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Med Helmenths Lec 3rd.


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Medical college lectures: Medical helminths 3nd year.

Med Helmenths Lec 3rd.

  1. 1. Helmentic infections: Dr.Mohamad Shaikhani.
  2. 2. Helmenths: <ul><li>Roundworms(Nematodes). </li></ul><ul><li>Human intestinal nematodes(enterobius vermicularis, Ascaris,Necator, Ancylostma, strongylodes). </li></ul><ul><li>Tapeworms(cestodes). </li></ul><ul><li>Intestinal: Tenia,diphylobothrium,hymenolepis. </li></ul><ul><li>Tissue cysts & worms: echiniccoccus(hydatid cysts), tenia solum(cysticercosis). </li></ul><ul><li>Trematodes(flukes). </li></ul><ul><li>Blood:Shistosoma(bilharzia). </li></ul><ul><li>Lung:paragonimus. </li></ul><ul><li>Hepatobiliary:Fasciola. </li></ul><ul><li>Intestinal:Fasciolopsis. </li></ul>
  3. 3. Roundworms(Nematodes). Thread worms(enterobius vermicularis) <ul><li>Life cycle: mouth, small inetstine, colon. </li></ul><ul><li>Clinial features: Ova around the anus(pruritis),in females genetalia,autoinfection common. </li></ul><ul><li>Diagnosis:Ova deteted by adhesive celophane tape on perineum or perianal swab. </li></ul><ul><li>Management: Treat all infected family, clothes laundered & nails kept short. </li></ul>
  4. 5. Roundworms(Nematodes). Round worms(asaris lumbricoides) <ul><li>Life cycle: mouth, small inetstine,lungs, small intestine. </li></ul><ul><li>Clinial features: abdominal pain, if heavy malnutrition, I.O, Jaundice, appendisitis, passed by mouth or rectum. </li></ul><ul><li>Diagnosis:Ova in faeces, adult worm passes or seen on OGD, Ba. </li></ul><ul><li>Management: Drugs, surgery for obstruction. </li></ul>
  5. 6. Roundworms(Nematodes). Round worms(asaris lumbricoides)
  6. 8. Roundworms(Nematodes). Wip worms(Trichuris trichura) <ul><li>Life cycle: mouth, small inetstine, colon. </li></ul><ul><li>Clinial features: Asymptomatic, diarrhea, rectal prolapse, growth retardation. </li></ul><ul><li>Diagnosis:Ova in faeces, adult worm passes or seen on OGD, Ba. </li></ul><ul><li>Management: Drugs, personal hygein. </li></ul>
  7. 10. Roundworms(Nematodes). Hook worms( Ancylostomiasis) <ul><li>Life cycle: larva in soil penitrate skin, lungs, bronhi, swallowed, SI. </li></ul><ul><li>Clinial features: Dermatitis, pulmonary infiltration with cough & even hemoptysis, epigastric pain, ulcer – like symptoms, anemia due to blood loss, malnutrition. </li></ul><ul><li>Diagnosis:Ova in faeces. </li></ul><ul><li>Management: Drugs, blood & iron. </li></ul>
  8. 12. Treatment for common intestinal nematodes. - - +++ - + Pyrvinium - - + + +++ Levamisole +++ + ++ ++ ++ Thiabendazole ++ + + ++ ++ Albendazole + ++ +++ ++ ++ Mebendazole - +++ - - - Oxantel - - +++ ++ +++ Pyrantel - - +++ + +++ Piperazine Strongyloides Trichuris E.V Hook Asaris
  9. 13. Cestodes(Tape worms). Taenia saginata: <ul><li>Acquired by eating uncooked beef meat. </li></ul><ul><li>Giant , several meters long. </li></ul><ul><li>Ova of T.saginata & solium are the same. </li></ul><ul><li>Adult worm live in SI. </li></ul><ul><li>Mainly asymptomatic. </li></ul><ul><li>Segments are passed with stools or seen on clothes. </li></ul><ul><li>Praziquantel is the drug of choice. </li></ul><ul><li>Niclosamide is also used. </li></ul><ul><li>Prevention: beef inspection & Cooking . </li></ul>
  10. 14. Cestodes(Tape worms). Taenia solium & cysticercosis: <ul><li>Acquired by eating uncooked pork meat. </li></ul><ul><li>Smaller than saginata . </li></ul><ul><li>Adult worm live in SI. </li></ul><ul><li>Mainly asymptomatic. </li></ul><ul><li>Segments are passed with stools or seen on clothes. </li></ul><ul><li>Praziquantel is the drug of choice for intestinal worms. </li></ul><ul><li>Niclosamide is also used. </li></ul><ul><li>Prevention: pork meat inspection & Cooking, personal hygiene to avoid autoinfection by ova which leads to ystcercosis . </li></ul>
  11. 15. Cestodes(Tape worms). Taenia solium & cysticercosis: <ul><li>Cysticercosis: the larva acquired by ova autoinfetion or regurgitation from the adult worm in the intestine ,may penitrate the stoamch wall & go to develop as cysts in muscles, skin&brain(epilepsy,hydrocephalus). </li></ul><ul><li>Diagnosis: ova in stool, CT & MRI for brain cysts,ELISA test for antibody detection. </li></ul><ul><li>Treatment of cysticercosis is by praziquantel or albendazole combined with prednisolone to prevent brain edema & antiepilepti drugs are given to prevent fits untill full recovery. </li></ul>
  12. 16. Cestodes(Tape worms). Echinococcus granulosus & multilocularis(hydatid cysts): <ul><li>Acquired by ingesting ova passed with dogs(granulosus type) or wild animal faeces( foxes, wolves in multilocularis type) into green vegetables which develop into cysts in the liver, lungs, bones, brain or any other body sites . </li></ul><ul><li>The multilocularis type behaves as malignant disease. </li></ul><ul><li>Prevention: Treatment of Domestic dogs, washing of vegetables. </li></ul><ul><li>Diagnosis: chest X ray, U/S, CT, MRI to detect cysts in tissues, CF test & ELISA to detect parasite antigenes. </li></ul><ul><li>Surgery to remove cysts. </li></ul>
  13. 17. Cestodes(Tape worms). Echinococcus granulosus & multilocularis(hydatid cysts): <ul><li>Drugs are not so effective, although albendazole in high doses for long time & praziquantel are given perioperatively to reduce spillage & in inoperable cases. </li></ul>
  14. 18. Humans Accidental Intermediate Host
  15. 22. Cestodes(Tape worms). Echinococcus granulosus & multilocularis(hydatid cysts):
  16. 23. Cestodes(Tape worms). Echinococcus granulosus & multilocularis(hydatid cysts): Scolex Adult worm Taenia saginata Infected beef
  17. 27. <ul><li>D. latum is the longest tapeworm in humans usually located in the lower jejunum or upper ileum. </li></ul><ul><li>A typical worm is 4–15 m in length, 10–20 mm in width. </li></ul><ul><li>It has an elongated scolex with two sucking grooves, a thin neck & 3000–4000 proglottids, produce up to 1 million eggs each day that excreted into the intestinal lumen & passed in feces. </li></ul><ul><li>The life-cycle is relatively complex, involves larval stages that develop in water & in two intermediate hosts, fresh water crustaceans& fish. </li></ul><ul><li>Humans are infected by eating raw fish. </li></ul>
  18. 28. <ul><li>Human cases restricted to Northern Europe, Canada , Alaska. </li></ul><ul><li>Can be single or multiple& may result in symptoms as fatigue, weakness, parasthesia, diarrhea&craving for salt. </li></ul><ul><li>2% develop vit B12 deficiency, because of B12 absorption by the adult worms & interference with the ileal absorption of cobalamins. </li></ul><ul><li>Diagnosis: made by the detection of eggs in feces </li></ul><ul><li>Treated with a variety of drugs including praziquantel. </li></ul><ul><li>Prevention: The infective larval forms in fish (plerocercoids), can be readily killed by cooking fish at 55°C for 5 min or by freezing for 8–72 h. </li></ul>
  19. 29. Trematodes(Fluke). Shistosomiasis (Bilharziasis): <ul><li>One of the most common causes of morbidity & mortality in tropical areas, S.Hematobium in Iraq & other areas of middle east, S.Mansoni in Egypt & other parts of Africa & S. Japonicum & Mekonji in south east Asia. </li></ul><ul><li>Acquired by walking bare feet in water containing the infective form cercaria. </li></ul><ul><li>Patients excrete the eggs by urination in water whih are hatched & develop in fresh water snails into the infective stage ceraria. </li></ul><ul><li>After penitrating the skin, it goes throught he lungs, then caried by the blood to their definte site where they live, the vesial plexus of veins in Hematobium & the portal system & liver in other types. </li></ul>
  20. 30. Trematodes(Fluke). Shistosomiasis (Bilharziasis):
  21. 32. Trematodes(Fluke). Shistosomiasis (Bilharziasis): pathogenesis & clinical features. Colitis,hepatitis, Portal HT Same. Cystitis, hematuria Immune complex glomerulonephritis. Months. Early egg deposition. Same. Pneumonitis,myositis,hepatitis,fever,eosinophilia,seroconversion. Weeks Larval migration& maturation. Same Papular dermatitis. Days Cercarial penitration Other types. S.Hematobium Time Stage
  22. 33. Trematodes(Fluke). Shistosomiasis (Bilharziasis): pathogenesis & clinical features. Colonic polyposis & strictures,periportal firosis, portal hypertension. Same. UB, ureters fibrosis calcification,Ca Infection,stones,hydronephrosis. Pulmonary granulomas & pulmonary hypertension. Years. Late egg deposition. Other types. S.Hematobium Time Stage
  23. 34. Trematodes(Fluke). Shistosomiasis (Bilharziasis): Diagnosis. <ul><li>Urine & stool exam for terminal spined eggs in hematobium & lateral spined eggs in other types. </li></ul><ul><li>Retal spine biospsy through proctoscpe or biopsy through sigmoidoscope for egg inspection. </li></ul><ul><li>Radiography & U/S for complications. </li></ul><ul><li>ELISA test of blood to detect shistosomal antigenes. </li></ul>
  24. 35. Trematodes(Fluke). Shistosomiasis (Bilharziasis): Treatment. 7.5mg/kg every 2 weeks * 3 Not useful 40mg/kg once Hematobium Not useful Not useful 40mg/kg*2 in one day Japonicum Not useful 15mg/kg*2*2 days 40mg/kg once Mansoni Metrifonate Oxamniquine Praziquantel Type
  25. 36. Trematodes(Fluke). Shistosomiasis (Bilharziasis): prevention. <ul><li>Avoid urination & defecation in water. </li></ul><ul><li>Erradication of snails. </li></ul><ul><li>Wearing of boots when contacting water. </li></ul><ul><li>Store water for 3 days before use as cercaria will die in 3 days. </li></ul><ul><li>Mass treatment of population. </li></ul><ul><li>All these are not beneficial in japonicum as there are other animal reservior of infection which contaminate water by eggs. </li></ul>
  26. 37. A: Acute liver granuloma around S mansoni egg in liver. B: Chronic liver granuloma around the remains of a schistosome egg in liver, with dominant fibrous tissue.
  27. 38. C: Macrohaematuria due to ulceration of the bladder wall in urinary schistosomiasis. D: Ultrasonography of irregular bladder wall and polyp; E: IVP showing bilateral hydroureter and hydronephrosis.
  28. 39. F: Severe bloody diarrhoea due to S mansoni . G: 6-year-old boy with gross hepatosplenomegaly. H: 19-year-old man with symptoms of chronic fibrotic liver schistosomiasis—splenomegaly, external varices, ascites, growth retardation. I: ultrasonography of advanced periportal fibrosis &portal venodilatation;