parasitology

2. parasitology • Medical Parasites: • - Protozoa 1- Platyhelminthes • - Helminthes: 2- Nemathelminthes • - Arthropoda 3- Nematomorpha • 4- Acanthocephala • 5- Annelida

3. WHO Classified of Helminthes According to transmission methods • 1- Soil transmitted Helminthes : Ascaris, Hook worms • 2- Snail t. H. : Trematoda( Schistosoma,….) • 3- Arthropods t. H. : Filaria, Dracanculus medinensis • 4- Food and Meat t. H. : Taenia saginata, Taenia solium • 5- Direct t. H. ( contagious H.):Enterobius vermicularis,…

4. Nematoda General Discription Morphology

5. Reproductive system

6. Digestive system Bucal cavity

7. Classification of Nematoda • Nematoda: 1- Phasmidia (Secerenentea) • 2- Aphasmida (Adenophora): • ويژگيهاي آفازميدا: • تحليل يافقدان پاپي هاي دمي • -سيستم دفعي- ترشحي فاقد كانالهاي جانبي • - مري سيلندري شكل واجد استيكوزوم يا تروفوزوم • - تخمهاي بد ون سگمانته با پلاكهاي قطبي • - لارو مرحله L1 عفونتزا و اغلب واجد Stylet • - فاقد فاسميد

8. Order: Enoplida • 1- Super Family: Trichoridea • Genus: - Trichuris • - Trichinella • - Capillaria • - Anatrichosoma • 2- Super Family: - Dioctophymatoidea • Genus: - Dioctophyma • 3- Super Family: - Mermithoidea

9. ويژگيهاي Super Family: Trichroidea • جنس نر وماده مجزا • قسمت قدامي ظريف و قسمت خلفي پهن • كرم نر واجد 1 اسپيكول يا فاقد آن • ماده مونودلفيك • مري واجد استيكوزوم • روه وركتوم بخوبي تكامل يافته

10. Trichuris trichiura( also called the human whipworm)

11. Life Cycle

13. Geographic Distribution • The third most common round worm of humans.  • Worldwide, with infections more frequent in areas with tropical weather and poor sanitation practices, and among children.  • It is estimated that 800 million people are infected worldwide.

14. Clinical Features • Most frequently asymptomatic.  • Heavy infections, especially in small children, can cause gastrointestinal problems (abdominal pain, diarrhea, rectal prolapse) and possibly growth retardation

15. Whipworm in the gut

16. Prolapsed Rectum

18. Laboratory diagnosis • Microscopic identification of whipworm eggs in feces is evidence of infection. 

19. Treatment • Mebendazole is the drug of choice, with albendazole as an alternative

20. Causal Agents:Trichinellosis (trichinosis) is caused by nematodes (roundworms) of the genusTrichinella.  • In addition to the classical agentT. spiralis (found worldwide in many carnivorous and omnivorous animals), several other species ofTrichinellaare now recognized.

21. Trichinella spp. • 1- T. pseudospiralis(mammals and birds) worldwide), • 2- T. nativa(Arctic bears) • 3- T. nelsoni(African predators and scavengers) • 4-T. britovi)carnivores of Europe and western Asia).

23. Trichinella-adult

24. Trichinellanativa

25. Life cycle

27. Geographic Distribution • Worldwide.  Most common in parts of Europe and the United States.

28. Clinical Features • Light infections may be asymptomatic.  • Intestinal invasion can be accompanied by gastrointestinal symptoms (diarrhea, abdominal pain, vomiting).  • Larval migration into muscle tissues (one week after infection) can cause periorbital and facial edema, conjunctivitis, fever, myalgias, splinter hemorrhages, rashes, and blood eosinophilia.  • Occasional life-threatening manifestations include myocarditis, central nervous system involvement, and pneumonitis.  • Larval encystment in the muscles causes myalgia and weakness, followed by subsidence of symptoms.

29. Splinter hemorrhages Swollen eyes

30. A, B:Encysted larvae ofTrichinellain pressed muscle tissue sample.  The coiled larvae can be seen inside the cysts

31. Trichinella spiralisencysted larva

32. C, D:Larvae ofTrichinella, freed from their cysts, typically coiled; length: 0.8 to 1 mm. 

33. Antibody Detection • Immunodiagnostic tests currently available in the U.S. include enzyme immunoassays (EIA).  • Antigen preparations may be crude antigens prepared from homogenates ofTrichinella spiralismuscle larvae or excretory-secretory (ES) products produced by cultured larvae.

34. Laboratory Diagnosis • The suspicion of trichinellosis (trichinosis), based on clinical symptoms and eosinophilia, can be confirmed by specific diagnostic tests, including antibody detection, muscle biopsy, and microscopy.

35. Trichuris trichiura( also called the human whipworm)

36. Life Cycle

37. Capillaria spp. • Causal Agents:The nematode (roundworm)Capillaria philippinensiscauses human intestinal capillariasis.  • Two otherCapillariaspecies parasitize animals, with rare reported instances of human infections.  They areC. hepatica, which causes in humans hepatic capillariasis, andC. aerophila, which causes in humans pulmonary capillariasis.

38. The adults ofCapillaria philippinensis(males: 2.3 to 3.2 mm; females: 2.5 to 4.3 mm) Larvae of Capillaria philippinensis

39. Capillaria philippinensisegg under light microscopy. Roll over the image for a view of unembryonatedC. philippinensiseggs inside an adult female.

40. Life Cycle

41. Geographic Distribution • Capillaria philippinensisis endemic in the Philippines and also occurs in Thailand. •   Rare cases have been reported from other Asian countries, the Middle East, and Colombia.  • Rare cases of human infections withC. hepaticaandC. aerophilahave been reported worldwide.

42. Capillaria aerophila • adult worms reside in the epithelium of the tracheo-bronchial tract of various animals.  Eggs are produced, coughed up, swallowed by the animal, and excreted in its feces.  The eggs become embryonated in the soil.  Ingestion of infective eggs completes the cycle.  Transport or paratenic hosts may also intervene in the cycle.

43. Capillaria hepatica • adult worms reside in the liver of various animals, especially rats.  The females produce eggs that are retained in the liver parenchyma.  When the infected animal is eaten by another animal, the eggs are released by digestion, excreted in the feces of the second animal, and become embryonated in the soil.  Alternately, the eggs can be released following the death and decomposition of the first animal, and mature in the soil.  Following ingestion by a subsequent host, these infective eggs release larvae in the intestine that migrate through the portal circulation to the liver, where they develop into adults.

45. Capillaria hepaticaeggs Capillaria hepaticaeggs in tissue. The egg inD(higher magnification) has a typically striated shell and shallow polar prominences

46. Capillaria hepaticaeggs in livertissue

48. Clinical Features • Intestinal capillariasis (caused byC. philippinensis)manifests as abdominal pain and diarrhea, which, if untreated, may become severe because of autoinfection.  • A protein-losing enteropathy can develop which may result in cachexia and death.  • Hepatic capillariasis(C. hepatica)manifests as an acute or subacute hepatitis with eosinophilia, with possible dissemination to other organs.  It may be fatal.  • Pulmonary capillariasis(C. aerophila)may present with fever, cough, asthma, and pneumonia, and also may be fatal.

49. Laboratory Diagnosis • The specific diagnosis ofC. philippinensisis established by finding eggs, larvae and/or adult worms in the stool, or in intestinal biopsies.  • Unembryonated eggs are the typical stage found in the feces.  In severe infections, embryonated eggs, larvae, and even adult worms can be found in the feces. • The specific diagnosis ofC. hepaticainfection is based on demonstrating the adult worms and/or eggs in liver tissue at biopsy or necropsy.  • (Note: identification ofC. hepaticaeggs in the stool is a spurious finding, which does not result from infection of the human host, but from ingestion by that host of livers from infected animals.) • The specific diagnosis ofC. aerophilais based on demonstrating eggs in stool or in lung biopsy

50. Microscopy Capillaria philippinensiseggs.  These unembryonated eggs are peanut shaped and measure 36 to 45 µm in length by 21 µm in width. They have two inconspicuous polar "plugs" and a striated shell.