• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content

Loading…

Flash Player 9 (or above) is needed to view presentations.
We have detected that you do not have it on your computer. To install it, go here.

Like this presentation? Why not share!

Trichuris+enterobius.ppt

on

  • 7,291 views

 

Statistics

Views

Total Views
7,291
Views on SlideShare
7,284
Embed Views
7

Actions

Likes
10
Downloads
58
Comments
2

2 Embeds 7

http://www.slideshare.net 6
http://health.medicbd.com 1

Accessibility

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel

12 of 2 previous next

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment
  • http://www.biosci.ohio-state.edu/~parasite/trichuris.html Erythema /eri’thi:ma/ 红斑
  • 0.8-1.3 cm.in length , spindle-shaped with a long pointed posterior end. The greater part of the body is occupied by the uterus filled with eggs.

Trichuris+enterobius.ppt Trichuris+enterobius.ppt Presentation Transcript

  • Trichuris trichura Enterobius vermicularis Dr Kamran Afzal Classified Microbiologist
  • Taxonomic Classification of Helminths Fasciolopsis (liver fluke) Schistosoma (not leaf shaped!) Taenia (tapeworm) Genus – examples Trematodes Non-segmented, usually leaf-shaped, with two suckers but no distinct head They have an alimentary canal and are usually hermaphrodite and leaf shaped Schistosomes are the exception. They are thread-like, and have separate sexes Cestodes Adult tapeworms are found in the intestine of their host They have a head (scolex) with sucking organs, a segmented body but no alimentary canal Each body segment is hermaphrodite Platyhelminthes Flat worms; dorsoventrally flattened, no body cavity and, if present, the alimentary canal is blind ending Nematodes Round worms; appear round in cross section, they have body cavities, a straight alimentary canal and an anus Metazoa Class Phylum Sub kingdom
  • Taxonomic Classification of Helminths Fasciolopsis (liver fluke) Schistosoma (not leaf shaped!) Taenia (tapeworm) Ascaris (roundworm) Trichuris (whipworm) Ancylostoma (hookworm) Necator (hookworm) Enterobius (pinworm or threadworm) Strongyloides Genus – examples Trematodes Non-segmented, usually leaf-shaped, with two suckers but no distinct head They have an alimentary canal and are usually hermaphrodite and leaf shaped Schistosomes are the exception. They are thread-like, and have separate sexes Cestodes Adult tapeworms are found in the intestine of their host They have a head (scolex) with sucking organs, a segmented body but no alimentary canal Each body segment is hermaphrodite Platyhelminthes Flat worms; dorsoventrally flattened, no body cavity and, if present, the alimentary canal is blind ending Nematodes Round worms; appear round in cross section, they have body cavities, a straight alimentary canal and an anus Metazoa Class Phylum Sub kingdom
  • Characteristics of Nematodes
    • Cylindrical and unsegmented
    • Dioecious (male and female)
    • Complete digestive tract (mouth / esophagus / intestine / anus)
    • Adults: sexually reproductive life cycle stage
    • Larvae: developmental or asexually reproductive life cycle stage
    • Eggs: protective stage of zygote &/or embryo
    • Oviparous: production of eggs, discharged from uterus of female
    • Viviparous: production of embryos/L1 larvae, no rigid encapsulation of embryo
  • Intestinal Parasites : Mode of infection Intestine Hookworm Strongyloides through skin Ascaris Trichuris Enterobius Disseminated Trichinella Ingested Toxoplasmosis Visceral larva migrans Intestine Cryptosporidium Giardia Amoebiasis Site of adult stage or disease Entry of larvae or oncospheres Ingestion of cysts, oocysts or ova
  • Intestinal Parasites : Symptoms Trichuris Tenesmus, prolapsed rectum Amoebiasis Trichuris Hookworm Diarrhoea with blood loss Giardia Cryptosporidium Strongyloides Diarrhoea +/- malabsorption Giardia Cryptosporidium Amoebiasis Ascaris, hookworm, taenia Abdominal pain and distension Parasite Symptoms
  • Case History - 1
    • 8-yr-old schoolgirl visiting Pakistan from Malaysia
    • 1 week history of epigastric pain, flatulence, anorexia, bloody diarrhea
    • No eosinophilia noted
    • Clinical diagnosis of amoebic dysentery made
    • However, microscopy of stool prep…
  • Trichuris trichura The ‘Whip-worm’
  • 50 mm long with a slender anterior and a thicker posterior end The male is smaller and has a coiled posterior end Morphology - of Adult worms
    • Eggs in stool
    • Size: 50-54 µm by 22-23 µm,
    • Shape is a typical barrel
    • Color is yellow-brown
      • Unstained two polar plugs
    • Shell quite thick
    • Contains unembryonated egg
    Morphology - of Eggs
  • Life cycle
  • Life cycle
    • Humans sole host
    • Transmission
      • Fecal-oral via embryonated ova
    • Frequently coexists with ascaris
    • Reservoir
      • Mainly human, others possible but host specificity not well documented
    • Pathogenic potential
      • Low to moderate, dependent on worm numbers and location in LI
    Pathogenesis
    • Entirely intraluminal life cycle—eggs are ingested
    • Eggs hatch in intestines, larvae attach, and develop into adults
    • Female lays 3,000-5,000 eggs daily
    • Worms can pierce capillaries, cause localized hemorrhage, and allow bacteria to leave intestine
  • Clinical Features
    • Frequently asymptomatic
    • Clinical signs/symptoms - Adult worm (Pathogenic stage)
      • Dependent on no. of worms; None to d igestive disturbances, bloody (frank)/ mucoid diarrhea, abdominal pain and distention, rectal prolapse, anemia and weakness
    • Severe infections
      • Tenesmus and rectal prolapse in children
      • Can be fatal in children
      • Rarely, elephantiasis in adults
    • Trichuris trichiura in the large intestine
    • Many worms are present, each with its anterior end embedded in the intestinal mucosa, resulting in the erythema
  • Lab Diagnosis
    • Stool
      • Direct examination (Iodine stain)
      • Eggs
      • Rarely adult worms
    • Blood
      • Eosinophilia
    • Histopathology of the intestinal mucosa
    • PCR
  • Imaging
    • X-Rays Abdomen
      • Plain
      • With contrast / dye
    • CT Scan
  • Treatment and Prevention
    • Albendazole 400 mg once
    • Mebendazole 100 mg BD for 3 days
    • (600 mg, repeated after 2 weeks)
    • Pay attention to personal hygiene and eating habits
  • Case History - 2
    • 11-year-old female
    • Doing poorly in school
    • Not sleeping well
    • Anorectic
    • Complains of itching in rectal region throughout the day
    • A Scotch-tape test reveals…
  • Enterobius vermicularis The ‘Pin-worm’
  • Helminthic Diseases of the Digestive System
  • Epidemiology
    • Enterobiasis most common worm disease of children in temperate zones
    • Pre-school and elementary school children affected most often
    • Consmopolitan, 30%~50% of the children population is infested
    • Most common where people live under crowded conditions (orphanages / large families / kindergartens / primary school)
  • Morphology of Adult
    • Adult
      • Female: White 8~13 mm in size
    • Fusiform body with a long, thin, sharply tapering tail
    • Alae (cuticular extension of head)
    • Prominent bulb – Rhabditiform esophagus
    • The greater part of the body is occupied by the uterus filled with eggs
      • Male: Like female, but about 1/3 to 1/2 size of female
    • The tail is curved, it is rarely seen
  •  
  • Morphology of Eggs
    • Egg
      • Oval, clear and colorless
      • 50 to 60 µm in length, thick shell
      • Flattened on one side
      • Contains a larva
  • Enterobius vermicularis (Pinworm)
  • Transmission
    • Definitive host
      • Human
    • Transmitted by
      • Ingesting Enterobius eggs
  • Pathogenesis
    • Infective stage
      • Infective eggs
    • Eggs are picked up from surroundings and swallowed
      • Being sticky, adhere to door handles (especially toilet doors), bedclothes and mug handles etc
    • After hatching in the small intestine, they develop into adults
    • The location of adult
      • Cecum and colon
    • Anal itching occurs when mature females emerge from intestine to release eggs
      • Life span of female adult is 1-2 months
    • Right after mating, the male dies
      • Therefore, the male worms are rarely seen
    • Self-inoculation is common
  • Life Cycle
  • Life Cycle
  • Clinical Features
    • Mostly asymptomatic
    • Nocturnal anal pruritis is cardinal feature due to migration and laying of eggs
    • Perianal pruritus may lead to excoriations and bacterial superinfection
    • Occasionally, invasion of the female genital tract with vulvovaginitis and pelvic or peritoneal granulomas can occur 
    • Other symptoms : anorexia, irritability, and abdominal pain
    • May have insomnia, possible emotional symptoms
  • Types of infection
    • Infection from environment
    • Auto-infection
      • Female crawls out of anus and release eggs on the perianal region
      • Patient feels anal pruritus
      • Scratching leads to contamination of hands and nails
      • Re-infection is by hand-mouth transmission
    • Retro-infection
      • Some eggs hatch on the perianal skin and become larvae
      • They will crawl back into the anus and mature into adults
  • Laboratory Diagnosis
    • Direct fecal smear
      • Microscopic identification of eggs collected from the perianal area is the method of choice by
        • Scotch tape technique
          • Cellophane tape impression
      • This must be done in the morning, before defecation and washing
    • Alternatively, anal swabs can also be used
    • Brine-floatation method
    • Detection of adult on anal skin at night, when the child is sleeping
    • Larval cultivation
  • Treatment
    • Since the life span of the pinworm is less than two months, the major problem is re-infection
    • Repeat the treatment after 2 weeks
    • Repeated re-treatment may be necessary for a radical cure
    • Albendazole is the drug of choice
    • Mebendazole and Pyrantel pamoate are the alternative drugs
    • Treat and re-treat the patients and carriers
    • Laundering of bedding
    • Individual health
      • Observation and correction of personal hygienic and eating habits
    • Public health
    • Health education
    Prevention