intro & ascaris
TRANSCRIPT
-
7/31/2019 Intro & Ascaris
1/21
Helminthology
Parasitology Dept.
-
7/31/2019 Intro & Ascaris
2/21
Definitions
Helminthology is the science about helminthes
(worms).
Helminthes are divided into: Nemathelminthes
and Platyhelminthes
-
7/31/2019 Intro & Ascaris
3/21
Definitions
Due to living sites : Ectoparasites and
Endoparasites
Due to living habits: Facultative and Obligate
parasites Due to life cycle: Periodic and Permanent
parasites
Due to the host: Monoxen and Polyxen parasites
-
7/31/2019 Intro & Ascaris
4/21
Terminology
Host: definitive, reservoir, intermediate,
paratenic
Vector: biologic and mechanic
Parasitism
Commensalisms
Mutualism
-
7/31/2019 Intro & Ascaris
5/21
Nematodes
Half million species
50% free living
Animal & plant parasitesAnimal
vertebrate & invertebrate hosts
infection by ingestion or penetration
-
7/31/2019 Intro & Ascaris
6/21
Nematodes
Generally elongated, cylindrical & tapered
at each end (99%)
Fluid filled pseudocoelom longitudinal
muscle only
No vasculature or respiratory system
Usually sexual dimorphism (someparthenogenesis)
-
7/31/2019 Intro & Ascaris
7/21
Nematodes
Males usually smaller than females
Most between 1 mm and 150 cm
Colourless translucent to opaque with
an elastic cuticle
-
7/31/2019 Intro & Ascaris
8/21
Soil Transmitted Helminthiasis ( STH )
nematode infections
transmitted via soil medium either
1. Ingestion of embryonated eggs
2. Skin penetration by infective larvae
refers to these helminths:
Ascaris lumbricoidesTrichuris trichiura
HookwormsStrongyloides stercoralis
Toxocara spp.
Common
STH
agents
-
7/31/2019 Intro & Ascaris
9/21
Habitat of STH in host
Large intestine
Small intestine
Trichuris trichiura
A. lumbricoides
Hookworms
S. stercoralis
-
7/31/2019 Intro & Ascaris
10/21
Infections STH associated with:
Poverty and poor condition
Inadequate sanitation and water supplies
Soil quality and climate
Poor personal and environmental hygiene
Poor health awareness
-
7/31/2019 Intro & Ascaris
11/21
Ascaris lumbricoides
-
7/31/2019 Intro & Ascaris
12/21
Ascaris lumbricoides
Morphology
-
7/31/2019 Intro & Ascaris
13/21
Ascariasis
Etiology: Ascaris lumbricoides ( roundworm )
Habitat : small intestine, especially jejunum and upper ileum
Morphology:
Adult large, broad, cylindrical, tapers at both ends
- light cream pinkish whitish
- female bigger than male
Male
spicule
FemaleVulval opening
between anterior and
midlle 1/3 body
-
7/31/2019 Intro & Ascaris
14/21
Ascarismouth partventral view
3 fine toothed lips
2 ventral lips
1 dorsal lip
covered with sensory papillae
-
7/31/2019 Intro & Ascaris
15/21
Ascaris lumbricoides
Morphology
Egg consists of three layers (walls):
albuminoid (protein), hyaline, and lipoid
Due to the albumin layer: corticated ordecorticated eggs
Due to the content: fertilized, unfertilized,
or infectious eggsEggs resistant to desiccation
-
7/31/2019 Intro & Ascaris
16/21
Fertilized eggs:Rounded, have a thick shell, with anexternal mammillated layer that is oftenstained brown by bileSize: approximately 60 m in diameter
when spherical, and up to 75 m whenovoid.
Unfertilize:elongated and larger (up to 90 m in
length); their shell is thinner; and theirmammillated layer is more variable,either with large protuberance
Morphology:
-
7/31/2019 Intro & Ascaris
17/21
Ascariseggs
fertilized unfertilized
mammilated
semi-
decorticated
-
7/31/2019 Intro & Ascaris
18/21
Ascaris lumbricoides
Life Cycle
World-wide distribution
Ascaris lumbricoides requires no
intermediate host but only the final host
The essential host is human being, but it
also able to grow in swine and primate
-
7/31/2019 Intro & Ascaris
19/21
Ascaris lumbricoides
Life CycleAdult worms in small
intestine, produce eggswhich are excreted with
stool
tracheal migration
Lung passage
Eggs cleavage underoptimal condition in soil
embryonated eggs
Ingested/swallowed byhuman
Hatched in the upper part
of small intestine
Invade blood vessels
http://f/bahan%20kuliah%20ppt/Nematoda/hyperlink%20tracheal%20migration.ppthttp://f/bahan%20kuliah%20ppt/Nematoda/hyperlink%20tracheal%20migration.ppt -
7/31/2019 Intro & Ascaris
20/21
3 weeks
Prepaten Period: 2 months
-
7/31/2019 Intro & Ascaris
21/21