Flukes.
o 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
Intestinal Protozoa1. Entamoeba histolytica/ dispar
o E. histolytica inhabit large intestine and cause amoebic
dysentery.
o There is two diagnostic stages for E. histolytica/ dispar:
1. Cyst ( infective stage ).
2. Trophozoite ( motile form, motility by pseudopodia ).
o Diagnosis:
Stool examination to see cyst stage, or trophozoite stage if
the sample is fresh.
R. Z. Ahmed, Medical Parasitology Lab.,
2011
E. histolytica/disparCyst
Iodine Wet mount
R. Z. Ahmed, Medical Parasitology Lab., 2011
E. histolytica/dispar
Trophozoite
R. Z. Ahmed, Medical Parasitology Lab., 2011
Intestinal Protozoa2. Giardia Lamblia
o It is the most common flagellate of the intestinal tract that
cause giardiasis .
o There is two diagnostic stages for Giardia lamblia :
1. Cyst ( infective stage ).
2. Trophozoite ( motile form, motility by flagella ).
o Diagnosis:
Stool examination to see cyst stage, or trophozoite stage if
the sample is fresh.
R. Z. Ahmed, Medical Parasitology Lab., 2011
G. lamblia Cyst
R. Z. Ahmed, Medical Parasitology Lab., 2011
G. lamblia Trophozoite
R. Z. Ahmed, Medical Parasitology Lab., 2011
Urogenital Protozoa3. Trichomonas vaginalis
o Its pathogenic, inhabit the urogenital system.
o There is no cyst stage but only have trophozoite stage:
o Trophozoite is the infective and diagnostic stage and motile by
flagella.
o 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
Intestinal Protozoa4. Cryptosporidium
parvumo Infect human and most mammals.
o There is one diagnostic stage for Cryptosporidium parvum:
Oocyst have 4 sporozoites.
o Infective stage: Oocyst containing sporozoites.
o Diagnosis: Detecting oocyst in stool. Staining with Acid – fast stain.
R. Z. Ahmed, Medical Parasitology Lab., 2011
C. parvum oocyst
R. Z. Ahmed, Medical Parasitology Lab., 2011
Tissue Protozoa5. Toxoplasma gnodii
o Habitat: reticulo-endothelial system, monocyte, and
muscle fiber and cause toxoplasmosis.
o There are two diagnostic stages for Toxoplasma gondii:
1. Cyst
2. Oocyst have 4 tachyzoites .
o Infective stage: Oocyst.
o Intermediate host: Human.
o Definitive host: Cat.
R. Z. Ahmed, Medical Parasitology Lab., 2011
T. gondii tachyzoites
R. Z. Ahmed, Medical Parasitology Lab., 2011
R. Z. Ahmed, Medical Parasitology Lab., 2011
Blood Parasites
Blood Parasite
Plasmodium
Plasmodium falciparum
Plasmodium vivax
Plasmodiumovale
Plasmodium malariae
Microfilariae
Trypanosoma
Leishmania
Blood Protozoa6. Trypanosoma spp.
o T. cruci (Americans) cause Chaga’s disease.
o T. bruci (Africans) cause sleeping sickness disease.
o have many stages: Amastigote, Promastigote, Trypomastigote, and Epimastigote.
o Intermediate host: Tse tse fly.
o Definitive host: Human.
o Infective stage: Metacyclic trypomastigote.
o Diagnostic stage: Trypomastigote.
o Diagnosis:Blood smear within 21 days from the bite, it will show the
parasites. R. Z. Ahmed, Medical Parasitology Lab., 2011
Trypanosoma
R. Z. Ahmed, Medical Parasitology Lab., 2011
Blood protozoao There is many species affect man:
L. tropica : cause skin lesion ( cutaneous ) L. braziliense : cause muco-cutaneous lesion. L. donovani : cause visceral lesion.
o 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. o Intermediate host: Sand fly.o Definitive host: Human.o Diagnosis:
- Thick and thin blood film.- Skin scraping.
7. Leishmania spp.
R. Z. Ahmed, Medical Parasitology Lab., 2011
Leishmania promastigote
R. Z. Ahmed, Medical Parasitology Lab., 2011
Blood Protozoao Four species of Plasmodium are the causative agent of
malaria, these are: P. vivax, P. malariae, P. falciparum, and P. ovale.
o Intermediate host: Human.
o Definitive host: Anopheles mosquitoes.
o Plasmodium spp. have 4 stages: Ring form (young trophozoite.), Late ( old ) trophozoite,
Schizonts, and Gametocyte.
o Infective stage: Sporozoites.
o Diagnosis: Thick and stained thin blood film to detect parasites.
8. Plasmodium spp.
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. vivax P. ovale
P. malariae P. falciparum
Trophozoite form
P. vivax P. ovale
P. malariae P. falciparum
Schizonts form
P. vivax P. ovale
P. malariae P. falciparum
Gametocyte form
P. vivax P. ovale
P. malariae P. falciparum
Comparison
R. Z. Ahmed, Medical Parasitology Lab., 2011
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
Good species differentiation
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
round
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 singleMature schizont rare, 12-30
merozoites12-24
merozoites4-12
merozoites( scattered )
6-12 merozoites
( rosette )Gametocyte crescent
shapelarge, round large, round compact,
round
Nematode1. Ascaris lumbricoides o Ascaris lumbricoides is the giant roundworm of human, inhabit
small intestine and cause Ascariasis .
o There are three diagnostic stages for Ascaris lumbricoides :
1. Eggs (embryonated, fertilized, and unfertilized).
2. Larvae.
3. Adult: Male: have 2 minute spicules and copulatory bursa. Female: pointed tail and have no spicules.
o Infective stage: Embryonated eggs.
o Diagnosis: Stool analysis to detect egg or larvae.
R. Z. Ahmed, Medical Parasitology Lab., 2011
Adult Stage
50 cm
30 cm
R. Z. Ahmed, Medical Parasitology Lab., 2011
Ova or eggso There are 3 shapes of ova:
1. Embryonated egg: Corticated. Decorticated.
2. Fertilized egg: Corticated. Decorticated.
3. Unfertilized egg: Corticated. Decorticated.
R. Z. Ahmed, Medical Parasitology Lab., 2011
Embryonated egg
Corticated DecorticatedR. Z. Ahmed, Medical Parasitology Lab.,
2011
Fertilized eggs
Corticated DecorticatedR. Z. Ahmed, Medical Parasitology Lab.,
2011
Unfertilized eggs
Corticated DecorticatedR. Z. Ahmed, Medical Parasitology Lab.,
2011
Larvae stage
R. Z. Ahmed, Medical Parasitology Lab., 2011
Nematodeo Other names: human pin worm and seat worm.
o Young and mature worms are present in small intestine (at
terminal ileum till fertilization).
o Gravid females are present at lower rectum where they lay ova at
perianal region around anus.
o Infective stage: Eggs.
o Diagnosis:
- Egg in stool is rarely detected but adults present after
purgative.
- Egg can be detected at perianal area by using scotch tape test.
2. Enterobius vermicularis
R. Z. Ahmed, Medical Parasitology Lab., 2011
E. vermicularis adult
R. Z. Ahmed, Medical Parasitology Lab., 2011
E. vermicularis eggs
R. Z. Ahmed, Medical Parasitology Lab., 2011
Nematodeo Inhabit human intestine ( jejunum, ileum, and rarely duodenum )
and cause Anclystomiasis.
o Male shorter than female and have copulatory bursa and two
spicules.
o Female is long and has pointed end.
o Both sexes have long buccal cavity with two pairs of teeth.
o Infective stage: Filariform larvae.
o Diagnosis:- Based on finding ova in fresh stool sample.- In old sample, larvae present and must be differentiated from
larvae of Strongyloides stercoralis .
3. Anclystoma duodenalae ( Hook worm )
R. Z. Ahmed, Medical Parasitology Lab., 2011
Anclystoma Eggo Hook worm eggs like insects or mites egg, therefore must be
differentiated.
Mites egg Hook worm egg
R. Z. Ahmed, Medical Parasitology Lab., 2011
Plant material
Anclystoma adult
MaleFemale
R. Z. Ahmed, Medical Parasitology Lab., 2011
Anclystoma larvae
R. Z. Ahmed, Medical Parasitology Lab., 2011
Filariform Rhabditiform
Anclystoma male copulatory bursa
R. Z. Ahmed, Medical Parasitology Lab., 2011
Anclystoma buccal capsule
R. Z. Ahmed, Medical Parasitology Lab., 2011
Nematode
o Adults lives in the small intestine ( duodenum and jejunum ).
o Male have a pointed curved tail associated with two spicules.
o Female have strait tail without spicules.
o In contrast to the Anclystoma spp., both sexes have short
buccal cavity.
o Infective stage: Filariform larvae.
o Diagnosis:- Based on recovery of the rhabditiform larvae passed in
stool.- If diarrhea is present, eggs may also be recovered.
4. Strongyloides stercoralis
R. Z. Ahmed, Medical Parasitology Lab., 2011
S. stercoralis larvae
R. Z. Ahmed, Medical Parasitology Lab., 2011
Rhabditiform
Filariform
S. stercoralis adult male
spicules
spicules
R. Z. Ahmed, Medical Parasitology Lab., 2011
S. stercoralis adult female
R. Z. Ahmed, Medical Parasitology Lab., 2011
Aspect Anclystoma spp. (Hook worm)
Strongyloides stercoralis
Rhabditiform larvae
Buccal cavity Long Short
Esophagus One – third of the body
One – third of the body
Genital permordium Absence Prominent
Filariform larvae
Esophagus One – third of the body
Half of the body
Tail Pointed Notched
larvae Striated sheath Unsheathed R. Z. Ahmed, Medical Parasitology Lab.,
2011
Comparison
Nematode o Adult inhabit the large intestine and cause trichuriasis.
o Adult male is smaller than female.
o Trichuris trichiura eggs have distinct shape.
o Because of the shape of this worm ( anterior thin and
posterior thick ) called whip worm.
o Infective stage: Eggs.
o Diagnosis:
Detection of eggs in the stool.
5. Trichuris trichiura ( whip worm )
R. Z. Ahmed, Medical Parasitology Lab., 2011
T. trichiura egg
R. Z. Ahmed, Medical Parasitology Lab., 2011
T. trichiura adult
R. Z. Ahmed, Medical Parasitology Lab., 2011
Nematodeo 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.
o Fertilized female only penetrate the mucosa where the
larviposit, they do not lay eggs.
o Larvae is the infective stage, live encysted in the flesh of the
host, and they represent the infective stage.
o Diagnosis: - By finding the adult parasites in early days of infection.- Finding larvae in the blood during migration or in muscle
after encystation.
6. Trichinella spiralis
R. Z. Ahmed, Medical Parasitology Lab., 2011
T. spiralis larvae encysted in muscle
R. Z. Ahmed, Medical Parasitology Lab., 2011
Cestoda1. Hymenolepis nana ( Dwarf tape worm )
o Larvae inhabit the small intestine so, there is no intermediate
host.
o This is the smallest tape worm in man.
o Eggs have double membrane and contain six hooked
oncosphere.
o Infective stage: Eggs.
o Diagnosis:
Stool examination to detect the eggs.
R. Z. Ahmed, Medical Parasitology Lab., 2011
H. nana adult
R. Z. Ahmed, Medical Parasitology Lab., 2011
H. nana eggs
R. Z. Ahmed, Medical Parasitology Lab., 2011
H. nana scolex
R. Z. Ahmed, Medical Parasitology Lab., 2011
Cestodao There are two species that infect man and cause Taeniasis.
Taenia saginata ( Beef tape worm ). Taenia solium ( Pork tape worm ).
o Both have mature, immature and gravid segments.
o Both have scolex provided with four cup- shaped suckers.
o In both species the infective stage is the cysticercus.
o Intermediate host: T. saginata: Cows. T. solium: Pigs.
o Definitive host: Human.
3. Taenia spp.
R. Z. Ahmed, Medical Parasitology Lab., 2011
Taenia spp.o Taenia saginata and Taenia solium must be differentiated from
each other by the following: Mature segment, gravid proglotid and adult worm.
o 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
R. Z. Ahmed, Medical Parasitology Lab., 2011
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
Eggs
R. Z. Ahmed, Medical Parasitology Lab., 2011
We can’t use egg to differentiate to species for each other
R. Z. Ahmed, Medical Parasitology Lab., 2011
Scolex
Taenia soliumTaenia saginata
R. Z. Ahmed, Medical Parasitology Lab., 2011
Mature segment
Taenia soliumTaenia saginata
Gravid proglotid
R. Z. Ahmed, Medical Parasitology Lab., 2011
Taenia soliumTaenia saginata
R. Z. Ahmed, Medical Parasitology Lab., 2011
Adult worm
Taenia soliumTaenia saginata
Trematodao Also name as Flukes.
o 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
Blood flukeso Eggs are non operculated, but spined.
o Cercaria has a bifid tail and penetrate intact skin.
o Cause human bilharziasis.
o There are three species: Schistosoma mansoni, cause intestinal bilharziasis. Schistosoma jabonicum, cause intestinal bilharziasis. Schistosoma haematobium, cause schistosomal hematuria
or urinary bilharziasis.
o Infective stage in three species is the Cercaria.
o Intermediate host: Snail.
o Definitive host: HumanR. Z. Ahmed, Medical Parasitology Lab.,
2011
Schistosoma spp.
Schistosoma spp.
R. Z. Ahmed, Medical Parasitology Lab., 2011
o 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.
o 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.
Snail
R. Z. Ahmed, Medical Parasitology Lab., 2011
Snails Schistosome species
Bulinus spp. S.haematobium
Biomphalaria spp. S.mansoni
Oncomelania spp. S.japonicum
Schistosoma egg
R. Z. Ahmed, Medical Parasitology Lab., 2011
S. jabonicumS. haematobiumS. mansoni
Lateral spine
Terminal spine Rounded spine
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
Snail
R. Z. Ahmed, Medical Parasitology Lab., 2011
Oncomelania spp.Biomphalaria spp.
Bulinus spp.
Liver flukes
R. Z. Ahmed, Medical Parasitology Lab., 2011
Fasciola spp. o Fasciola hepatica lives in the liver of man.
o Fasciola spp. have many stages: Oval eggs have miracidium, cercaria, metcercaria, larvae
and adult stage.
o Intermediate host: Snail.
o Definitive host: Sheep.
o Infective stage (human): Metacercaria.
o Human infected by ingestion metacercaria from infected
sheep.
o Diagnosis:
Stool analysis to find Fasciola egg.
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
F. hepatica larvae
R. Z. Ahmed, Medical Parasitology Lab., 2011
Medical entomologyo Lice
o Flea
o Bed bug
o Ticks Hard ticks Soft ticks
o Mite
R. Z. Ahmed, Medical Parasitology Lab., 2011
Lice
Lice egg
R. Z. Ahmed, Medical Parasitology Lab., 2011
Flea
R. Z. Ahmed, Medical Parasitology Lab., 2011
Ticks
R. Z. Ahmed, Medical Parasitology Lab., 2011
Ticks
Soft ticks Hard ticks
R. Z. Ahmed, Medical Parasitology Lab., 2011
Tick mouth part
R. Z. Ahmed, Medical Parasitology Lab., 2011
Mite
Mite egg
R. Z. Ahmed, Medical Parasitology Lab., 2011
Bed bug
R. Z. Ahmed, Medical Parasitology Lab., 2011
THE END