TRICURIS TRICHIURA - STRONGYLOIDES STERCORALIS - SECOND MBBS STUDENTS - UNDERGRADUATE STUDENTS - MEDICAL COLLEGE - POWERPOINT

1. Trichuriasis
Strongyloidiasis
Dr. R. Someshwaran, MD., Assistant professor,
Department of Microbiology,
Karpagam faculty of Medical Sciences & Research

2. Objective of today’s class
• To define the General features,
Species and life cycle of Genus
Trichuris and Strongyloides
• To elucidate briefly on the clinical
spectrum, lab diagnosis and
management of Trichuriasis and
Strongyloidiasis.

3. INTRODUCTION
Intestinal nematode:
Trichuris trichiura - Ingestion
Strongyloides stercoralis – Skin penetration

4. MORPHOLOGY
I. Morphology:
• Adult: the worm looks like a buggy whip
• anterior 3/5 is slender and the posterior 2/5 is
thick. Pinkish gray in color.
• The female worm is 3-5 cm in length and has a
long slender esophageal region.
• The male is smaller than the female and has a
curved tail.
• The reproductive organs of male and female
are all double tubule.

5. Adult worm of of T. trichiura

6. MORPHOLOGY
• Egg: it is barrel or spindle in shape and 50 x
20µm in size. It is brownish and has a
translucent polar plug at either ends. The
content of the egg is an undeveloped cell

7. II. Life Cycle
1. Site of inhabitation: cecum
2. Infective stage: Fertilised / Embryonic egg
3. Infective mode and route: passively swallowed by the mouth
4. Without intermediate host and reservoir host
5. The life span of the adult is about 3-5years.
deposit 3weeks ingested by man
Adults Eggs Infective eggs larvae hatch out
in small intestine
invade the intestinal wall return to the intestinal lumen Adults
develop 3-10 days

8. LIFE CYCLE

9. III. Pathogenesis:
1. Light infection:
Asymptomatic
2. Middle infection:
Clinical manifestations are usually abdominal
pain,
anorexia, diarrhea, constipation .
3. Heavy infection:
Bloody diarrhea, emaciation, prolapse of the
anus may occur.

10. IV. Diagnosis:
Discover the eggs in feces by saturated brine
flotation method or direct fecal smear.
V. Treatment and prevention:
Same as those of ascariasis. Take
Mebendazole 3 days for a treatment course
and repeat next week.

11. TRICHURIASIS

12. STRONGYLOIDIASIS
• Strongyloides fuelleborni
• Strongyloides papillosus
• Strongyloides stercoralis

13. Definition
• Human parasitic disease caused by nematode
S. Stercoralis.
• Mostly in tropical, subtropical area and
temperate climate.
• Affect 30-100 million annually.
• Has two unique life cycle:
• Free life cycle and Parasitic life cycle.

14. Definition
• Cause by direct contact with contaminated soil
and recreational activities.
• Children highly affected to bad sanitation.
• S. stercoralis is a 2 mm long intestinal worm

15. Rhabditiform (L1) larva of Strongyloides stercoralis is about 0.3 mm
long. (1 µm = 0.001 mm)

16. LIFE CYCLE

17. Larvae

18. Pathology
• Invasive : Skin Penetration.
• Pulmonary: During Cycle or Immigration.
• Intestinal: Tissue Destruction

19. Symptoms and Signs of
Hyperinfection
Anemia, constipation
Cough, diarrhea
Eosinophilic pneumonitis (during
larvae migration through the
lungs)
Nausea, vomiting
weight loss.

20. Symptoms of Immuno-suppressed patients
(organ transplant) or immunocompromised
patients (HIV):
• Death
• neurological and pulmonary
complications
• shock.

21. Diagnosis
 Stool culture most effective way.

22. Treatment
 Strongyloidiasis is treated with:
 Ivermectin.
 Tthiabendazole.
 No public health strategies for controlling are
active at global level.

23. Take home message
• Trichuris trichiura – whip worm - ingestion
• Strongyloides stercoralis – skin penetration
• Eggs of Trichuris is bile stained with double
layered coat and has mucus plug at both poles
• Strongyloides spp., - Ground itch

24. THANK YOU