Clinical Parasitology - 03 Trematodes

• CLINICAL PARASITOLOGY TREMATODES OUTLINE • • Trematodes o Introduction & Taxonomy o Trematodes o Life Cycle Liver, Intestinal, Pancreatic, and Lung Flukes o Liver Flukes ▪ Fasciola Hepatica & • Fasciola gigantica ▪ Clonorchis sinensis, Opistorchis felineus ▪ Dicrocoelium dendriticum/lanceolata Attach themselves to the host by means of 2 suckers o Oral sucker o Ventral sucker (acetabulum) o 3rd sucker (Genital sucker - gonocytes) – Heterophyes spp o o Intestinal Flukes Pancreatic Flukes: Eurytrema pancreaticum o Lung Flukes: Paragonimus Westermani Blood Flukes o Schistosomes o Other Schistosomes o Pathology o Diagnosis LIFE CYCLE • • • Legend: → (Example) Eggs o Has Operculum – lid-like structure ▪ Opens if the larva inside the egg is already ready to hatch Larva (5 sub-stages): o Miracidium - water o Sporocyst, Redia, Cercaria - 1st Intermediate host o Metacercaria - 2nd intermediate host o ‘My Sister Rent a Car for Me’ Adults o Female: Oviparous or Oviviparous TREMATODES LIVER, INTESTINAL, PANCREATIC, AND LUNG FLUKES INTRODUCTION & TAXONOMY LIVER FLUKES: Fasciola Hepatica & Fasciola gigantica Common Name TREMATODES • • • • • • • • • Flukes Leaf-like in shape Has incomplete alimentary canal and complex reproductive structures o Alimentary canal - digestive system o Incomplete alimentary canal due to absence of anus o Complex reproductive due to presence of testis, ovary, and uterus in single adult Monoecious - both male and female (hermaphroditic) Infective stage: Metacercaria (larval stage) o For most trematodes except for order Strigeiformes Mode of transmission: Ingestion of the 2nd intermediate host infected with Metacercaria Has 3 hosts (2 Intermediates & 1 Definite) Requires 2 Intermediate hosts: o 1st Intermediate Host: Snail o 2nd Intermediate Host: Fish, Crabs, Vegetation, Snail Definitive Host: Man Fasciola Hepatica Sheep Liver Fluke Fasciola gigantica Giant Liver Fluke Temperate Liver Fluke Sheep Tropical Liver Fluke Natural/Final Local cattle, Host herbivores 1st Intermediate Snails: Lymnea philippinensis, Lymnea Host auricularia rubiginosa (snail) 2nd Intermediate Vegetation: Ipomea obscura (kangkong) & Host Nasturtium officinale (water cress) Habitat Liver parenchyma, (gall bladder) Infective Stage Metacercaria Pathology Fascioliasis (liver rot), liver atrophy, halzoun Laboratory Stool exam, liver biopsy, PCR Diagnosis Drug of Choice Bithionol, Triclabendazole • F. gigantica - largest liver fluke • Man - accidental host for Fasciola • Stool exam - due to transmission by ingestion • Liver biopsy - due to tendency of Fasciola to affect liver • PCR - detect genetic sequence of Fasciola LIFE CYCLE • • Eggs become embryonated in water Infective stage - 1st IH: Miracidia Adult Larva Egg Fasciola Hepatica with cephalic cone which has well developed shoulder Fasciola gigantica Larger than F. hepatica, less developed shoulder, shorter cephalic cone Final Host 1st Intermediate Host 2nd Intermediate Host All stages are present EGG Large, operculated, unembryonated, yellowishbrown egg (Hen’s egg shape) Habitat Infective Stage Pathology Laboratory Diagnosis Drug Of Choice PATHOLOGY • • Human Fascioliasis – Sheep Liver Rot o Acute or Invasive Phase ▪ Larval migration and worm maturation in the hepatic tissues ▪ May appear asymptomatic ▪ Migration of fluke from the intestine to the liver ▪ Flukes burrows through the liver parenchyma producing traumatic and necrotic lesions o Chronic phase ▪ Period where fluke already reached the bile ducts ▪ Adult flukes can cause obstruction and stimulates inflammation in the biliary epithelium which subsequently cause fibrosis. ▪ Only diagnosed during surgery o Triad of Diagnostic Significance ▪ Symptoms that are correlated with sheep liver rot ▪ Sudden onset of fever ▪ Hepatomegaly - enlargement of liver ▪ Marked eosinophilia - increased eosinophils “Halzoun” (Mararra) o Halzoun from Lebanon, Mararra from Sudan o Pharyngeal suffocation o suffocation as a result of temporary lodgment of the fluke in the pharynx DIAGNOSIS • • • • LIVER FLUKES: Clonorchis sinensis & Opistorchis felineus Clonorchis sinensis Opistorchis felineus Oriental Liver Fluke Cat Liver Fluke Chinese Liver Fluke Siberia Liver Fluke Most important liver First described by fluke of man McConnell Possible carcinogen Praziquantel, Albendazole CA - carcinoma LIFE CYCLE ADULT Stool Exam (Direct Fecal Smear) Recovery of adult worms in duodenal contents and bile o Adults reside in liver Liver Biopsy Molecular methods (PCR) Common Name Notes • Clonorchis sinensis Opistorchis felineus *Opistorchis viverrini – Southeast Asian liver fluke Man and other fishCats eating vertebrae Snails: Family Snails: Family Parafossarulus, Bithynia Bulinus, Semisulcospira, Alocinma, Thiara, Malanoides Family Cyprinidae Family Cyprinidae (Fishes) (Fishes) Family Cobitidae (Fishes) Liver parenchyma (also in pancreatic duct and gallbladder - C. sinensis) Metacercaria Bile duct obstruction, Liver CA, and gallbladder CA Stool exam, serologic tests, molecular tests Clonorchis sinensis Opistorchis felineus Leaf-like with transparent tegument Vitellaria (VT) found in the middle third of the body Two large, highly branched Lobate testes testes (TE) arranged in arranged obliquely tandem EGG • • • • Yellowish-brown, ovoid (Pitcher-shaped/Oldfashioned electric light buld-shaped) Distinct convex operculum that fits to the thickened rim of the eggshell Thick rim located around operculum (shoulders) Small protuberance at the abopercular end PATHOLOGY • • • Periductal fibrosis o Fatigue, weakness, weight loss, altered appetite Gallbladder and Liver CA o Hepatocellular Carcinoma o Cholangiocarcinoma o Due to carcinogenic nature Liver dysfunction o Clonorchis sinensis o Occurs on person severely infected over a long period of time Fasciolopsis buski • Bamboo shoots (Zizania) Habitat Infective Stage Pathology Laboratory Diagnosis Drug Of Choice DIAGNOSIS • • • Stool Exam (Direct Fecal Smear) o Detection of egg Serologic test (ELISA, EIA) o ELISA - Enzyme-linked Immunosorbent Assay o EIA - Enzyme Immunoassay Molecular methods (PCR) LIVER FLUKES: Dicrocoelium dendriticum/lanceolata • • • • • • • • • • • Common Name: Lanceolate/Lancet Fluke Habitat: Biliary passage of the liver Final Host: Cattle/Sheep o Man - accidental host 1st IH: Snail (Cochlicopa, Helix, Xerolenta, Zebrina) 2nd IH: Ants (Formica fusca) Infective stage: Metacercaria Mode of Transmission: Ingestion of 2nd IH w/ Metacercaria Egg: Brownish, thick-walled, operculated, embryonated Adult: Lancet-shaped Pathology: Cirrhosis/Fibrosis of the liver Dicrocoelium hospes – responsible for human infection in West Africa • • Echinostoma ilocanum Heterophyes heterophyes Small Intestine Metacercaria Abdominal Abdominal Abdominal pain, discomfort, discomfort, Mucous Diarrhea, Chronic mucous diarrhea, Edema diarrhea, Ulceration of Eosinophilia intestinal wall Stool Exam, Concentration techniques, Molecular techniques (PCR) Praziquantel H. heterophyes - deadliest because they may end up in circulation that may transfer to heart, brain, & spinal cord o Once in the heart, can cause heterophyid myocarditis (account for 15% of fatal heart disease in the PH) o Transport to circulation through ulceration of intestinal wall Concentration technique - for recovery of eggs LIFE CYCLE Fasciolopsis buski Echinostoma ilocanum ADULT Has simple intestinal Circumoral disk ceca Two dentritic with crown of testes in tandem spines (49-51 Branched ovaries spines) surrounding the oral sucker EGG Heterophyes heterophyes Has genital sucker surrounding the genital pore *Has genital sucker (gonocyte) – 3rd sucker Indistinguishable Germ ball egg with Old-fashioned light from other fasciolid triangular bulb eggs operculum INTESTINAL FLUKES Fasciolopsis Echinostoma buski ilocanum Common Giant Intestinal Garrison’s Fluke Name Fluke Notes Largest fluke Discovered by parasitizing man Philip Garrison (in general) among prisoners of Bilibid Prison in Manila, PH Final Host Man 1st Segmentina, Gyraulus intermediate Hippeutis convexiusculus; host Hippeutis (Snails) umbilicalis 2nd Vegetation Snail intermediate • Water Caltrop • Kuhol (Pila host (Trapa luzonica) bicornis) • Susong • Water Chesnut pampang (Eliocharis (Vivipara tuberosa) angularis) • Kangkong/ Morning Glory (Ipomea obscura) • Lotus (Nymphaea lotus) Heterophyes heterophyes Von Siebold’s Fluke • Smallest trematode of man • Deadliest trematode Cerithidea, Pirenella Fishes • Balanak – Mugil spp • Tilapia – Tilapia spp • Kanduli – Arius manilensis • Common in the Philippines PANCREATIC FLUKES: Eurytrema pancreaticum • • • • • • • • • Common Name: Pancreatic fluke Habitat: Pancreatic ducts Final Host: Cattle/Sheep 1st IH: Snail 2nd IH: Ants, Grasshoppers, Mantis, Crickets Infective stage: Metacercaria Mode of Transmission: Ingestion of 2nd IH w/ Metacercaria Egg: Operculated, embryonated (same w/ D. dendriticum) Adult: Ruffled margins LUNG FLUKES: Paragonimus westermani • • • • • Common Name: Oriental Lung Fluke Common in Sorsogon, Bicol Habitat: Lungs Final Host: Man 1st IH: Snail o Antemelania asperata (formerly Brotia asperata) o Antemelania dactylus • • • • 2nd IH: Crabs o Sundathelpusa philippina (formerly Parathelpusa grapsoides) Infective stage: Metacercaria Mode of Transmission: Ingestion of 2nd IH w/ Metacercaria Treatment: Praziquantel • • • • LIFE CYCLE Stool exam (DFS) o Infected individual (children) may ingest infected sputum which may pass through the digestive system Chest X-ray Serodiagnostics (ELISA, IB) o IB - immunoblot Molecular tests (PCR) BLOOD FLUKES Schistosomes • • • • • • • • • ADULT • Coffee-bean shaped • Wavy or succulent intestinal ceca EGG • Thickened abopercular end • Flattened but prominent operculum • Similar w/ Diphylobotrium latum • Schistosoma Schistosoma japonicum mansoni Common Oriental Blood Mansoni Blood Name Fluke Fluke Notes Common in First reported by Mindoro, Leyte, Theodore Bilharz Sorsogon, Mindanao Smallest among blood flukes Final Host Man 1st Oncomelania Biomphalaria intermediate hupensis spp., host quadrasi Australorbis (Snails) spp., Tropicorbis spp. Planorbis spp. Habitat Superior Inferior mesenteric vein mesenteric vein Colon/rectum PATHOLOGY • • • • • Paragonimiasis (Pulmonary distomiasis) o Chronic cough and hemoptysis (blood in sputum) o Present as symptoms of tuberculosis Chronic bronchiectasis Pleural fibrosis Cutaneous Paragonimiasis o Slow moving nodular lesions in the subcutaneous tissues on the abdomen and chest Cerebral Paragonimiasis o Most serious complication among man o Diplopia – simultaneous perception of two images of a single object (pagkaduling) o Hemiparesis – weakness of one side of the body o Homonymous hemianopsia – condition where a person sees only one side (either left or right) o Aphasia – impairment of language (cannot speak, read or write) o Headache, Seizures, Blurring of Vision Infective Stage Mode of Transmission Pathology Laboratory Diagnosis Drug of Choice DIAGNOSIS • Sputum examination o Ova + Charcot-Leyden crystals (eosinophil degradation products) Elongated/cylindrical Dioecious - adult can only be male or female, not both Only one Intermediate host: Snail Definitive Host: Man Infective stage: o Miracidia - infect snail (IH) o Cercaria - fork-tailed cercaria; for definitive host Mode of transmission: Skin penetration of cercaria Adults: o Always in copula (perpetual copulation) ▪ The most romantic parasites o Female: Oviviparous o Male: have gynecophoral canal/grooves ▪ Gynecophoral canal - where female is held Eggs: non-operculated Larva: No Redia and Metacercaria o Miracidia → Sporocyst → Cercaria Habitat: o ADULT: Blood Vessels ▪ Ingests RBCs ▪ Contains proteases such as hemoglobinase (breaks down hemoglobin) • Schistosoma haematobium Vesical Blood Fluke Common in Nile River Valley Bulinus spp. Physopsis spp. Biomphalaria spp. Vesical, prostatic, uterine venous plexuses Urinary Bladder Cercaria (forked tail) Skin penetration Katayama Intestinal Urinary Disease, Snail Bilharziasis Bilharziasis, fever, Oriental Egyptian Schistosomiasis, hematuria, Swamp fever Bloody Urine Stool examination, Concentrated rectal biopsy specimen urine specimen Praziquantel; Metrifonate (Bilarcil) – alternative for S. HaematobiumI (for resistance) Stool exam - due to presence in mesenteric veins • Conc. urine specimen exam - from 24 hour urine sample (patient collect voided urine within 24 hour span) • LIFE CYCLE • • • • • • • When cercaria penetrates skin, it loses its tail Schistosomule - tail-less cercacia Schistosoma japonicum Schistosoma mansoni Schistosoma haematobium ADULT EGG • 3000 eggs/day Large, prominent • 100-300 terminal spine eggs/day • With knob-like or curved hook of • Light yellowish protuberance on brown with large one-side (Lateral lateral spine on knob) one side (rosethorn • Smallest egg of appearance) all schistosoma • • DIAGNOSIS • Adults are not diagnostically important OTHER SCHISTOSOMES • Schistosoma mekongi o Discovered in Mekong River o Eggs resembles egg of S. japonicum, but smaller o Adults reside in small intestine venules • Schistosoma intercalatum o Eggs resemble egg of S. haematobium but with equatorial/central bulge o Adults reside in colon venules (large intestine) o Can be found in stool sample PATHOLOGY • Swimmer’s itch/Gulf-coast itch/Cercarial itch, Clam digger’s itch o Dermatitis with pruritus at the site of cercarial penetration Katayama disease/Katayama Fever/Snail Fever o systemic hypersensitivity reaction to schistosomulum migrating through tissue (can move to intestinal, hepatosplenic, pulmonary, cerebral tissues) Intestinal schistosomiasis – eggs are deposited in the intestinal mucosa triggering granuloma formation (obstruction of intestinal tract) Hepatosplenic schistosomiasis – the most serious consequence of chronic schistosomiasis o Hepatomegaly, Ascites, Portal Hypertension and development of collateral circulation Pulmonary schistosomiasis – larval migration to lungs o Wheezing and coughing o Can lead to cor pulmonale - right-sided heart enlargement Cerebral schistosomiasis – motor and sensory disturbances For S. haematobium o Urinary Schistosomiasis – “sandy patches” in the lower urinary tract o Female Genital Schistosomiasis – associated with presence of eggs in the cervix, vagina and/or vulva o Obstructive uropathy – due to deposition of eggs in the ureter wall obstruction urinary flow o Bladder Calcification – calcium deposition around schistosome eggs in the urinary bladder ▪ “Fetal head” sign in abdominal X-ray o Bladder Carcinoma - most prevalent among Egyptians ▪ May be due to continuous exposure to carcinogens secondary to bacterial infections (Nnitroso compounds) *Picture taken by Dr. Belizario de Leon, well known parasitologist in the Philippines • For o o o o o S. japonicum and S. mansoni Stool examination Rectal biopsy - common for S. mansoni Sedimentation techniques - for heavy eggs Faust-Meleney’s Egg Hatching Technique Circumoval Precipitin Test (COPT) ▪ Definitive test for Schistosomiasis ▪ Demonstrates “bleb formation” ▪ Specimen: Serum (to detect antibodies) ▪ Reagent: Lyophilized (powdered) eggs from rabbits o Cercarial Hullen Reaction ▪ Demonstrates shrinking of cercaria ▪ Specimen: Serum • May contain antibodies against Schistosoma ▪ Reagent: Lyophilized cercaria ▪ Shrinking of cercaria = presence of antibodies For S. haematobium o Urine examination o Preferred specimen: 24-hour unpreserved urine o Optimized recovery in urine: between noon and 2:00 PM