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Medical Parasitology Lab. Staining of Parasites. Intestinal Protozoa. Cryptosporidium parvum. Raed Z. Ahmed, Medical Parasitology Lab.,2012. Cryptosporidium parvum. Infect human and most mammals. The infective stage is oocyst containing sporozoites measuring 4-6µ in diameter. - PowerPoint PPT PresentationTRANSCRIPT
Staining of Parasites
Medical Parasitology Lab.
Cryptosporidium parvum
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Intestinal Protozoa
Cryptosporidium parvum
Infect human and most mammals. The infective stage is oocyst containing sporozoites
measuring 4-6µ in diameter. The diagnostics stage is sporulated oocyst containing 4
sporozoites. Diagnosis:– Detecting oocyst in stool.– Acid-fast stain.
Raed Z. Ahmed, Medical Parasitology Lab.,2012
• The most common method of diagnosing Cryptosporidiosis is acid-fast staining methods or the Ziehl-Neelsen stain.
Cryptosporidium parvum oocyst
Cryptosporidium parvum oocyst
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Intestinal Protozoa
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Isospora belli
Isospora belli• Isosporiasis is a human intestinal disease caused by the parasite
Isospora belli.• The coccidian parasite Isospora belli infects the epithelial cells of
the small intestine, and is the least common of the three intestinal coccidia that infect humans.
• Infection causes acute, non-bloody diarrhea with crampy abdominal pain, which can last for weeks and result in malabsorption and weight loss. In immunodepressed patients, and in infants and children, the diarrhea can be severe. Eosinophilia may be present (differently from other protozoan infections).
• Diagnosis:– Acid- fast stain
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Isospora belli oocyst
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Tissue Nematodes
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Trichinella spiralis
Trichinella spiralis
Trichinella spiralis • Cause trichinosis, trichiniasis or trichinelliasis..• 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.
• Human infected by eating undercooked pork containing infective encysted larvae.
• Human is dead end host.
Raed Z. Ahmed, Medical Parasitology Lab.,2012
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• Diagnosis:– By finding the adult parasites in early days of infection.– Finding larvae in the blood during migration or in
muscle after encystation.– Immunological tests.– X- ray to detect the calcified larvae in muscle.
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Trichinella spiralis larvae encysted in muscle
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Intestinal Nematodes
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Entrobius vermicularis
Entrobius vermicularis
Entrobius vermicularis• Also named as human pin worm and seat worm, cause
oxyurdiasis.• 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 (oviparous).• The female is 0.88-1.3 cm long, it has a long tapering tail
resembling 1/3 its length, its strait.• The male is shorter than female (2-5 mm) the tail is curved
strongly to ventral side, and has a single spicule.• Infective stage: Embryonated Eggs.• Definitive host: human.
Raed Z. Ahmed, Medical Parasitology Lab.,2012
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• Diagnosis:– Egg in stool is rarely detected but adults present after
purgative.– Egg can be detected at perianal area as follow:• N.I.H method (National Institute of Health), its based on
swabbing the perianal area with a cellophane paper.• The adhesive cellulose tape (scotch tape), better result.• The Vaseline cloth wiping, the collected ova examined.
• Egg morphology:– 20-50u, transparent with double walled shell, it may show
one side convex and the other flat.
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Entrobius vermicularis Eggs
Entrobius vermicularis Adult
Raed Z. Ahmed, Medical Parasitology Lab.,2012
malefemale
Intestinal Nematodes
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Trichuris trichiura
Trichuris trichiura
Trichuris trichiura • Its commonly called whip worm because of the shape of
this worm (anterior thin and posterior thick).• Adult inhabit the large intestine in the caecum of man.• The adult male smaller than female, male 3.4-4.5 cm,
female 4-5 cm.• Trichuris trichiura eggs have distinct shape. (oviparous)• Diagnosis:– Stool examination to detect eggs.
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Trichuris trichiura Eggs
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Trichuris trichiura Adult
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Intestinal Nematodes
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Strongyloides stercoralis
Intestinal Nematodes
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Strongyloides stercoralis
Strongyloides stercoralis • Adults lives in the small intestine (duodenum and jejunum),
fertilized females are deeply embedded in the mucosa, where they also oviposit.
• Male have a pointed curved tail associated with two spicules.• Female have straight 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.
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Strongyloides stercoralis Larvae
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Rhabditiform
Filariform
S. Stercoralis Adult Male
Raed Z. Ahmed, Medical Parasitology Lab.,2012
spicules
spicules
S. Stercoralis Adult Female
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Intestinal Nematodes
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Ancylostoma duodenale
Intestinal Nematodes
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Anclystoma duodenale
Ancylostoma duodenalae (Hookworm)
• 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.
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Hookworm Eggs
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Hook worm eggs like insects or mites egg, therefore must be differentiated
Mites egg Hook worm eggPlant material
Hookworm Larvae
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Filariform Rhabditiform
Hookworm Adult
Raed Z. Ahmed, Medical Parasitology Lab.,2012
MaleFemale
Ancylostoma duodenalae copulatry burasa
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Ancylostoma duodenalae buccal capsule
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Comparison between Ancylostoma duodenalae and Necator americanus
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Ancylostoma duodenalae Necator americanus
Old world hookworm New world hookworm
Larger (male 8-11mm) Smaller (male 7-9mm)
Anterior end bent in same direction of general curvature of body
Anterior end bent in opposite direction of general curvature of body
Prominent buccal capsule with 2 pairs of teeth
Smaller buccal capsule with 2 pairs of semilunar cutting plates
Copulatory spicules not fused Copulatory spicules fused at ends to form a barbed tip
Copulatory bursa vs Copulatory Spicules
Raed Z. Ahmed, Medical Parasitology Lab.,2012
Necator americanus copulatory spiculesAncylostoma duodenalae copulatory spicules
Comparison between S. stercoralis and Hookworm
Raed Z. Ahmed, Medical Parasitology Lab.,2012
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