ByGucci AguhShannon Murphy

STRONGLYLOIDES STERCORALIS

Introduction

Strongyloides stercoralis is a common enteric helminthic parasite

“Thread worm” Parasite of man

• 38 Species found in dogs, cats and many other mammals• 2 different life cycle forms

• Free-living• Parasytic

Who gets it? Where?

The Definitive host of Stronglyloides Stercoralis is Humans S. Fulleboni infects Chimpanzees and

Baboons

Geographic Distribution Tropical and Subtropical Areas Cases also occur in temperate zones Most frequently found in rural areas,

Insitutional settings and lower socioeconomic groups

Morphology Adult females measure 2-3 mm in length by 20 to 50 μm.

Long cylindrical Esophagus which occupies 1/3 the length of the worm.

Rhabditiod is (L-1 stage) 180 – 380 by 14-20 μm.

Rhabditoid larvae have a short buccal cavity, an attenuated tail and a prominent genital in its early stage. These features are used to differentiate S. stercoralis from Hookworm rhabditiod larvae.

Morphology Filariform larvae (L3, the infective stage) have a long non bulbous esophagus of about 2/5 of the lenght of the body.

Filariform larvae are slender and have a notched tip of the tail.

Filariform larvae measure 300-600 µm in lenght by 10-20 µm.

Lif

e C

ycle

Rhabditiod Eosophagus

Filariform larvae have a long non bulbous esophagus

The intestinal mucosa during S.stercoralis hyperinfection: a) histological section of the mucosa showing an adult worm, larvae and eggs; b) at higher magnification larvae and eggs within the mucosa; c) cross section of an adult female in the crypt: 2 reproductive tubes and the intestine are visible; d) egg (50-60 by 30-35 µm) of S.stercoralis within the mucosa; e) longitudinal section of an adult female showing a reproductive tube the intestine.

The intestinal mucosa during S.stercoralis hyperinfection:

ab c d

e

The free living females measure about 1 mm in lenght by 50-75 µm: a) a free living female containing embryonated eggs; b) the free living females have a rhabdithoid esophagus; c) particular of the buccal cavity; d) the rhabdithoid esophagus; e) eggs within the free-living female.

ab

c

e

d

Pathogenesis

Frequently is Asymptomatic GI Symptoms

Abdominal Pain and Diarrhea Pulmonary symptoms can occur Dermatological symptoms

Uticarial Rashes in Buttocks and waist area

Immunocompromised patients Abdominal Pain, Distension, shock,

pulmonary and neurological complications with septicemia and is potentially fatal.

Diagnosis Larvae in stool using concentration

methods. Filter paper technique and wet mount

preparation. larvae in duodenal fluid. Serial Samples. Antibody detection. Morphological comparison to other

parasites.

Treatment & Prevention

Anthelmintics Ivermectine (200 micrograms/Kg in a single

dose) Albendazole (25 mg/Kg twice a day for 2

days) Prevention

Teaching sanitation Proper disposal of human waste

References

http://www.dpd.cdc.gov/dpdx/html/Strongyloidiasis.htm Center for Disease Control and Prevention

http://www.diagnose-me.com/cond/C654193.html

Strongyloides Stercoralis. http://www.cdfound.to.it/html/str1.htm#ss0