PARA WEEK 4.pdf

4 intestinal nematodes Hookworms Second most common helminthic infection reported in humans Known to have a worldwide distribution with two species to infect humans: Ancylostoma duodenale necator americanus Habitat: Small Intestine Final Host: Man Diagnostic Stage: Egg/Larva Infective Stage: L3/Fila...

4 intestinal nematodes Hookworms Second most common helminthic infection reported in humans Known to have a worldwide distribution with two species to infect humans: Ancylostoma duodenale necator americanus Habitat: Small Intestine Final Host: Man Diagnostic Stage: Egg/Larva Infective Stage: L3/Filariform Larva (Sheathed) Mode of Transmission: Skin Penetration (direct penetration) (e.g. unprotected feet) eggs Same for all species (indistinguishable) Ovoidal, thin-shelled, and colorless Inside is a germ cell in fragmentation: 2-8 Blastomeres "Morula Ball" formation adult specie common name teeth Ancylostoma duodenale Old World Hookworm 2 pairs Necator americanus American Hookworm American Murderer New World Hookworm semilunar cutting plates Ancylostoma braziliense Cat Hookworm 2 pairs Ancylostoma caninum Dog Hookworm 3 pairs larva l1 (rhabditiform larva) 1st stage larva Short and stout Open Mouth: Feeding Stage Long Buccal Cavity Short / Small Genital Primordium l3 (filariform larva) 2nd stage larva Long and slender Closed Mouth: Nonfeeding Stage Sheathed, pointed tail life cycle Adults live in small intestine Egg in feces, develops rapidly to rhaditiform larva and hatches in soil After 2 molts (molting twice), become filariform larva Filariform larva penetrate skin of man, begins larval migration (enters lymphatics and blood > lung > alveoli > bronchioles > pharynx > small intestine) and then matures into adult Symptoms and Pathology 1. Larval Penetration Human Hookworm Allergic Reaction: Ground itch/Dew itch/Water sore / Mazza Mora Severe itching at the site of larval penetration of skin Erythematous popular rash Animal Hookworm Creeping Eruption or Cutaneous Larva Migrans (CLM) 2. Larval Migration Heart-to-lung migration (ASH): pneumonitis Pulmonary lesions and hemorrhage: Wakana Disease Pneumonia and alveolar hemorrhage, bloody sputum 3. adult infection Tissue damage at the site of attachment Enteritis and pain blood loss and anemia Necator: 0.03 mL blood/day Ancylostoma: 0.26 mL blood/day) Chronic blood lost: Iron Deficiency Anemia Acute gastrointestinal phase demonstrates increased eosinophilia Strongyloides stercoralis Common Name: Threadworm Smallest nematode infecting man Can be a free-living organism Facultative nematode: Free-living: Soil Parasitic (Female): Small Intestine Habitat: Small Intestine Final Host: Man Diagnostic Stage: Rhabditiform Filariform Larva egg: signifies heavy infection Infective Stage: L3 Larva/Filariform Larva (unsheathed) Mode of Transmission: Skin Penetration Internal Autoinfection: chronic and hyperinfection rhabditiform larva filariform larva hookworm threadworm buccal cavity long short Genital Primordium Small Inconspicuous Prominent Conspicuous Sheath Sheathed unsheated tail Pointed notched eggs Rarely found; diagnosed as "Hookworm egg" (indistinguishable) slightly smaller than Hookworm egg well-developed larvae almost always contained in the egg Chinese Lantern appearance Symptoms and Pathology 1. Larval Penetration Allergic reaction at the site of larval penetration "Larva Currens" tracks under skin from worm migration 2. Larval migration Heart-Lung Migration - Pneumonia (signs and symptoms resembling broncopneumonia) 3. Adult Cochin China Diarrhea Vietnam Diarrhea (Intermittent Diarrhea) Strongyloides fuelleborni a primate parasite that has been isolated from a human in africa Causes Swollen Belly Syndrome. a serious life threatening condition characterized by: diarrhea, respiratory distress hypoalbuminemia edema. Diagnosed by detecting the eggs (smaller than S. stercoralis) in stool Anisakis simplex Fish and Marine Mammals Roundworm Sometimes called "Herringworm," "Codworm," or "Sealworm" Causes Herring Disease; common in Japan HOSTS: Definitive Host: Whales/Dolphins 1st Intermediate Host: Copepods 2nd Intermediate Host: Smaller Fishes 3rd Intermediate Host: Larger Fishes (Salmons) Mode of Transmission: Ingestion of raw fish infected with larva (e.g. Sashimi) Symptoms and Pathology: Abdominal pain and granuloma around migrating larva in INTESTINAL WALL Trichostrongylus spp. similar to Hookworm eggs but has pointed eggs an intestinal nematode of herbivores Human infection is usually acquired by ingestion of leafy vegetables carrying the third-stage larva. Oesophagostomum spp. worms resemble Hookworms causes unilocular disease/ “dapaong tumor” (turtle in the belly) Baylisascaris procyonis common name: Raccoon Roundworm causes fatal visceral larva migrans in infants; acquires infection from ingestion of infective eggs Gongylonema spp. Intermediate Host: cockroaches and other insects human infection is through ingestion of these insects or contaminated water G. pulchrum – “Gullet Worm” or “Stitch Worm” Acanthocephala spp. thorny-headed worms Moniliformis moniliformis Macracanthorhynchus hirudinaceus Macracanthorhynchus ingens Bolbosoma Intermediate Host: arthropods (beetles, cockroaches) also accidentally through sashimi