Strongyloides stercoralis Adult Worm Under the Microscope: Introduction, Lab Diagnosis and Treatment

Strongyloides

Strongyloides stercoralis is a medical importance parasitic roundworm causing the disease called strongyloidiasis. It recovered from stool specimen and the specimen inoculated into Muller-Hinton agar. After overnight incubation, the plate was observed under microscope at 10X objective, and this type of adult structure of Strongyloides stercoralis was seen.

Introduction of Strongyloides Stercoralis

Strongyloides stercoralisis a human pathogenic parasitic roundworm causing the disease strongyloidiasis. The Strongyloides stercoralis nematode can parasitize humans. The adult parasitic stage lives in tunnels in the mucosa of the small intestine. The genus Strongyloides contains 53 species.

Geographic Distribution

This infection is associated with fecal contamination of soil or water. so, it is a very rare infection in developed economies than in developing S. stercoralis can be found in areas with tropical and subtropical climates. Estimates of the number of people infected vary with one estimate putting the figure at 370 million worldwide.

Life Cycle

It completes into two stages

a) Free-living cycle

b) Parasitic cycle

Morphology of Strongyloides stercoralis

Male having a size of about 0.9 mm whereas female larger i.e. from 2.0 to 2.5 mm.

Males can be distinguished from females by two these structures:

the spicules

and gubernaculum.

Autoinfection

It is an unusual feature of S. stercoralis. Auto infection is the development of L1 into small infective larvae in the gut of the host. These auto infective larvae penetrate the wall of the lower ileum or colon or the skin of the perianal region, enter the circulation again, travel to the lungs, and then to the small intestine, thus repeating the cycle.

Symptoms

Initially, many people infected are asymptomatic. Anyway, Symptoms include

dermatitis:

swelling,

itching,

larva currens,

and mild hemorrhage at the site where the skin has been penetrated.

Spontaneous scratch-like lesions may be seen on the face or elsewhere.

Diagnosis

Fecal wet preparation :

showing larvae (juvenile, rhabditiform, or filariform)

Culturing fecal samples on agar plates:

Trekking of Strongyloides on an agar plate

Serology:

serodiagnosis through ELISA and duodenal fumigation.

Treatment

Choice of drugs are-

Albendazole
Thiabendazole
ivermectin
mebendazole
and piperazine

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