Nematodes Hookworm

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NEMATODES: Hookworms General Info Hookworm (in General) Strongyloides stercoralis CN Threadworm FH Human/Nonhuman (Group) Man H Small intestine Small intestines Life Span Max: 15 years MOT Ingestion (Human) Skin penetration (Nonhuman) Skin penetration DS Embryonated Ova (Stool) Rhabditiform larva (Stool) IS Filariform Larva (Soil) – L3 Filariform Larva Src. of Infection Soil-transmitted helminth (STH) STD Morphology Meromyarian (2-5 cells per dorsal/ventral half) Meromyarian FACULATATIVE Loves warm area = nonfeeding Chemorecept or Ampids Phasmids Attachment/Dental pattern Bite: intestinal mucosa Penetration in intestinal mucosa: Honeycomb intestinal mucosa Parasitic Free living Male Size Refer to a specific parasite Not been reliably identified 0.7mm Posterior Ventrally curved tail Spicules Copulatory spicules Gubernaculum Layer Smaller: Microconspicous Conspicuous (w/o Cephalic alea) Femal e Color Refer to a specific parasite Colorless, semi-transparent Colorless, semi- transparent Covering Fine striated cuticle Size 2.2 mm 1 mm Type Parthogenetic Oviviparus Anterior Slender tapering Esophagus Long slender, 3mm Double bulb esophagus Buccal Cavity Short, 4 indistinct Lips Posterior Short conical tail Vulva 1/3 Length of the body Intestine Continuous to subterminal anus Straight cylindrical tube Uterus 1 Uteris, single file of 8- 12segmented ova [50-58 μm] 2 Horn Uterus [Embryonated eggs]

description

August 25, 2010

Transcript of Nematodes Hookworm

Page 1: Nematodes Hookworm

NEMATODES: HookwormsGeneral Info Hookworm (in General) Strongyloides stercoralis

CN ThreadwormFH Human/Nonhuman (Group) ManH Small intestine Small intestinesLife Span Max: 15 yearsMOT Ingestion (Human)

Skin penetration (Nonhuman)Skin penetration

DS Embryonated Ova (Stool) Rhabditiform larva (Stool)IS Filariform Larva (Soil) – L3 Filariform LarvaSrc. of Infection Soil-transmitted helminth (STH) STDMorphology Meromyarian (2-5 cells per dorsal/ventral half) Meromyarian

FACULATATIVELoves warm area = nonfeeding

Chemoreceptor Ampids ✔ ✔

Phasmids ✔ ✔

Attachment/Dental pattern Bite: intestinal mucosa Penetration in intestinal mucosa: Honeycomb intestinal mucosaParasitic Free living

Male SizeRefer to a specific parasite Not been reliably identified

0.7mmPosterior Ventrally curved tailSpicules Copulatory spiculesGubernaculum Layer Smaller: Microconspicous Conspicuous (w/o Cephalic alea)

Female Color

Refer to a specific parasite

Colorless, semi-transparent Colorless, semi-transparentCovering Fine striated cuticleSize 2.2 mm 1 mmType Parthogenetic OviviparusAnterior Slender taperingEsophagus Long slender, 3mm Double bulb esophagusBuccal Cavity Short, 4 indistinct LipsPosterior Short conical tailVulva 1/3 Length of the bodyIntestine Continuous to subterminal anus Straight cylindrical tubeUterus 1 Uteris, single file of 8-12segmented

ova [50-58 μm]2 Horn Uterus [Embryonated eggs]

Rhabditiform(Feeding stage)>Open buccal cavity>HK: more attenuated

Buccal Cavity

Long buccal cavity [Image from CDC/PHIL]

[Free-living]-225 μm-Elongated Esophagus -Pyriform posterior bulb-Short buccal cavity

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Genital Primordium

Smaller LargerFilariform(Non-feeding stage)>(MOT) Closed buccal cavity

SheathedPointed posterior

550μmNonsheathed

Barbed posterior

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Embroynated Ova> Single thin walled hyaline cell wall> Blastomere (6~8)

Image by Tai Soon Yong Thin shelled ova of Strongyloides stercoralis. Measuring 50µm by 30µm,  they are smaller than Hookworm eggs.  (SOURCE: CDC)

Pathology Pneumonitis/Wakana disease

Ground itch, Coolie itch, Mazza larva, Dev itch

HW anemiaHypoalbuminema

Microcytic Hyperchromic Anemia of IDA

Cochin China Diarrhea/Vietnam Diarrhea

Autoinfection

Hookwrom dermatitis

Pneumonitis/Wakana disease

Ground itch, Coolie itch, Mazza larva, Dew itch

Lung Heart Migration

3 Life Cycle of S. stercoralis1. Direct2. Indirect3. Autoinfection

Dx Harada Mori Culture Method

DFS

Kato technique

Kato-Katz

Conc. Tech=ZnSO4/Brine CT=Centrifugal floatation=FECT

Harada Mori Culture Method

Stoll/Beaver Technique

Baerman Culture Technique

Duodenal aspirate (Beale’s String Test/Entero String Test)

Tx AbendazoleMebendazole

AbendazoleThiabendazole

Prevention(HK & S. stercoralis)

1. Sanitary disposal of human feces2. Wearing of shoes, slippers and boots3. Health education on personal, family and community hygiene

4. Treatment of infected individuals5. Mass chemotheraphy when prevalence is greater than 50%6. Protection of susceptible individuals by improving household

income and diet to prevent malnutrition

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>Human Ancylostoma duodenale Necator americanus

CN Old World Hookworm New World HookwormMOT Ingestion/Skin penetrationSrc. of Infection STH STHMorphology Color Grayish white Grayish white

Cylindrical, Fusiform Cylindrical, FusiformHead Not pointed, curved PointedMouth Thistle shape Funnel shapeEsophagus No gap between esophagus & intestines With gapBody Curvature C-shape S-shapedDental Pattern Adult Ancylostoma duodenale worm. Anterior end with mouth parts visible.

Courtesy of Patrick W Hickey, MD.

2 pair true ventral teeth, 1 pair median teethinconspicuous

Adult Necator americanus worm. Anterior end with mouth parts visible. Courtesy of Patrick W Hickey, MD.

Semi-lunar Cutting plates (Ventral & Dorsal)Conspicuous buccal spear

Posterior Not pointed tailInconspicuous transverse striation

Pointed tailConspicuous transverse striation

MaleSize 8-11mm 5-9mmBursa Bell shaped Fan shapedSpicule Straight, plain, bristle like BarbedDigits Tripartite Bipartite

Female Straight pointy 9-11mmEmbryonated Ova 25,000-30,000 eggs/day 9,000 eggs/day

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>Nonhuman Ancylostoma caninum Ancylostoma braziliense

CN Dog hookworm Cat HookwormFH Dog Dogs/CatMorphology Smallest HWAttachment/Dental pattern

3 pair Ventral teeth 1 pair median teeth

Male

10mm

Bursa: Flare with long slender rays

5mm

Bursa: Round with short shubby rays

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Female 40mm

9mm Pathology CLM: Cutaneous Larva Migrans/Creeping eruption in human

↑EosinophiliaPenetration of stratum granulosum