1. Parasitic Diseases important in Meat Inspection By Dr. NYAKARAHUKA LUKE (BVM, MPH CANDIDATE)

2. TRICHINELOSIS Etiology – Trichinella spiralis, T. nativa, and T. britovi Hosts – All mammals, principally, pigs, man, rats, etc Life cycle. Clean life cycle. It has no free living stages outside the host. After ingestion, it gets encysted in the muscles Larvae get released from muscles by action of digestive enzymes. Larvae enters the lymphatic system to the circulating system finally back to muscles 5/16/2015Dr. Nyakarahuka2

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4. It is common in developing countries where meat fed to pigs is raw or undercooked 5/16/2015Dr. Nyakarahuka4

5. Trichinellosis Predilection site is Muscles Host reaction can lead to calcification Caused by eating raw or undercooked pork or wild game infected with the larvae Diagnosis – Trichinoscopy tests.Taking a piece of muscle esp diaphragm and compress it between two glass slabs and view on microscope – Artificial Digestion using gastric juices – Serological tests 5/16/2015Dr. Nyakarahuka5

6. Parasite Control Measures Through cooking of meat of meat at a temp not less than 60 o c Freeze at -15 0 c for at least 30 days Avoid feeding swill or garbage to pigs Drying is ineffective, but salting and smoking can be effective 5/16/2015Dr. Nyakarahuka6

7. Judgment for Trichenollosis Total condemnation of the entire carcass 5/16/2015Dr. Nyakarahuka7

8. Taeniasis(Cestodes) Segmented worms that live in intestines Adults release last maturing segments(Progrolitids) can be gravid with over 30,000. These are passed into feces and hatched into larvae on the ground. Larvae are ingested by animals, migrate to their predilection sites to form cystic forms These cystic forms are the ones infective to man. 5/16/2015Dr. Nyakarahuka8

9. Taeniasis 3 types of cyst occur – cysticercus. Has got an outer membrane enclosing a single scolex, each with a varying degree of fluid. – Coenurus(Multiceps cysts), with single cyst and several scoleces – Hydatid cysts(Echinococcus).It contains brood capsules with scoleces –Daughter cysts 5/16/2015Dr. Nyakarahuka9

10. Taenia Solium(Pork tape worm) Final host is man, intermediate host is pig. Larvae is picked by the pig while scavenging It moves through blood stream to the liver and finally to active muscles where it forms cysts. Active muscles include heart muscle, diaphragm, massatter muscles, tongue, abdominal muscles, neck etc. This cystic form is know as cysticercus cellulosae. The condition is know as cyticercosis. Also known as pork measles. 5/16/2015Dr. Nyakarahuka10

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12. T. Solium It can be visible in muscles 4-10 weeks after infection They appear as white sports measuring 16x9.5mm.They look like as if rice is in muscles. In man, it causes neurocysticercosis leading to cns signs, epilepsy 5/16/2015Dr. Nyakarahuka12

13. Pork Measles 5/16/2015Dr. Nyakarahuka13

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15. Cyst in the Peritoneal cavity 5/16/2015Dr. Nyakarahuka15

16. Numerous cysts of C. cellulosae in the heart muscles. 5/16/2015Dr. Nyakarahuka16

17. Cellulosae cysts in the liver. 5/16/2015Dr. Nyakarahuka17

18. C. cellulosae cysts in the brain. 5/16/2015Dr. Nyakarahuka18

19. T. Solium Judgment at Meat inspection If the total number of cysts is more than 6, condemn the whole carcass. Any organ or head or any part of the pig with 1 or more cyst should be condemned. If in extended examination, you find between 1-5 cysts in whole carcass, conditionally approve. Subject the carcass to treatments such as -10 o c for about 2wks Heat treatment-sterilize by heat or boiling at 95- 100 o c for 30 minutes or heat 72 o c for 2hrs 5/16/2015Dr. Nyakarahuka19

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21. Prevention Massive chemotherapy treatment of infected humans, Improving sanitation. Education humans are major ways to discontinue Cooking of pork or freezing it and inspecting meat are effective means to cease the life cycle The management of pigs by treating them or vaccinating them is another possibility to intervene. 5/16/2015Dr. Nyakarahuka21

22. Taenia saginata(Beef Measles) Also called beef-tape worm Or Beef measles Cystic form called cyticercosis bovis Big problem in Africa, asociated with serious economical losses.We can not export meat. Final host is man, intermediate host is bovine(Cattle).Other wild ruminants are infected. 5/16/2015Dr. Nyakarahuka22

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24. Taenia saginata Taenia saginata occurs where cattle are raised by infected humans maintaining poor hygiene, human feces is improperly disposed of, meat inspection programs are poor, where meat is eaten without proper cooking 5/16/2015Dr. Nyakarahuka24

25. Taenia saginata Predilection sites are tongue, heart muscle, massater, adductor muscles, diaphragm and psoas muscles, i.e. active muscles. Occasionally in liver and lungs. The cyst is fully developed 18 wks after ingestion, can be diagnosed at 6 wks, can remain viable even two weeks after death of animal. Uganda Code of Meat inspectors ensure routine inspection of tongue, masseters, heart, adductor muscles, etc 5/16/2015Dr. Nyakarahuka25

26. Taenia saginata Postmortem findings : Small white lesions (cysticerci 2 – 3 weeks after infection) in muscle tissue Clear transparent bladders 5 × 10 mm (infective cysticerci, 12 – 15 weeks after infection, Fig. 91) Opaque and pearl like (over 15 weeks of infection) Degeneration, caseation and calcification (after 12 months or more after infection) Degenerative myocarditis 5/16/2015Dr. Nyakarahuka26

27. C. bovis 5/16/2015Dr. Nyakarahuka27

28. C.bovis 5/16/2015Dr. Nyakarahuka28

29. C. bovis 5/16/2015Dr. Nyakarahuka29

30. C. bovis 5/16/2015Dr. Nyakarahuka30

31. Caseous cysticercus. Numerous clear transparent cysts on the heart surface. 0.6 mm in diameter in the heart muscle 5/16/2015Dr. Nyakarahuka31

32. Cysticercus ovis. The heart of an old ewe showing heavy infestation with C. ovis. The cysts have degenerated and undergone calcification 5/16/2015Dr. Nyakarahuka32

33. Taenia saginata Judgment at meat inspection Condemn the whole carcass if; – the infection is excessive i.e. if any muscle you incise, you find 1 or more cysts or any organ you incise you find 1 or more cysts. – The total number of cysts in any muscle or surrounding tissue or organ exceed 20 just on a single incision – 10 or more cyst in a dressed carcass – 4 or more cysts in the head or organs of vicsera together with 6 or more cysts in the dressesd carcass. 5/16/2015Dr. Nyakarahuka33

34. Taenia saginata Judgment at meat inspection When there is discoloration of the carcass regard less of the number of cysts Conditionally approve if the carcass – Has 1-9 cysts – Any part of the carcass has 1 or 2 cysts 5/16/2015Dr. Nyakarahuka34

35. Echinococcus granulosus Hydatid disease The cystic form is hydatid disease Final host is dog and other caniids Intermediate hosts are cattle, ruminants, pigs, Man is an accidental intermediate host The eggs are released from the dogs into the ground where they are picked The larvae go through the walls of small intestines and finally into the liver, lungs, peritoneal space, even in the brain. 5/16/2015Dr. Nyakarahuka35

36. Adult worm.Echinococcuss 5/16/2015Dr. Nyakarahuka36

37. Hydatid cysts in bovine liver 5/16/2015Dr. Nyakarahuka37

38. Hydatid cyst in Brain 5/16/2015Dr. Nyakarahuka38

39. Hydatid cysts 5/16/2015Dr. Nyakarahuka39

40. Cystic hydatid disease 5/16/2015Dr. Nyakarahuka40

41. Hydatid cysts in bovine heart. Note the detached germinal layer 5/16/2015Dr. Nyakarahuka41

42. In liver of shoats 5/16/2015Dr. Nyakarahuka42

43. hydatidosis 5/16/2015Dr. Nyakarahuka43

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45. Section of hydatid cyst, 5/16/2015Dr. Nyakarahuka45

46. A person affected by hydatid disease 5/16/2015Dr. Nyakarahuka46

47. Judgment at PM The shape of cysts depend on shape and size of organ where the cyst is located. It can be spherical and can be very large Leading to pressure necrosis. Carcass showing emaciation, edema and muscular involvement is condemned and destroyed. Affected viscera condemned and destroyed. Burying of carcass is not sufficient, since dogs may retrieve the affected organs. 5/16/2015Dr. Nyakarahuka47

48. Taenia Hydatigena Its among the largest tape worms of dogs. The cystic form is cysticercus tennuicolis found intermediate hosts which are small ruminants(goats and sheep) and pigs. It is one of the largest cysts up to 7.5 cm with a long thin neck. Predilection sites include the omentum, mesenteries & liver. Its some times cold a bladder worm 5/16/2015Dr. Nyakarahuka48

49. taenia hydatigena 5/16/2015Dr. Nyakarahuka49

50. Cysticercus tenuicollis. Numerous subserosal cysts in the liver 5/16/2015Dr. Nyakarahuka50

51. Taenia Hydatigena The development takes 5-6 weeks Judgment – If infestation is not heavy, since sub-serosally/ remove cyst and pass carcass – In case of excessive infestation, condemn the affected organs. – Man is an accidental host 5/16/2015Dr. Nyakarahuka51

52. Taenia multiceps Cystic form is muliticpes multiceps or also called coenurus cerebralis It exclusively confined to brain tissue of ruminants Can be size of a pea or an egg. It has a transparent wall with many scoleces Animals get infected via contaminated water Can be arrested in liver and die, otherwise reach brain in 8-14 days leading to CNS signs 5/16/2015Dr. Nyakarahuka52

53. Taenia multiceps Final host carnivores Intermediate hosts- ruminants Prevention – Don’t give dogs raw meat Judgment – In early cases when there is no emaciation, condemn the head – If there is emaciation, condemn the whole carcass 5/16/2015Dr. Nyakarahuka53

54. Fascioliasis Caused by Fasciola hepatica, Fasciola gigantica Signs can be acute, sub acute and subclinical At post mortem, acute lead to parachymatous hepatitis, hemorrhages and fibrin on capsule. The liver has numerous sharp small lesions, which on pressure exudes semi fluid necrotic liver tissues and mature flukes. Although acute cases are rare 5/16/2015Dr. Nyakarahuka54

55. Fascioliasis Chronic form most common Bile ducts are thickened, dilated, calciferous Bile ducts filled yellowish brown bile containing flukes which can be expressed when ducts are incised. Excessive calcification and fibrosis of ducts leads to liver cirrhosis. Migrating flukes may reach other organs like lungs 5/16/2015Dr. Nyakarahuka55

56. Numerous flukes of Fasciola hepatica observed in the bile ducts and liver parenchyma of a cow. 5/16/2015Dr. Nyakarahuka56

57. Liverfluke 5/16/2015Dr. Nyakarahuka57

58. Acute haemorrhagic tract in the bovine liver. 5/16/2015Dr. Nyakarahuka58

59. Fascioliasis. Black parasitic debris in the liver 5/16/2015Dr. Nyakarahuka59

60. Fascioliasis Judgment Markedly cirrhotic liver should be condemned Affected liver can be consumed for pet food Or as inedible by-products or Using in pharmacological industries for producing heparin or Vit.B12 Otherwise mildly affected liver can trimmed and pass the rest. 5/16/2015Dr. Nyakarahuka60

61. Reading assignment Read and make notes on; – Lung worms eg (Dictyocaulus viviparus – Linguatura larvea – Oesophagostomiasis – Ascariasis 5/16/2015Dr. Nyakarahuka61