TrichuriasisStrongyloidiasis

Dr. R. Someshwaran, MD., Assistant professor,Department of Microbiology,

Karpagam faculty of Medical Sciences & Research

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.

INTRODUCTION

Intestinal nematode:Trichuris trichiura - IngestionStrongyloides stercoralis – Skin penetration

MORPHOLOGYI.       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.•

Adult worm of of T. trichiura

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

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

LIFE CYCLE

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.

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.

TRICHURIASIS

STRONGYLOIDIASIS

• Strongyloides fuelleborni• Strongyloides papillosus• Strongyloides stercoralis

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.

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

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

LIFE CYCLE

Larvae

Pathology

• Invasive : Skin Penetration.

• Pulmonary: During Cycle or Immigration.

• Intestinal: Tissue Destruction

Symptoms and Signs of Hyperinfection

Anemia, constipationCough, diarrheaEosinophilic pneumonitis (during larvae migration through the lungs)

Nausea, vomitingweight loss.

Symptoms of Immuno-suppressed patients (organ transplant) or immunocompromised

patients (HIV):

• Death• neurological and pulmonary

complications• shock.

Diagnosis

Stool culture most effective way.

Treatment

Strongyloidiasis is treated with: Ivermectin. Tthiabendazole. No public health strategies for controlling are

active at global level.

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

THANK YOU