1. Intestinal Nematodes

2. Classification of Parasites
helminths
Protozoa
Mulicellular
Specialized cells
Unicellular
Single cell for all function
Round worms
(Nematodes) cylindrical,
unsegmented
Flat worms
1-Trematodes:
leaf-like, unsegmented.
2-Cestodes:
tape-like, segmented
Amoebae:
move by psudobodia.
Flagellates:
move by flagella.
Ciliates :
move by cilia
Apicomplexa
(sporozoa) Tissue
parasites

3. Nematodes : General features
Elongated worm, cylindrical, unsegmented and tapering at both ends.
Variable in size, measure <1 cm to about 100cm.
Sex separate and male is smaller than female

4. Nematodes: Location in the human body
Intestinal nematodes
Tissue nematodes

5. Nematodes: common intestinal infections
Common intestinal nematode infections:
Enterobius (Oxyuris) vermicularis (Pinworm,seatworm,threadworm)
Trichuris trichiura (whipworm)
Ascaris lumbricoides (roundworm)
Ancylostoma duodenale & Necator americanus (hookworms)
Strongyloides stercoralis :

6. Enterobius vermicularis (Oxyuris)
(Common names :Pin worm, seat worm, thread worm(
Found all over the world.
adult in lumen of cecum and appendix from which adult female migrate to rectum.
It can be seen by naked eye as white thread ± 1cm.
Male is smaller than female ± 0.5cm, with coiled end.

7. Enterobius vermicularis (Oxyuris)
LIFE CYCLE

8. Pathology Enterobius vermicularis (Oxyuris)
Majority of infections are asymptomatic.
Main clinical presentation pruritus ani
perianal excoriation
Ectopic enterobiasis occurs in female when invade vulva and vagina result in valvovagintis
Usually accompanied by insomnia, anorexia, loss of weight and concentration (Side effect)

9. Enterobius vermicularis (Oxyuris)

10. Enterobius vermicularis (Oxyuris)

11. Treatment ِِAlbandazole , Mebendazole for whole family
Enterobius vermicularis (Oxyuris)
Treatment
ِِAlbandazole , Mebendazole
for whole family

12. Ascaris lumbricoides (roundworm)

13. Ascaris lumbricoides (roundworm)
Ascaris adult

14. Ascaris lumbricoides (roundworm)
The commonest human helminthes infection.
Found in jejunum and upper part of ileum.
Female ± 20 cm longer than male ± 10 cm
Feed on semi digested food.

15. Ascaris lumbricoides (roundworm)
LIFE CYCLE

16. Ascaris lumbricoides (roundworm)
Ascaris egg
(embryonated)

17. Ascaris eggs
Ascaris larva emerging from egg
Ascaris egg
(embryonated)

18. Ascaris lumbricoides (roundworm)
Pathology:
1-Adult worm:
Light infection : asymptomatic.
Heavy infection : intestinal obstruction
Migrating adult : to bile duct -jaundice
2-Larvae: Loeffler`s syndrome (imp)
Pneumonia, cough with bloody sputum
Eosinophilia, urticaria

19. Ascaris lumbricoides (roundworm)
Loeffler`s syndrome: Larvae in lung
pnumonia,cough ,bloody sputum

20. Ascaris lumbricoides (roundworm)
Ascaris larva in lung

21. Ascaris lumbricoides (roundworm)
Diagnosis:
-eggs in stool.
-larvae in sputum.
-adult may pass with stool.
Treatment: Albendazole , Mebendazole

22. Trichuris trichiura (Whipworm)

23. Trichuris trichiura (Whipworm)
LIFE CYCLE

24. Trichuris trichiura (whipworm)
World wide ,common in poor sanitation.
It coexists with Ascaris because of similar requirement.
Adult live in large intestine especially caecum and appendix –in heavy infection the whole length of large intestine affected.
Male and female worm have narrow anterior portion penetrate the intestinal mucosa

25. Trichuris trichiura (Whipworm)
Pathology
light infection : asymptomatic
heavy infection :abdominal pain ,bloody diarrhea. Rectal prolapse in children is a common complication. -

26. Trichuris trichiura (Whipworm)
Embryonated egg Unembryonated egg
Infective stage Diagnostic stage

27. Trichuris trichiura (Whipworm)
-Diagnosis: egg in stool characterized by its barrel shape with mucoid plugs at each pole .
Treatment :Albendazole.

28. Ancylostoma dudenale &Necator americanus
Hook worms
Ancylostoma dudenale &Necator americanus

29. Buccal cavity attached to intestinal mucosa
Hook worms
Buccal cavity attached to intestinal mucosa

30. Ancylostoma dudenale &Necator americanus
Hook worms
Ancylostoma dudenale &Necator americanus
LIFE CYCLE

31. Ancylostoma dudenale &Necator americanus
Hook worms
Ancylostoma dudenale &Necator americanus
A common cause of anemia.
Found in small intestine mainly jejunum.
Its buccal capsule (mouth) lined with hard hooks, triangular cutting plates and anticoagulant glands.

32. Pathology& clinical picture:
Hook worms
Pathology& clinical picture:
- larvae:
At the site of entry of larvae (ground itch).
Migration phase:
cough with bloody sputum
pneumonia, eosinophilia,u rticaria.
- adult worm:
low worm burden: no symptoms.
Moderate to heavy burden:
Epigastric pain, vomiting , hemorrhagic enteritis.
Protein loss: hypoproteinaemia edema.
Anemia: due to withdrawal of blood by parasites and hemorrhage from punctured sites lead to sever anemia = microcytic hypochromic .

33. Diagnosis and treatment
Hook worms
Diagnosis and treatment
Diagnosis:
-Eggs in stools.;
-occult blood (+)
Treatment: Albendazol, Mebendazole

34. Strongyloides stercoralis
Widely distributed in tropical region worldwide .
fetal opportunistic in immuno-compromised host.
It is smallest pathogenic nematodes
± 2.5mm.
adult live in mucous membrane of duodenum jejunum rarely m.m.of bronchus.

35. Strongyloides stercoralis
LIFE CYCLE

36. Strongyloides stercoralis: Pathology and clinical picture:
Cuteneous little reaction on penetration.
sever dermatitis at perianal region in
case of external autoinfection.
Migration :same as hook worms .
Intestinal: inflammation of upper intestinal mucosa, diarrhea, upper abdominal pain clocky in nature.
Disseminated strongyloidiasis : in patient with immunodeficiency ,uncontrolled diarrhea –granulomatus changes –necrosis--perforation--peritonitis--death.

37. Strongyloides stercoralis
Diagnosis:
rhabditiform larvae diagnostic stage in:
-Stool examination
-Duodenal aspirate
Treatment : Albandazole, Mebendazole