Prepared By Mr Raed Z Ahmed Medical Parasitology
Prepared By: Mr. Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Intestinal Protozoa Cryptosporidium parvum Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
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 -2013
Cryptosporidium parvum oocyst • The most common method of diagnosing Cryptosporidiosis is acid-fast staining methods or the Ziehl-Neelsen stain. Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Intestinal Protozoa Isospora belli Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
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. • Diagnosis: – Acid- fast stain Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Isospora belli oocyst Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Tissue Nematodes Trichinella spiralis Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Life cycle Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Trichinella spiralis • Cause trichinosis, trichiniasis or trichinelliasis. . • Adult inhabit the small intestine of the rats, pigs and human. Both males and females lie freely in the lumen of the intestine of pigs, rats and human. • 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 diagnostic stage. • Human infected by eating undercooked pork containing infective encysted larvae. • Human is dead end host. Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Continue………. . • Diagnosis: – 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 -2013
Trichinella spiralis larvae encysted in muscle Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Intestinal Nematodes Entrobius vermicularis Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Life cycle Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
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 -2013
Continue……… • 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 -50 u, transparent with double walled shell, it may show one side convex and the other flat. Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Entrobius vermicularis Eggs Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Entrobius vermicularis Adult female Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Intestinal Nematodes Trichuris trichiura Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Life cycle Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
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 -2013
Trichuris trichiura Eggs Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Trichuris trichiura Adult Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Intestinal Nematodes Strongyloides stercoralis Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Life cycle Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
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 -2013
Strongyloides stercoralis Larvae Rhabditiform Filariform Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
S. Stercoralis Adult Male spicules Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
S. Stercoralis Adult Female Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Intestinal Nematodes Ancylostoma duodenale Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Life cycle Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
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 -2013
Hookworm Eggs Hook worm eggs like insects or mites egg, therefore must be differentiated Mites egg Plant material Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013 Hook worm egg
Hookworm Larvae Filariform Rhabditiform Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Hookworm Adult Female Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013 Male
Ancylostoma duodenalae copulatry burasa Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Ancylostoma duodenalae buccal capsule Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Comparison between Ancylostoma duodenalae and Necator americanus Ancylostoma duodenalae Old world hookworm Larger (male 8 -11 mm) Prominent buccal capsule with 2 pairs of teeth Copulatory spicules not fused Necator americanus New world hookworm Smaller (male 7 -9 mm) Smaller buccal capsule with 2 pairs of semilunar cutting plates Copulatory spicules fused at ends to form a barbed tip Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Copulatory bursa vs Copulatory Spicules Ancylostoma duodenalae copulatory spicules Necator americanus copulatory spicules Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
Comparison between S. stercoralis and Hookworm Aspect Anclystoma spp. (Hook worm) Strongyloides stercoralis Rhabditiform larvae Buccal cavity Esophagus Genital permordium Long Short One – third of the body Absence Prominent Filariform larvae Esophagus Tail larvae One – third of the body Half of the body Pointed Notched Striated sheath Unsheathed Raed Z. Ahmed, Medical Parasitology Lab. , 2012 -2013
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